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Cyclone Chido was an “intense tropical cyclone”, equivalent to a category 4 hurricane in the Atlantic. It made landfall in Mayotte, a small island lying to the north-west of Madagascar on December 14, generating wind gusts approaching 155mph (250km/hr). Later on, it hit Mozambique, East Africa with the same ferocity.

This storm skirted north of Madagascar and affected the Comoros archipelago before making landfall in Mozambique. It is well within the range of what is expected for this part of the Indian Ocean. But this region has experienced an increase in the most intense tropical cyclones in recent years. This, alongside its occurrence so early in the season, can be linked to increases in ocean temperatures as a result of climate change.

News of the effects of tropical cyclone Chido in Mayotte, Mozambique and Malawi continues to emerge. Current estimates suggest 70% of Mayotte’s population have been affected, with over 50,000 homes in Mozambique partially or completely destroyed.

Ongoing conflict in Mozambique and undocumented migration to Mayotte will have played a key role in the number of deaths and the infrastructure damage.

Assessing how these cyclones characteristics are changing across southern Africa is part of the research we are involved in. Our team also studies how to build resilience to cyclones where conflict, displacement and migration magnify their effects.

A human-made disaster?

The risk that tropical cyclones pose to human life is exacerbated by socioeconomic issues. Migrants on Mayotte, many of whom made perilous journeys to escape conflict in countries such as the Democratic Republic of Congo, now make up more than half of the island’s population.

Precarious housing and the undocumented status of many residents reportedly made the disaster more deadly, as people feared evacuation would lead them to the police. On islands with poor infrastructure such as Mayotte, there is often simply nowhere safe to go. It takes many days for the power network and drinking water supply to be restored.

The situation is particularly complex in Mozambique. The ongoing conflict and terrorist violence, coupled with cyclones, including Kenneth in 2019, has caused repeated evacuations and worsening living conditions. Cabo Delgado and Nampula in the far north of Mozambique, the provinces most affected by both Chido and the conflict, rank among the poorest and most densely populated in the country due to limited education, scarce livelihood options and an influx of people displaced by violence.

As of June 2024, more than half a million people remained without permanent homes in the region, many living in displacement camps. That number is likely to rise significantly after Chido.

Compounding the crisis, Chido’s landfall so early in the cyclone season meant that the usual technical and financial preparations were not yet fully ramped up, with low stock levels delaying the timely delivery of aid. Unrest following elections in November hampered preparations further, cutting the flow of resources and personnel needed for anticipatory action and early response.

Tropical cyclones in a warmer world

Warmer sea surface temperatures not only provide more fuel for stronger storms, but may also expand the regions at risk of tropical cyclones.

The Indian Ocean is warming faster than the global average, and is experiencing a staggering increase in the proportion of storms reaching the intensity of Chido.

Climate simulations predict that storms will continue getting stronger as we further warm our world, and could even lead to an unprecedented landfall as far south as the Mozambican capital, Maputo.

Scientists carry out attribution studies to determine how climate change contributed to specific events. Scientists undertaking rapid attribution studies of Chido have found that the ocean surface temperatures along the path of the storm were 1.1°C warmer than they would have been without climate change. So, temperatures this warm were made more than 50 times more likely by climate change. Another study focusing on Chido itself concluded that the cyclone’s winds were 5% faster due to global heating caused by burning fossil fuels, enough to bump it from a category 3 to a category 4 storm.

Intense winds are not the only hazard. Scientists are confident that tropical cyclones will dump more rain as a result of climate change. A trend towards slower-moving storms has been observed, causing more of that rain to accumulate in a single location, resulting in floods.

Cyclone Freddy delivered a year’s worth of rain to southern Malawi in just four days in March 2023. Storm surges, exacerbated by sea level rise, also raise the scale of flooding, as in the devastating Cyclone Idai in March 2019. An increase in the number of storms that rapidly intensify, as Chido did before landfall in Mayotte has also been linked to climate change, which makes it harder to provide early warnings.

To improve resilience to future cyclones, conflict, migration and social dynamics must be considered alongside climate change, without this, displaced and migrant communities will continue to be the most affected by the risks that climate change poses.

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Russia’s former president and current deputy head of its security council, Dmitry Medvedev, has declared that the editors of the Times newspaper in the UK are now “legitimate military targets”.

Medvedev, who is one of Vladimir Putin’s closest allies, was responding to the newspaper’s coverage of the recent assassination of Russia’s chemical weapons chief, Igor Kirillov, in Moscow on December 17. The paper’s leading article referred to his killing by an explosive device hidden in a scooter as a “legitimate act of defence by a threatened nation”.

Medvedev took to Telegram to denounce the article, writing: “Those who carry out crimes against Russia … always have accomplices. They too are now legitimate military targets. This category could also include the miserable jackals from the Times who cowardly hid behind their editorial. That means the entire leadership of the publication.”

The assassination of Kirillov, who was in charge of Russia’s chemical, biological and nuclear defence forces, came a day after he had been charged by Ukraine in absentia with war crimes over Russia’s use of chemical weapons in the ongoing war.

Once seen as a liberal reformer when he temporarily took over Russia’s presidency between 2008 and 2012, Medvedev has since reinvented himself as a pro-war hawk who regularly makes outlandish or extreme statements on social media.

In May 2023, following a drone attack on the Kremlin, Medvedev posted a message on Telegram saying there were “no options left other than the physical elimination of [the Ukrainian president] Zelenskyy and his clique”. The post prompted Ukraine’s foreign minister, Dmytro Kuleba, to respond in an interview that “Medvedev should drink less vodka before going on Telegram”.

In his most recent outburst, Medvedev mirrored the rhetoric used in the Times editorial, claiming that by the same logic, all of Kyiv’s “accomplices” – whether decision-makers in Nato or journalists justifying Ukraine’s actions – are active participants in a war against Russia. This makes them “legitimate military targets” who need to “be careful” even in London, where “anything goes”.

His master’s voice? Dmitry Medvedev with Vladimir Putin in 2019.
EPA-EFE/Ekaterina Shtukina/Sputnik/Kremlin pool

Part of a pattern

Medvedev’s comments, while extreme, fall within a broader pattern of Russian officials using humour or courting controversy to justify their positions or ensure international press coverage. But they are also part of an escalation in Russian attacks on freedom of expression and the press.

Prior to the full-scale invasion of Ukraine, Russia’s media environment was restricted. Opposition viewpoints could, however, still be accessed relatively easily from a range of sources, including the regional press, online outlets and the political blogosphere. But the Kremlin has gradually chipped away at these possibilities by increasing restrictions on independent media and social media users alike.

These restrictions were ramped up even further following Russia’s invasion of Ukraine in February 2022. Criticism of the armed forces and spreading what the Kremlin deems “false information” about the so-called “special military operation” were criminalised.

Anti-war activists now routinely face conviction for justifying terrorism, and well-respected news outlets such as Ekho Moskvy have been forced to close. Journalists from Russia and abroad have been tried, convicted and incarcerated for allegedly violating these laws. They are often held in harsh conditions, in isolation and without access to adequate medical care.

But it is not just journalists and activists within Russia who have come under threat from this increasingly authoritarian regime. As well as its military incursions into Georgia in 2008 and eastern Ukraine since 2014, Russian intelligence organisations have been blamed for a number of targeted provocations abroad in recent years. In the case of the 2018 Salisbury poisonings, these resulted in fatalities on British soil.

Russian involvement is, of course, always denied. Kremlin propaganda uses a range of disinformation tactics to hide Russia’s culpability. With the Salisbury poisonings, this included an outlandish television interview on Russia’s RT network, where the main suspects claimed to be visiting health supplements salesmen. My research at the time showed that online audiences universally rejected their story, but incredulity over the interview overtook public anger.

Contrasting values

As my research has shown, extreme statements and conspiracy theories circulate rapidly and widely in today’s international media environment. With this in mind, it is common for the Kremlin and its proxies to mirror accusations back towards other parties and accuse them of hypocrisy.

Taking questions from a US journalist in his end-of-year press conference and phone-in on December 19, Putin was asked about the “failure” of the special military operation in Ukraine. The reporter went on to describe Putin’s position as “weaker” than that of the incoming US president, Donald Trump.

Putin insinuated that the very fact this US journalist was included in the event showed a better treatment by Russia of “esteemed” international journalists than Russian journalists receive from the US.

This is patently untrue. Wall Street Journal reporter Evan Gershkovich was imprisoned in Russia for 16 months on trumped-up espionage charges, after being detained in March 2023 while covering the effect of western sanctions on the Russian economy.

Wall Street Journal reporter Evan Gershkovich arriving in the US following a 26-person prisoner swap between Russia, the US and five other countries in August 2024.
Jim Lo Scalzo/EPA

Russia’s crackdown on freedom of speech and freedom of the press is precisely because authoritarian regimes recognise they are incredibly vulnerable to the free and open-ended enquiry that my co-authors and I have argued is so crucial to defend.

As a spokesperson for the UK prime minister, Keir Starmer, noted in response to Medvedev’s latest comments: “A free press is a cornerstone of our democracy.” Läs mer…

A ruling by the UK’s Special Immigration Appeals Commission has revealed that a Chinese businessman with links to King Charles’ younger brother, Prince Andrew, has been banned from Britain. The commission was upholding a decision originally taken in 2023 by the then home secretary, Suella Braverman, to exclude a man subsequently named as Yang Tengbo.

Britain’s Security Service, MI5, had advised the commission that Yang posed “a risk to UK national security”. Reports have noted Yang’s visits to royal events at the request of the prince and his communications with one of Andrew’s senior advisers, Dominic Hampshire.

That Andrew might have been cultivated by an agent of the Chinese government will come as no surprise to anyone who has studied the work of intelligence agencies. Their ideal target will not necessarily be someone who sympathises with the regime they serve. Indeed with the collapse of the ideological certainties of the cold war, this has become increasingly unlikely.

Rather, a target will probably be someone who has particular weaknesses that can be exploited, often revolving around money or sex. They are seldom at the very pinnacle of power. But that, in itself, can leave them resentful and hungry for affirmation.

An exaggerated sense of self-importance can render them even more pliable. This can make for a complex relationship between intelligence predator and their prey.

In Andrew’s case, there are indications that members of his circle actually talked up the prince’s importance as a political contact. The commission’s ruling quoted a message from Hampshire to Yang in March 2020 after the latter had been invited to attend the Prince’s 60th birthday party.

Hampshire told Yang: “I also hope that it is clear to you where you sit with my principal and indeed his family. You should never underestimate the strength of that relationship. …outside of his closest internal confidants, you sit at the very top of a tree that many, many people would like to be on.”

Those more familiar with the workings of the British government might be sceptical about the height of the branches Yang had reached. King Charles is, after all, a constitutional monarch with few formal powers. And Andrew has become an increasingly marginalised figure within the royal family.

A steady stream of revelations about his relationship with sex-trafficker and paedophile Jeffrey Epstein has left him increasingly out in the cold. He was stripped of his role as UK trade envoy in 2011 and was then forced to step down from public duties in 2019. So why bother trying to court him?

Clues are provided in an important survey of the links between the royal family and the intelligence community published by international history specialists Richard Aldrich and Rory Cormac in 2021. As they note, before 2011, Andrew had enjoyed a long career in the royal navy and then as a British trade envoy, becoming closely involved in the sensitive and secretive world of UK arms sales.

In 2010, the Wikileaks revelations suggested Andrew had been fiercely critical of the Serious Fraud Office for almost derailing a deal with Saudi Arabia and that his inside knowledge might have extended to some dark corners of the arms trade and its methods. There were also reports that the UK’s foreign intelligence service, MI6, was concerned that a former US deputy police chief close to the investigation into the Epstein affair might have leaked details to Russia, leaving Andrew open to blackmail.

So Andrew probably was a tempting target, combining personal vulnerability with knowledge that could, at the very least, be embarrassing to the UK. But then, to borrow former US defense secretary Donald Rumsfeld’s vivid phrase about Iraq, the British establishment has long provided foreign intelligence agencies with “a target-rich environment”. And the waters tend to be muddied by the ease with which legitimate contacts based on cultural and trade diplomacy can morph into something more sinister.

Broader concerns

The ruling of the Special Immigration Appeals Commission quoted from a statement by the director-general of MI5 from July 2022 which distinguished between legitimate diplomacy and “what we call interference activity – influencing that is clandestine, coercive or corruptive”. Yet, in practice, the distinction is often opaque.

When darker forces are at work, it often only becomes apparent as a result of prolonged surveillance of those involved. And that, in turn, assumes Britain’s spies are actually doing their job. Various bodies have questioned whether they are.

In a July 2020 report, the parliamentary intelligence and security committee criticised the intelligence community for not being more curious about certain aspects of Russian activity. The possibility of Kremlin interference in the 2016 Brexit referendum was a significant concern.

The implication – that intelligence officials had been nervous about getting involved in such a sensitive political issue – was rather borne out by the fate of the committee’s report itself. It was delivered to then prime minister Boris Johnson in October 2019 but was not released to the public until well after his pro-Brexit government had won the general election of December that year.

Nor is the Labour party without questions to answer. At the same time as the Prince Andrew scandal was unfolding, Christine Lee, who donated £584,177 to the office of the Labour MP Barry Gardiner, lost a claim against MI5 which had accused her of engaging in political interference on behalf of China. Gardiner has said in response that none of the donations “according to MI5, came from an illegal source” and that he has “ceased all contact” with Lee following the MI5 warning.

Prince Andrew’s behaviour is part of a wider picture and speaks to the general need for higher standards in British public life. Stricter rules on political donations to prevent foreign interference in British politics are long overdue. And people of political influence, including members of both houses of parliament, should be far more closely scrutinised over their relationships with foreign officials and business people. National security, as the term implies, very much begins at home. Läs mer…

Trust in Britain’s institutions is in bad shape, according to recent data from the European Social Survey.

Trust is important because a good deal of governing involves trying to persuade people to do things or convince them that things will get better in the future. This is increasingly difficult to do if trust is in decline. Trust in political institutions is particularly important when governments have to make unpopular decisions, such as raising taxes.

Data covering a 20-year period shows a marked decline in trust in parliaments, political parties and politicians. The following question is asked in the European Social Surveys over time:

Please tell me on a score of 0-10 how much you personally trust each of the following institutions. 0 means you do not trust an institution at all, and 10 means you have complete trust in it.

The decline in trust began around the time of the 2016 survey, when the lowest level of trust in politicians and political parties was recorded in 20 years of doing the survey. Parliament has done a bit better, but decline in trust for it is still quite marked. It is no coincidence that this decline started in 2016 – the year of Brexit.

Average trust scores for British institutions, 2002-2022

Trust on the slide.
P Whiteley, CC BY-ND

But the European Social Survey carries another important measure of trust – our trust in fellow citizens. A question in the surveys asks how trusting respondents felt about other people on an 11-point scale, with a high score indicating that people are trusting.

Average trust scores in other people in Britain, 2002-2022

Trust in other people.
P Whiteley, CC BY-ND

After a shaky start at the beginning of the millennium, trust in other people increased significantly in Britain in 2006, to over 5.35 on the 11-point scale. It then dropped in 2008, the year of the financial crisis. The recovery from this decline was in place by 2010. It is noticeable that the trust scores fell again in 2018, when the political consequences of Brexit were making themselves felt. Trust revived again in 2020 during the pandemic.

So, our trust in each other is in healthier shape than our trust in institutions. This is important because trust in others is a key measure of social capital – the willingness of people to work together to solve social and economic problems in society. The importance of social capital in creating prosperity in the US was highlighted by the American political scientist Bob Putnam in his best-selling book, Bowling Alone.

Trust is lacking in British politicians.
Flickr/UK Parliament, CC BY-NC-ND

There is now a large literature on social capital and trust, some of it focusing specifically on Britain. The findings are that trust promotes prosperity for a number of reasons. If people trust each other, they are more likely to volunteer. This free labour helps to provide a social safety net, which increases prosperity for all – even if it is not fully recognised in the national income statistics.

High-trust countries like Denmark and Sweden also have low levels of corruption – and corruption is a blocker to growth. In a high-trust environment, the costs of doing business are lower because there is less need for elaborate contracts, expensive lawyers and lots of litigation to make other people behave properly. This is, in part, why high-trust countries are richer than low-trust countries.

It’s well established that economic growth is driven by investment in innovation, skills and transport, extra manufacturing capacity and greater workplace productivity. However, it is also the case that social capital helps to create economic growth. In researching this across a variety of countries, I found that trust was very important in stimulating economic growth alongside these other factors.

Government has limited direct influence on social capital, but it can encourage it by investing in voluntary organisations and increasing transparency in its dealings with the public.

Britain has suffered from a lack of investment in capital spending and infrastructure, and has neglected investment in education over the past 15 years. Social capital seems to be in much better shape, and faced with the significant challenge of restoring growth, the UK government needs to pull every lever at its disposal. It can repair trust in politics with its own actions, and this is likely to help with sustaining social capital, which is part of the solution to restoring economic growth. Läs mer…

We named him Squirt – not because he was the smallest of the 16 cuttlefish in the pool, but because anyone with the audacity to scoop him into a separate tank to study him was likely to get soaked. Squirt had notoriously accurate aim.

As a comparative psychologist, I’m used to assaults from my experimental subjects. I’ve been stung by bees, pinched by crayfish and battered by indignant pigeons. But, somehow, with Squirt it felt different. As he eyed us with his W-shaped pupils, he seemed clearly to be plotting against us.

A common cuttlefish (Sepia officinalis) in Portugal’s Arrábida Natural Park.
Diego Delso/Wikipedia, CC BY-SA

Of course, I’m being anthropomorphic. Science does not yet have the tools to confirm whether cuttlefish have emotional states, or whether they are capable of conscious experience, much less sinister plots. But there’s undeniably something special about cephalopods – the class of ocean-dwelling invertebrates that includes cuttlefish, squid and octopus.

As researchers learn more about cehpalopods’ cognitive skills, there are calls to treat them in ways better aligned with their level of intelligence. California and Washington state both approved bans on octopus farming in 2024. Hawaii is considering similar action, and a ban on farming octopus or importing farmed octopus meat has been introduced in Congress. A planned octopus farm in Spain’s Canary Islands is attracting opposition from scientists and animal welfare advocates.

Critics offer many arguments against raising octopuses for food, including possible releases of waste, antibiotics or pathogens from aquaculture facilities. But as a psychologist, I see intelligence as the most intriguing part of the equation. Just how smart are cephalopods, really? After all, it’s legal to farm chickens and cows. Is an octopus smarter than, say, a turkey?

A deepwater octopus investigates the port manipulator arm of the ALVIN submersible research vessel.
NOAA, CC BY

A big, diverse group

Cephalopods are a broad class of mollusks that includes the coleoids – cuttlefish, octopus and squid – as well as the chambered nautilus. Coleoids range in size from adult squid only a few millimeters long (Idiosepius) to the largest living invertebrates, the giant squid (Architeuthis) and colossal squid (Mesonychoteuthis) which can grow to over 40 feet in length and weigh over 1,000 pounds.

Some of these species live alone in the nearly featureless darkness of the deep ocean; others live socially on active, sunny coral reefs. Many are skilled hunters, but some feed passively on floating debris. Because of this enormous diversity, the size and complexity of cephalopod brains and behaviors also varies tremendously.

Almost everything that’s known about cephalopod cognition comes from intensive study of just a few species. When considering the welfare of a designated species of captive octopus, it’s important to be careful about using data collected from a distant evolutionary relative.

Marine biologist Roger Hanlon explains the distributed structure of cephalopod brains and how they use that neural power.

Can we even measure alien intelligence?

Intelligence is fiendishly hard to define and measure, even in humans. The challenge grows exponentially in studying animals with sensory, motivational and problem-solving skills that differ profoundly from ours.

Historically, researchers have tended to focus on whether animals think like humans, ignoring the abilities that animals may have that humans lack. To avoid this problem, scientists have tried to find more objective measures of cognitive abilities.

One option is a relative measure of brain to body size. The best-studied species of octopus, Octopus vulgaris, has about 500 million neurons; that’s relatively large for its small body size and similar to a starling, rabbit or turkey.

More accurate measures may include the size, neuron count or surface area of specific brain structures thought to be important for learning. While this is useful in mammals, the nervous system of an octopus is built completely differently.

Over half of the neurons in Octopus vulgaris, about 300 million, are not in the brain at all, but distributed in “mini-brains,” or ganglia, in the arms. Within the central brain, most of the remaining neurons are dedicated to visual processing, leaving less than a quarter of its neurons for other processes such as learning and memory.

In other species of octopus, the general structure is similar, but complexity varies. Wrinkles and folds in the brain increase its surface area and may enhance neural connections and communication. Some species of octopus, notably those living in reef habitats, have more wrinkled brains than those living in the deep sea, suggesting that these species may possess a higher degree of intelligence.

Holding out for a better snack

Because brain structure is not a foolproof measure of intelligence, behavioral tests may provide better evidence. One of the highly complex behaviors that many cephalopods show is visual camouflage. They can open and close tiny sacs just below their skin that contain colored pigments and reflectors, revealing specific colors. Octopus vulgaris has up to 150,000 chromatophores, or pigment sacs, in a single square inch of skin.

Like many cephalopods, the common cuttlefish (Sepia officinalis) is thought to be colorblind. But it can use its excellent vision to produce a dizzying array of patterns across its body as camouflage. The Australian giant cuttlefish, Sepia apama, uses its chromatophores to communicate, creating patterns that attract mates and warn off aggressors. This ability can also come in handy for hunting; many cephalopods are ambush predators that blend into the background or even lure their prey.

The hallmark of intelligent behavior, however, is learning and memory – and there is plenty of evidence that some octopuses and cuttlefish learn in a way that is comparable to learning in vertebrates. The common cuttlefish (Sepia officinalis), as well as the common octopus (Octopus vulgaris) and the day octopus (Octopus cyanea), can all form simple associations, such as learning which image on a screen predicts that food will appear.

Some cephalopods may be capable of more complicated forms of learning, such as reversal learning – learning to flexibly adjust behavior when different stimuli signal reward. They may also be able to inhibit impulsive responses. In a 2021 study that gave common cuttlefish a choice between a less desirable but immediate snack of crab and a preferred treat of live shrimp after a delay, many of the cuttlefish chose to wait for the shrimp.

Cuttlefish perform in an experiment adapted from the Stanford “marshmallow test,” which was designed to see whether children could practice delayed gratification.

A new frontier for animal welfare

Considering what’s known about their brain structures, sensory systems and learning capacity, it appears that cephalopods as a group may be similar in intelligence to vertebrates as a group. Since many societies have animal welfare standards for mice, rats, chickens and other vertebrates, logic would suggest that there’s an equal case for regulations enforcing humane treatment of cephalopods.

Such rules generally specify that when a species is held in captivity, its housing conditions should support the animal’s welfare and natural behavior. This view has led some U.S. states to outlaw confined cages for egg-laying hens and crates too narrow for pregnant sows to turn around.

Animal welfare regulations say little about invertebrates, but guidelines for the care and use of captive cephalopods have started to appear over the past decade. In 2010, the European Union required considering ethical issues when using cephalopods for research. And in 2015, AAALAC International, an international accreditation organization for ethical animal research, and the Federation of European Laboratory Animal Science Associations promoted guidelines for the care and use of cephalopods in research. The U.S. National Institutes of Health is currently considering similar guidelines.

The “alien” minds of octopuses and their relatives are fascinating, not the least because they provide a mirror through which we can reflect on more familiar forms of intelligence. Deciding which species deserve moral consideration requires selecting criteria, such as neuron count or learning capacity, to inform those choices.

Once these criteria are set, it may be well to also consider how they apply to the rodents, birds and fish that occupy more familiar roles in our lives. Läs mer…

The Bob Dylan biopic “A Complete Unknown,” starring Timothée Chalamet, focuses on Dylan’s early 1960s transition from idiosyncratic singer of folk songs to internationally renowned singer-songwriter.

As a music historian, I’ve always respected one decision of Dylan’s in particular – one that kicked off the young artist’s most turbulent and significant period of creative activity.

Sixty years ago, on Halloween Night 1964, a 23-year-old Dylan took the stage at New York City’s Philharmonic Hall. He had become a star within the niche genre of revivalist folk music. But by 1964 Dylan was building a much larger fanbase through performing and recording his own songs.

Columbia Records was on hand to turn Dylan’s Oct. 31, 1964, performance into a live album.
GAB Archive/Redferns via Getty Images

Dylan presented a solo set, mixing material he had previously recorded with some new songs. Representatives from his label, Columbia Records, were on hand to record the concert, with the intent to release the live show as his fifth official album.

It would have been a logical successor to Dylan’s four other Columbia albums. With the exception of one track, “Corrina, Corrina,” those albums, taken together, featured exclusively solo acoustic performances.

But at the end of 1964, Columbia shelved the recording of the Philharmonic Hall concert. Dylan had decided that he wanted to make a different kind of music.

From Minnesota to Manhattan

Two-and-a-half years earlier, Dylan, then just 20 years old, started earning acclaim within New York City’s folk music community. At the time, the folk music revival was taking place in cities across the country, but Manhattan’s Greenwich Village was the movement’s beating heart.

Mingling with and drawing inspiration from other folk musicians, Dylan, who had recently moved to Manhattan from Minnesota, secured his first gig at Gerde’s Folk City on April 11, 1961. Dylan appeared in various other Greenwich Village music clubs, performing folk songs, ballads and blues. He aspired to become, like his hero Woody Guthrie, a self-contained artist who could employ vocals, guitar and harmonica to interpret the musical heritage of “the old, weird America,” an adage coined by critic Greil Marcus to describe Dylan’s early repertoire, which was composed of material learned from prewar songbooks, records and musicians.

While Dylan’s versions of older songs were undeniably captivating, he later acknowledged that some of his peers in the early 1960s folk music scene – specifically, Mike Seeger – were better at replicating traditional instrumental and vocal styles.

Dylan, however, realized he had an unrivaled facility for writing and performing new songs.

In October 1961, veteran talent scout John Hammond signed Dylan to record for Columbia. His eponymous debut, released in March 1962, featured interpretations of traditional ballads and blues, with just two original compositions. That album sold only 5,000 copies, leading some Columbia officials to refer to the Dylan contract as “Hammond’s Folly.”

Full steam ahead

Flipping the formula of its predecessor, Dylan’s 1963 follow-up album, “The Freewheelin’ Bob Dylan,” offered 11 originals by Dylan and just two traditional songs. The powerful collection combined songs about relationships with original protest songs, including his breakthrough “Blowin’ in the Wind.”

“The Times They Are A-Changin’,” his third release, exclusively showcased Dylan’s own compositions.

Dylan’s creative output continued. As he testified in “Restless Farewell,” the closing track for “The Times They Are A-Changin’,” “My feet are now fast / and point away from the past.”

Released just six months after “The Times,” Dylan’s fourth Columbia album, “Another Side of Bob Dylan,” featured solo acoustic recordings of original songs that were lyrically adventurous and less focused on current events. As suggested in his song “My Back Pages,” he was now rejecting the notion that he could – or should – speak for his generation.

Bringing it all together

By the end of 1964, Dylan yearned to break away permanently from the constraints of the folk genre – and from the notion of “genre” altogether. He wanted to subvert the expectations of audiences and to rebel against music industry forces intent on pigeonholing him and his work.

The Philharmonic Hall concert went off without a hitch, but Dylan refused to let Columbia turn it into an album. The recording wouldn’t generate an official release for another four decades.

Instead, in January 1965, Dylan entered Columbia’s Studio A to record his fifth album, “Bringing It All Back Home.” But this time, he embraced the electric rock sound that had energized America in the wake of Beatlemania. That album introduced songs with stream-of-consciousness lyrics featuring surreal imagery, and on many of the songs Dylan performed with the accompaniment of a rock band.

Dylan plays a Fender Jazz bass while recording ‘Bringing It All Back Home’ in Columbia’s Studio A in New York City in January 1965.
Michael Ochs Archives/Getty Images

“Bringing It All Back Home,” released in March 1965, set the tone for Dylan’s next two albums: “Highway 61 Revisited,” in August 1965, and “Blonde and Blonde,” in June 1966. Critics and fans have long considered these latter three albums – pulsing with what the singer-songwriter himself called “that thin, that wild mercury sound” – as among the greatest albums of the rock era.

On July 25, 1965, at the Newport Folk Festival, Dylan invited members of the Paul Butterfield Blues Band on stage to accompany three songs. Since the genre expectations for folk music during that era involved acoustic instrumentation, the audience was unprepared for Dylan’s loud performances. Some critics deemed the set an act of heresy, an affront to folk music propriety. The next year, Dylan embarked on a tour of the U.K., and an audience member at the Manchester stop infamously heckled him for abandoning folk music, crying out, “Judas!”

Yet the creative risks undertaken by Dylan during this period inspired countless other musicians: rock acts such as the Beatles, the Animals and the Byrds; pop acts such as Stevie Wonder, Johnny Rivers and Sonny and Cher; and country singers such as Johnny Cash.

Acknowledging the bar that Dylan’s songwriting set, Cash, in his liner notes to Dylan’s 1969 album “Nashville Skyline,” wrote, “Here-in is a hell of a poet.”

Enlivened by Dylan’s example, many musicians went on to experiment with their own sound and style, while artists across a range of genres would pay homage to Dylan through performing and recording his songs.

In 2016, Dylan received the Nobel Prize in literature “for having created new poetic expressions within the great American song tradition.” His early exploration of this tradition can be heard on his first four Columbia albums – records that laid the groundwork for Dylan’s august career.

Back in 1964, Dylan was the talk of Greenwich Village.

But now, because he never rested on his laurels, he’s the toast of the world. Läs mer…

The total damage from Hurricane Helene to North Carolina – be it physical, psychological or economic – is difficult to quantify. But the numbers reported by the Office of State Budget and Management are harrowing: over 100 deaths, US$59.6 billion in damages and thousands of homes destroyed, as of Dec. 13, 2024.

More than two months after the storm struck land on Sep. 27, small businesses are still struggling to recover from the flooding and lost inventory. Families remain displaced, their homes laid to waste.

But natural disasters like hurricanes don’t just endanger homes and infrastructure. There are items at risk that might not have price tags attached to them, but nonetheless matter a great deal to survivors: family photographs, heirlooms, journals, letters and documents.

That’s where Leah Bright and Brian Michael Lione come in.

Bright is an objects conservator at the Smithsonian American Art Museum, where she’s responsible for the long-term preservation of the collection, including preventive care and repairs. Lione manages the International Cultural Heritage Protection Program at the Smithsonian’s Museum Conservation Institute, supporting disaster response globally, including in Iraq and the U.S.

A few weeks after the hurricane struck, they flew down to North Carolina to support the Federal Emergency Management Agency’s Save Your Family Treasures program, providing demonstrations and resources to survivors explaining how to salvage their damaged belongings.

In an interview, which has been edited for length and clarity, they describe their experiences on the ground, while relaying some simple steps that can be taken to better protect family heirlooms from natural disasters.

When did cultural preservation become a part of disaster preparedness?

Leah Bright: I think within the profession of conservation, the 1966 floods in Florence, Italy, represented a big moment that sparked the formulation of a lot of disaster response procedures. The floods caused severe damage to a lot of cultural institutions there, and conservators from all around the world went to help salvage affected heritage items like books and paintings.

In the wake of that event, there were a lot of papers and articles written about the best ways to respond to disasters with conservation and cultural heritage in mind.

Florence, Italy, experienced devastating flooding in 1966, damaging or destroying countless cultural artifacts.
Bettmann/Getty Images

Brian Michael Lione: In terms of the Smithsonian getting involved, I believe that goes back to the Haitian earthquake in 2010. Richard Kurin, who’s still at the Smithsonian, formed a team of people to respond directly to the disaster in Haiti. He deployed dozens of conservators to support recovery efforts in Haiti, at the request of the Haitian government.

Before then, I’d say it was much more ad hoc. A lot of federal agencies did this work, but they weren’t coordinated to the extent that they are today. Today the Smithsonian and FEMA currently co-sponsor the Heritage Emergency National Task Force – HENTF – which connects over 60 organizations, including several federal agencies.

This network is what allows us to get down to North Carolina, or to other disaster areas, and coordinate with government agencies.

How did your trip to North Carolina come together?

Bright: Representatives from the Smithsonian Cultural Rescue Initiative are in contact with FEMA and HENTF, which organize the Save Your Family Treasures program. They expressed a need for additional volunteers from the Smithsonian, so Smithsonian Cultural Rescue Initiative representatives reached out to Smithsonian staff who had completed the required training to see who was interested. We expressed interest. There was a little flurry of activity and logistical details. Soon enough, we landed in Charlotte.

Lione: We arrived on a Tuesday and went to a Joint Field Office. That’s the larger kind of disaster-level, disaster-wide command center. It’s where FEMA coordinates its larger scale efforts with state governments, local governments and other bodies. And then all of these disaster response centers, or DRCs, are set up in local communities to provide support to survivors. I think there were as many as 13 or 14 of them, and some would open and then close depending on need.

For example, one DRC was in a school in Asheville, but they wanted to reopen the school, so they asked FEMA to move out of the school and move into a temporary location. The second week we were there, that DRC was, I believe, in a tent. The DRCs were as close to the centers of need as possible. They’re typically easy for the public to access, so that means there’s a facility, parking and accessible roads. FEMA personnel primarily staff the DRCs.

So survivors will come in if they’ve started a request for FEMA assistance online or on the phone. They can continue it there in person with staffers. Or if they haven’t started, they can sit down and start that process. There were also state workers there and local government employees who could answer questions about aid.

Our program, Save Your Family Treasures, is set up in a way so that as the survivors come in and have questions about assistance, we can also hop in and offer advice and tips for how to salvage objects of importance. The initiative provides information on salvaging books, photographs, records, tapes, paintings, framed artwork, clothing and even furniture and leather to a lesser extent.

In the case of the hurricane, it was really about offering tips for how to save objects that are going to get wet. If they’re not addressed quickly, within a week or two, mold is going to set in, and some of these things could very easily become too far gone.

So you arrived a little over three weeks after the disaster had struck. What did it look like on the ground?

Bright: I had anticipated being placed in areas that had experienced widespread destruction, and figured we’d be working in these wastelands. But most of the locations where I was stationed appeared relatively normal. Occasionally, I noticed patches of trees that had been blown down or places where you could see the water level had risen – it was really muddy, or there would be water lines on buildings. But generally, in my experience, the Disaster Recovery Centers were in safe and easily accessible locations.

Lione: My first week, I was in a place called Old Fort. It was just east of Asheville, and it’s built along a stream bed. On I-40, you could see stains of mud on the road from the mud slides that the state had recently cleared away. That road had only been opened recently. Getting off of I-40 and into town, we crossed over two small bridges. That route was completely clear. There were piles of debris here and there, but they had prioritized getting the main roads open, the bridges open, the railroads open.

But a block or two off that main road, I saw several houses that had been knocked off their foundations, several that had been completely destroyed, and water lines high up on brick buildings. There were massive piles of debris everywhere, and people were parking on their lawns because their driveways were just piled high with stuff. Those big, electric highway construction signs were flashing messages about curfews.

Were there any interactions with survivors that stood out?

Bright: There was a wide range of reasons why people showed up to chat with us. Some people didn’t experience much damage at all, while others had entire homes that had been flooded or destroyed. Overall, I was really struck by both the range of damage, but also how everyone had an incredible amount of gratitude, even if they didn’t have much left to salvage.

One woman that I spoke with was so grateful to have come across our table because just that morning, she had put a lot of belongings out on the curb that she had assumed were irreparably damaged and had to be thrown away. But after we demonstrated how she might be able to salvage them, she rushed back home to try to save them.

We often recommend freezing photographs or books, since that can buy people time if they don’t have the bandwidth to deal with damaged belongings in the moment. People were usually surprised to learn that photographs that are stuck together can often be safely separated and preserved for the future.

There was a family who came in that had come across a big batch of photographs from a neighbor who lived a mile away, whose home had been swept away by the flood waters. They recognized who she was and were thrilled to be able to assist that person with salvaging her photographs.

Most people would come to our table with a little bit of skepticism. Some of them didn’t understand why we were there. It seemed like a fluffy kind of service in comparison to some of the more serious FEMA funding conversations taking place. But I could also sense the relief when survivors learned about the steps they could take to preserve their heirlooms. Survivors might feel powerless filling out seemingly endless paperwork and waiting to hear about available resources, so we worked to provide tangible steps survivors could take in the interim to bring them some much-needed hope.

Lione: We had instructions to send people away with. It was a lot of information to digest at once. So these handouts were helpful because they included very basic steps to save heirlooms – for example, for photographs: Get out three turkey trays and put distilled water in each of them. Let your photos soak for a while. They may pull apart. Simple instructions like that.

A handout with tips for preserving damaged photographs.
HENTF, FEMA and Smithsonian, CC BY-ND

These were tasks that these people could carry out on their own. So many of them had lost everything – their lives were out of control and completely upended. So I could sense some relief when they realized they could watch a demonstration, take some information and then head home – or what’s left of home – to do something right now, as opposed to wait for an inspector, wait for an adjuster or wait for a road crew.

A couple of moments stood out to me. We had one person come in and say, “I have an urn that got wet. What do I do with that?” That was a bit of a unique thing, and that’s not really a conservation question. However, I happen to know a funeral director back home, so I texted him and found out that urns with cremations that are of certain age or era are likely sealed in a bag. They might be sealed in two bags. And so we were able to provide some basic information for what they might do with the urn to see if it had been inundated before they opened it.

The other thing that really struck me was how many people said, “Oh, well, this has happened to me at least five times, probably more.” Or: “We moved here to be safe from hurricanes.” Or: “We’ve already lost everything, once or twice.”

Brian Lione leads a practice demonstration for salvaging photographs for two FEMA colleagues at a Disaster Response Center in Waynesville, N.C., on Nov. 1, 2024.
Photo courtesy of Brian Lione, CC BY-ND

So our role can also assume more of a preparedness element: If we assume it’s going to happen again, what can you do ahead of time? We offered advice about where to store your most treasured possessions and how to buy waterproof totes. We emphasized the importance of making copies of key documents and scanning and uploading them to the cloud. As heritage professionals, we do all of this with our collections.

The phrase “climate change” came up several times. No one turned their nose up at it. People were aware – particularly those who had moved to North Carolina to avoid hurricanes – that floods, high winds and strange weather patterns are probably the new normal. So they were able to take some of that preparedness information away with them and think, “OK, well, this is something important to know – not just to recover from this most recent disaster, but to prepare for the next one.” Läs mer…

More than one-third of all animals on Earth, from beetles to cows to elephants, depend on plant-based diets. Plants are a low-calorie food source, so it can be challenging for animals to consume enough energy to meet their needs. Now climate change is reducing the nutritional value of some foods that plant eaters rely on.

Human activities are increasing atmospheric carbon dioxide levels and raising global temperatures. As a result, many plants are growing faster across ecosystems worldwide.

Some studies suggest that this “greening of the Earth” could partially offset rising greenhouse gas emissions by storing more carbon in plants. However, there’s a trade-off: These fast-tracked plants can contain fewer nutrients per bite.

I’m an ecologist and work with colleagues to examine how nutrient dilution could affect species across the food web. Our focus is on responses in plant-feeding populations, from tiny grasshoppers to giant pandas.

We believe long-term changes in the nutritional value of plants may be an underappreciated cause of shrinking animal populations. These changes in plants aren’t visually evident, like rising seas. Nor are they sudden and imminent, like hurricanes or heat waves. But they can have important impacts over time.

Plant-eating animals may need more time to find and consume food if their usual meal becomes less nutritious, exposing themselves to greater risks from predators and other stresses in the process. Reduced nutritional values can also make animals less fit, reducing their ability to grow, reproduce and survive.

Rising carbon, falling nutrients

Research has already shown that climate change is causing nutrient dilution in human food crops. Declines in micronutrients, which play important roles in growth and health, are a particular concern: Long-term records of crop nutritional values have revealed declines in copper, magnesium, iron and zinc.

In particular, human deficiencies in iron, zinc and protein in particular are expected to increase in the coming decades because of rising carbon dioxide levels. These declines are expected to have broad impacts on human health and even survival, with the strongest effects among populations that are highly dependent on rice and wheat, such as in East and Central Asia.

Grass tissue from a tallgrass prairie in Kansas shows nutrient levels in the plant falling as the plant grows from May through September.
Kaspari and Welti, 2024, CC BY-ND

The nutritional value of livestock feed is also declining. Cattle spend a lot of time eating and often have a hard time finding enough protein to meet their needs. Protein concentrations are falling in grasses across rangelands around the world. This trend threatens both livestock and ranchers, reducing animals’ weight gains and costing producers money.

Nutrient dilution affects wild species too. Here are some examples.

Dependent on bamboo

Giant pandas are a threatened species with great cultural value. Because they reproduce at low rates and need large, connected swaths of bamboo as habitat, they are classified as a vulnerable species whose survival is threatened by land conversion for farming and development. Pandas also could become a poster animal for the threat of nutrient dilution.

The giant panda is considered an “umbrella species,” which means that conserving panda habitat benefits many other animals and plants that also live in bamboo groves. Famously, giant pandas are entirely dependent on bamboo and spend large portions of their days eating it. Now, rising temperatures are reducing bamboo’s nutritional value and making it harder for the plant to survive.

Giant pandas spend 10 to 14 hours a day or more eating bamboo, a giant grass species.

Mixed prospects for insects

Insects are essential members of the web of life that pollinate many flowering plants, serve as a food source for birds and animals, and perform other important ecological services. Around the world, many insect species are declining in developed areas, where their habitat has been converted to farms or cities, as well as in natural areas.

In zones that are less affected by human activity, evidence suggests that changes in plant chemistry may play a role in decreasing insect numbers.

Many insects are plant feeders that are likely to be affected by reduced plant nutritional value. Experiments have found that when carbon dioxide levels increase, insect populations decline, at least partly due to lower-quality food supplies.

Not all insect species are declining, however, and not all plant-feeding insects respond in the same way to nutrient dilution. Insects that chew leaves, such as grasshoppers and caterpillars, suffer the most negative effects, including reduced reproduction and smaller body sizes.

In contrast, locusts prefer carbon-rich plants, so rising carbon dioxide levels could cause increases in locust outbreaks. Some insects, including aphids and cicadas, feed on phloem – the living tissue inside plants that carries food made in the leaves to other parts of the plant – and may also benefit from carbon-rich plants.

Uneven impacts

Declines in plant food quality are most likely to affect places where nutrients already are scarce and animals struggle now to meet their nutritional needs. These zones include the ancient soils of Australia, along with tropical areas such as the Amazon and Congo basins. Nutrient dilution is also an issue in the open ocean, where rapidly warming waters are reducing the nutritional content of giant sea kelp.

Certain types of plant-feeding animals are likely to face greater declines because they need higher-quality food. Rodents, rabbits, koalas, horses, rhinoceroses and elephants are all hind-gut fermenters – animals that have simple, single-chambered stomachs and rely on microbes in their intestines to extract nutrients from high-fiber food.

Grazers like these endangered Grevy’s zebras in Kenya need higher-quality food than ruminants such as cattle.
Wolfgang Kaehler/LightRocket via Getty Images

These species need more nutrient-dense food than ruminants – grazers like cattle, sheep, goats and bison, with four-chambered stomachs that digest their food in stages. Smaller animals also typically require more nutrient-dense food than larger ones, because they have faster metabolisms and consume more energy per unit of body mass. Smaller animals also have shorter guts, so they can’t as easily extract all the nutrients from food.

More research is needed to understand what role nutrient dilution may be playing in declines of individual species, including experiments that artificially increase carbon dioxide levels and studies that monitor long-term changes in plant chemistry alongside animals in the field.

Over the longer term, it will be important to understand how nutrient dilution is altering entire food webs, including shifts in plant species and traits, effects on other animal groups such as predators, and changes in species interactions. Changes in plant nutritional value as a result of rising carbon dioxide levels could have far-reaching impacts throughout ecosystems worldwide. Läs mer…

If you have visited an island like one of the Hawaiian Islands, Tahiti or Easter Island, also known as Rapa Nui, you may have noticed how small these land masses appear against the vast Pacific Ocean. If you’re on Hawaii, the nearest island to you is more than 1,000 miles (1,600 kilometers) away, and the coast of the continental United States is more than 2,000 miles (3,200 kilometers) away. To say these islands are secluded is an understatement.

For me, watching the movie “Moana” in 2016 was eye-opening. I knew that Polynesian people traveled between a number of Pacific islands, but seeing Moana set sail on a canoe made me realize exactly how small those boats are compared with what must have seemed like an endless ocean. Yet our fictional hero went on this journey anyway, like the countless real-life Polynesian voyagers upon which she is based.

Islands in Polynesia can be thousands of miles apart.
NASA

As an astronomer, I have been teaching college students and visitors to our planetarium how to find stars in our sky for more than 20 years. As part of teaching appreciation for the beauty of the sky and the stars, I want to help people understand that if you know the stars well, you can never get lost.

U.S. Navy veterans learned the stars in their navigation courses, and European cultures used the stars to navigate, but the techniques of Polynesian wayfinding shown in Moana brought these ideas to a very wide audience.

The movie Moana gave me a new hook – pun not intended – for my planetarium shows and lessons on how to locate objects in the night sky. With “Moana 2” out now, I am excited to see even more astronomy on the big screen and to figure out how I can build new lessons using the ideas in the movie.

The North Star

Have you ever found the North Star, Polaris, in your sky? I try to spot it every time I am out observing, and I teach visitors at my shows to use the “pointer stars” in the bowl of the Big Dipper to find it. These two stars in the Big Dipper point you directly to Polaris.

In the northern sky, you can follow the ‘pointer stars’ in Ursa Major/The Big Dipper – shown here with a pink arrow – to a star in a pink circle, which is Polaris, or the North Star.
Starry Night Enthusiast/Christopher Palma

If you are facing Polaris, then you know you are facing north. Polaris is special because it is almost directly above Earth’s North Pole, and so everyone north of the equator can see it year-round in exactly the same spot in their sky.

It’s a key star for navigation because if you measure its height above your horizon, that tells you how far you are north of Earth’s equator. For the large number of people who live near 40 degrees north of the equator, you will see Polaris about 40 degrees above your horizon.

If you live in northern Canada, Polaris will appear higher in your sky, and if you live closer to the equator, Polaris will appear closer to the horizon. The other stars and constellations come and go with the seasons, though, so what you see opposite Polaris in the sky will change every month.

Look for the Big Dipper to find the North Star, Polaris.

You can use all of the stars to navigate, but to do that you need to know where to find them on every night of the year and at every hour of the night. So, navigating with stars other than Polaris is more complicated to learn.

Maui’s fishhook

At the end of June, around 11 p.m., a bright red star might catch your eye if you look directly opposite from Polaris. This is the star Antares, and it is the brightest star in the constellation Scorpius, the Scorpion.

If you are a “Moana” fan like me and the others in my family, though, you may know this group of stars by a different name – Maui’s fishhook.

If you are in the Northern Hemisphere, Scorpius may not fully appear above your horizon, but if you are on a Polynesian island, you should see all of the constellation rising in the southeast, hitting its highest point in the sky when it is due south, and setting in the southwest.

Scorpius, which is referred to as Maui’s fishhook by Hawaiians, is a constellation shown here in the southern sky.
Starry Night Enthusiast/Christopher Palma

Astronomers and navigators can measure latitude using the height of the stars, which Maui and Moana did in the movie using their hands as measuring tools.

The easiest way to do this is to figure out how high Polaris is above your horizon. If you can’t see it at all, you must be south of the equator, but if you see Polaris 5 degrees (the width of three fingers at arm’s length) or 10 degrees above your horizon (the width of your full fist held at arm’s length), then you are 5 degrees or 10 degrees north of the equator.

The other stars, like those in Maui’s fishhook, will appear to rise, set and hit their highest point at different locations in the sky depending on where you are on the Earth.

Polynesian navigators memorized where these stars would appear in the sky from the different islands they sailed between, and so by looking for those stars in the sky at night, they could determine which direction to sail and for how long to travel across the ocean.

Today, most people just pull out their phones and use the built-in GPS as a guide. Ever since “Moana” was in theaters, I see a completely different reaction to my planetarium talks about using the stars for navigation. By accurately showing how Polynesian navigators used the stars to sail across the ocean, Moana helps even those of us who have never sailed at night to understand the methods of celestial navigation.

The first “Moana” movie came out when my son was 3 years old, and he took an instant liking to the songs, the story and the scenery. There are many jokes about parents who dread having to watch a child’s favorite over and over again, but in my case, I fell in love with the movie too.

Since then, I have wanted to thank the storytellers who made this movie for being so careful to show the astronomy of navigation correctly. I also appreciated that they showed how Polynesian voyagers used the stars and other clues, such as ocean currents, to sail across the huge Pacific Ocean and land safely on a very small island thousands of miles from their home. Läs mer…

The water that makes up the oceans acted as a key ingredient for the development of life on Earth. However, scientists still do not know where the water here on Earth came from in the first place.

One leading idea is that space rocks such as comets and asteroids delivered water to the Earth through impacts. As a planetary scientist, I’m curious about the kinds of space objects that could have led to the formation of the oceans. For the past few years, I’ve been studying a type of object that I called a dark comet – which could be just the culprit. In a new study my colleagues and I published in December 2024, we discovered two classes of these elusive dark comets

Dark comets fly through space, but unlike comets, they don’t have dust tails.
Adina Feinstein and NASA’s Earth Observatory

What is a comet?

The solar system is teaming with small bodies such as comets and asteroids. These space rocks were fundamental building blocks of planets in the early solar system, while the remaining leftovers are the comets and asteroids seen today.

These objects are also avenues by which material can be transported throughout the solar system. These small worlds can contain things such as rubble, ice and organic material as they fly through space. That’s why researchers see them as good potential candidates for delivering ices such as water and carbon dioxide to the Earth while it was forming.

Traditionally, the difference between comets and asteroids is that comets have beautiful cometary tails. These tails form because comets have ice in them, while asteroids supposedly do not.

When a comet gets close to the Sun, these ices heat up and sublimate, which means they turn from ice into gas. The gas heats up because of the sunlight and is then blown off the comet’s surface in a process called outgassing. This outgassing brings with it rubble and small dust grains, which reflect sunlight.

Asteroids, on the other hand, do not have cometary tails. Presumably, they are more like classic rocks – without ice on their surfaces.

What is a nongravitational acceleration?

The outgassing material from the surface of a comet produces a cometary tail and a rocketlike recoil. The fast moving gas pushes on the surface of the comet, and this causes it to accelerate. This process drives comets’ motion through space on top of the motion set by the gravitational pull of the Sun.

So, when comets outgas, they have what planetary scientists call nongravitational acceleration – motion that isn’t caused by the gravity of objects in the solar system. Planetary scientists typically measure the nongravitational accelerations of comets after detecting their cometary tails.

What are dark comets?

Our team identified a class of small bodies in the solar system that take some of the properties of both comets and asteroids. We called them dark comets.

These dark comets have nongravitational accelerations like comets, so they experience a rocketlike recoil from comet outgassing. However, they don’t have the dusty tails that most comets have.

In other words, they look like typical asteroids, but gravity alone can’t explain their motion.

The first interstellar object, ’Oumuamua, was the first comet or asteroid-size body that was detected in the solar system that came from outside of the solar system.

’Oumuamua displayed this same mysterious combination of no dust tail but a cometlike nongravitational acceleration, which led to many theories trying to explain what the object could have been. One option is that it was outgassing like a comet but not producing a dusty tail.

Since ’Oumuamua was first spotted in 2017, my colleagues and I have identified other dark comets within the solar system. In our study, we found seven new dark comets, bringing the total to 14.

Now that we’ve found more dark comets, we’ve noticed that they come in two flavors. Outer dark comets are larger – about a mile wide in size – and on more elliptical orbits farther out in the solar system. Inner dark comets are smaller – typically 1,000 feet in size – and on circular orbits close to the Earth.

Outer dark comets, shown in red, have longer orbits than inner dark comets, shown in gray.
Darryl Seligman

Contributions to the Earth’s oceans?

It’s still not clear exactly what these dark comets are. They may not even be traditional comets if they don’t have icy surfaces.

However, the most likely answer for their nongravitational accelerations is that they outgas water, like a comet, but don’t produce a dusty tail – at least not one we can see when we look at them with our telescopes.

If this is the case, there are sure to be many more of these objects, parading around like asteroids, still yet to be identified.

Since scientists don’t know for sure where the Earth’s water came from, if there really are lots of dark comets that have water near Earth, it is possible that these dark comets contributed water to the early Earth.

These dark comets could tell researchers more about the origins of Earth’s oceans and the development of life here on Earth.

Reasons to be excited for the future

This research is really just the tip of the iceberg, because we only just started finding these dark comets in 2023.

The Vera C. Rubin Observatory’s Legacy Survey of Space and Time, which comes online in 2025, will start scanning the entire southern sky almost every night to spot anything that moves. This telescope, located on a mountain in Chile’s Atacama desert, is home to the largest camera ever built.

It will give astronomers almost five orders of magnitude greater sensitivity for detecting moving objects in the night sky. It will likely help my colleagues and me discover lots of new dark comets in the near future.

Telescopes that are already operating, such as the Hubble Space Telescope and the James Webb Space Telescope, could also help my team watch for outgassing or ice on the surface of the 14 dark comets we’ve already identified.

Landing on a dark comet would probably look similar to Hayabusa2’s rendezvous with the Ryugu asteroid.

Finally, the JAXA Hayabusa2 extended mission is slated to rendezvous with one of the inner dark comets, 1998 KY26, in 2031. Therefore, we will be able to see the surface of a dark comet in exquisite detail. Läs mer…