Friday briefing: ​Have we found ​signs of ​life elsewhere in the cosmos?

The Guardian

18-04-2025

Good morning.
The very real uptick in the intrigue around UFOs and alien life in recent years makes sense when you find out that such increased interest often occurs during economic downturns like recessions (yes, really). But this time there are no grainy images of some indistinct streak across the sky. Instead the latest in the question of whether we are truly alone in the universe comes from eminent astronomers.
This week it was announced that astronomers at the University of Cambridge used the James Webb space telescope to observe a planet called K2-18 b, which appeared to show the chemical signatures of two compounds that on Earth are only known to be produced by living organisms.
To be clear, this is not a discovery of alien life. As with much scientific research, it is a complex (and contested) observation about a planet that is 700 trillion miles away – and the clues point to something called 'marine phytoplankton', which are not exactly giant arachnid warlords with laser cannon.
For today's newsletter I spoke with the Guardian's science editor, Ian Sample, about what the scientists found and how significant it all is. That's right after the headlines.
Transport | An inquest into the deaths of four people killed by drivers with failing eyesight in northern England has found enforcement of visual legal standards for motorists is 'ineffective and unsafe'. The HM senior coroner for Lancashire, Dr James Adeley, has sent a report to the transport secretary, Heidi Alexander, calling for action to be taken to prevent future deaths.
US news | Luigi Mangione was indicted on Thursday on a federal murder charge in the killing of UnitedHealthcare chief executive Brian Thompson outside a Manhattan hotel last year, a necessary step for prosecutors to seek the death penalty.
Yemen | US airstrikes on Yemen's Houthi rebels killed 33 people and wounded 80 others, Houthi-run media said early on Friday. If confirmed, it would mark one of the deadliest days of a campaign launched under Donald Trump that has involved hundreds of strikes since 15 March.
Gender | Updated guidance for public bodies is expected to be issued by the summer after the UK supreme court's ruling that a woman is defined in law by biological sex, the head of the equalities regulator said on Thursday.
Politics | Labour ministers are scrambling to avoid a damaging rebellion this summer when MPs vote on controversial cuts to disability benefit payments, even offering potential rebels the chance to miss the vote altogether. The government is due to hold a vote in June and dozens of its MPs are worried it will hurt their constituents and could cost them their seats
K2-18 b, which is approximately 2.6 times the radius of Earth, sits 124 light years away in the constellation of Leo. If you're keen to spot it, you can. 'If you locate the Big Dipper, there are two stars that form the far side of the pan. If you follow those downwards, you'll come to a sort of reversed question mark – and that is part of the constellation of Leo,' Ian says.
The planet orbits within the habitable zone of its star, a cool red dwarf less than half the size of the Sun. When the Hubble space telescope appeared to detect water vapour in its atmosphere in 2019, scientists hailed it as 'the most habitable known world' beyond our solar system.
What did the scientists find this time?
There is no way for people to photograph or reach planets beyond our solar system. However, scientists can investigate and assess their properties, including chemical composition using the James Webb telescope. It is so powerful that it can track the chemical signatures of K2-18 b by observing the planet's transit as it passes in front of its host star, measuring the starlight that has been filtered through its atmosphere. 'All molecules absorb light at a particular wavelength, and you can use that as a chemical signature for that molecule in the atmosphere of another planet,' Ian explains. 'So in this case, scientists found that the atmosphere of K2-18 b contains a lot of dimethyl sulfide [DMS] and dimethyl disulfide [DMDS].'
These two compounds are why so many scientists are excited. On Earth they are only produced naturally by living organisms, specifically marine phytoplankton. There is no natural process on Earth that produces these molecules otherwise.
Is this a big deal?
'There's no doubt this is cool and a really interesting detection … but there is a but,' Ian says.
Sceptical scientists have queried the findings and what they reveal, pointing out that there is still some debate about the conditions of K2-18 b. 'The team in Cambridge think there's a vast water based ocean there, but others will argue that the data suggests the oceans on this planet are made of magma or that it is a gas planet, which obviously isn't particularly conducive to life as we know it,' Ian says.
A few more years of measurement are required to say more confidently that the astronomers are sure of these two compounds in the atmosphere. But there is also a possibility that, even if astronomers confirm robustly that DMS and DMDS are in the atmosphere of this planet, they may be created by unfamiliar chemical processes that do not involve life.
There is no way to go to the planet to see for ourselves, of course, but Prof Nikku Madhusudhan, who led the observations, told Hannah Devlin this has not been a barrier to the discovery of black holes or other cosmic phenomena. 'In astronomy the question is never about going there,' he said. 'We're trying to establish if the laws of biology are universal in nature. I don't see it as 'We have to go and swim in the water to catch the fish'.'
What kind of life are we talking about?
If and when those debates are settled, the kind of life we are talking about here is not little green three-eyed men or giant tentacled beings. K2-18 b, and planets like it, are not expected to host intelligent alien life, but more likely tiny microbes similar to those that lived in Earth's oceans billions of years ago.
For intelligent life to exist, there would presumably need to be a long period of stable environmental conditions for evolution to take place. 'With microbes, the requirement is lower,' Ian says.
Detecting signs of intelligent life might not involve biology and biosignatures at all. 'You would be looking for what they call technosignatures, which would be a form of radio or electromagnetic waves,' Ian says. 'They may be so advanced that they're way ahead of using those kinds of technologies but that's another thing to think about.'
What now?
Conducting this kind of research requires long-term, reliable funding. The James Webb space telescope took three decades to build, with an initial price tag of $10.8bn, which includes $861m set aside to support five years of operations.
Nasa has been experiencing funding cuts set out by the Trump administration and the team overseeing the telescope could face budget cuts of up to 20%, affecting every aspect of the flagship observatory's operations.
'If you start dismantling, undermining, sacking, redirecting research at a whim, you will completely destabilise all the work, and there is no doubt that cuts in the US will have a global impact because the US is such a dominant player in science,' Ian says. Even the feeling of uncertainty alone can have a chilling effect on research. 'One scientist in the US told me that this could set US science back a couple of decades.'
Her book (Who wants Normal?) is out today and here Frances Ryan shines a light on the growing number of young women in Britain who are disabled. Katy Vans, newsletters team
There is a familiar image of preppers: paranoid, conspiratorial, and typically rightwing. But that is starting to change, writes Aaron Gell, as a growing number of liberals begin to hunker down and get ready for Armageddon. Nimo
The new Tom Cruise? I personally would watch anything with Florence Pugh in it but the marketers for her new film Thunderbolts* are relying on the audience's desire to watch her do terrifying stunts. Katy
After many organisations bowed to the Trump administration's demands, Robert Reich highlights three institutions and countries that have pushed back against the White House's ever-growing ambitions for control and power. Nimo
More than 75% of Britons say they are frustrated with poor customer service – but has it gotten worse? Anna Tims reflects on how and why it has become so bad. Katy
Football | Manchester United scored three goals in seven extra-time minutes to complete a dramatic 5-4 win over Lyon – 7-6 on aggregate – and advance to the semi-finals of the Europa League. Oihan Sancet's penalty and Nico Williams's header earned Athletic Bilbao a 2-0 second-leg win to knock Rangers out of the Europa League. Dominic Solanke's 43rd-minute penalty was enough to give Tottenham a 1-0 win at Eintracht Frankfurt and a 2-1 victory on aggregate. Reece James suggested Chelsea had 'disrespected' the Conference League after suffering a shock 2-1 defeat to Legia Warsaw as they edged into the semi-finals.
Sign up to First Edition
Our morning email breaks down the key stories of the day, telling you what's happening and why it matters
after newsletter promotion
Rugby union | Johnny Sexton has been added to the British & Irish Lions coaching staff for the summer tour of Australia in a surprise move that raises further intrigue over the fly-half selection debate after his previous criticism of Finn Russell and endorsement of Owen Farrell.
Football | Virgil van Dijk has said there was never any doubt in his mind about staying at Liverpool after he signed a new two-year contract worth up to £400,000 a week. The Liverpool captain followed Mohamed Salah in committing his future to Anfield until 2027.
'Ministers scramble to stop Labour rebellion on disability benefit cuts' is the Guardian's splash. The i has 'UK under 'huge pressure' to cut food standards to win America deal'. Thought we already had these but the Express reports 'Revolutionary weight loss pill on way'. ''Third spaces' could be needed for trans people' says the Times and 'Labour turmoil on trans ruling' is the Mail's take, while the Telegraph's angle is 'UK's biggest bank vows 'solidarity' with trans workers'. 'It's time' – the Mirror reports on a couple's last moments before the husband's assisted death at Dignitas.
Our critics' roundup of the best things to watch, read, play and listen to right now
TVJust Act Normal | ★★★★★The BBC's new six-part comedy drama Just Act Normal is the creation of Janice Okoh, based on her 2011 play Three Birds. With their mother gone, three children are trying to fly under the radar of the authorities until the oldest, Tiana (Chenée Taylor), turns 18 and can officially look after them all. It's beautifully structured and holds its many strands in perfect tension. Okoh's work is done full justice by three extraordinary young actors – we are surely watching stars being born – and just as strong a supporting cast. It is altogether a wonderful thing. Lucy Mangan
Music
Julien Baker and Torres: Send a Prayer My Way | ★★★★☆The partnership between US singer-songwriters Mackenzie 'Torres' Scott and Julien Baker germinated in 2016. Nevertheless, it still feels telling that Send a Prayer My Way arrives now. Baker has spent much of the 2020s as one-third of Boygenius, a collaboration with Lucy Dacus and Phoebe Bridgers that spiralled into something that resembled a genuine pop phenomenon. Send a Prayer My Way, however, feels like a deliberate shift towards something more intimate and, perhaps, manageable. This is not the kind of 21st-century country that arrives, metaphorically, sporting a pink sequined cowboy hat. It's an album that seems intent on doing things its own way, regardless of commercial expectation or trends of the genre – a reminder that understated pleasures are pleasures all the same. Alexis Petridis
Film
Sinners | ★★★☆☆This gonzo horror-thriller mashup from Black Panther's Ryan Coogler is a freaky tale of supernatural evil and the blues that indirectly takes its inspiration from the legend of Mississippi bluesman Robert Johnson selling his soul to the devil at a remote crossroads in return for fame and fortune. In some ways, this is a black version of Robert Rodriguez's 90s head-trip From Dusk Till Dawn, but that isn't exactly how Coogler plays this film tonally. For the first half, it is pretty much a realistic period adventure in which outlaw anti-heroism functions in a believable world. And then the real demons show up. Peter Bradshaw
Game
Blue Prince (PC, PlayStation 5, Xbox) | ★★★★★In a similar style to What Remains of Edith Finch or Gone Home, Blue Prince has you exploring your character's atmospherically uninhabited family home. The point? Ostensibly, to fulfil the stipulation laid out in a deceased great uncle's will to find an elusive 46th room and thereby inherit the estate. But like a parfait dessert, this game is deliciously layered. Blue Prince sets a gently rewarding pace, the randomisation nudging you to try new things and make new discoveries each day. Naturally a magical mansion like this has a story; it's this, the family behind it, and the fantastical wider world in which they live, that will draw you to the 46th room and far, far beyond. Jordan Erica Webber
Is the gym gen Z's pub?
While generation Z are making gains at the gym, are they losing out on connection?
A bit of good news to remind you that the world's not all bad
In the 100 years since Mesonychoteuthis hamiltoni – that's the colossal squid to you, me and its mother – was identified, it had never once been caught on film in its natural habitat. Until now.
In the centennial year of its formal naming, footage of the heaviest invertebrate on the planet has finally been captured by an international team of scientists and researchers near the South Sandwich Islands in the south Atlantic Ocean.
The footage belies the creature's true size, however: rather than witnessing an adult, which can grow up to 23ft (seven metres) long and weigh up to half a tonne, the crew's subject was a mere baby at 11.8in (30cm).
'These unforgettable moments continue to remind us that the ocean is brimming with mysteries yet to be solved,' said Dr Jyotika Virmani, Schmidt Ocean Institute's executive director.
Sign up here for a weekly roundup of The Upside, sent to you every Sunday
And finally, the Guardian's puzzles are here to keep you entertained throughout the day. Until tomorrow.
Quick crossword
Cryptic crossword
Wordiply