Latest news with #exoplanets
Forbes
a day ago
- General
- Forbes
Scientists: Webb Telescope May Find Planet Around Closest Bright Star
Alpha Centauri, one of the two "Pointer Stars" that help stargazers find the Southern Cross in the ... More Southern Hemisphere, may have a planet in orbit around it. If it does, the Webb Telescope will find it — as long as it's Jupiter-sized. The closest star to the sun, Proxima Centauri, has a planet. It may even have two planets. Proxima Centauri is located in the constellation Centaurus, visible only from the southern hemisphere, but it's a red dwarf star too small to be seen. That brightest star in Centaurus — and the third brightest in the entire night sky — is Alpha Centauri. It's two stars (Alpha Centauri A and Alpha Centauri B) orbiting each other, with Proxima Centauri orbiting them every 550,000 years, in a weird-sounding (but not rare) three-star solar system. Does Alpha Centauri have planets around it? It's a Holy Grail among planet-hunters, mostly because Alpha Centauri is only 4.37 light-years distant. Since it's so close to the solar system, it's theoretically an ideal target for astrometry (the study of the movements of stars and celestial bodies), as well as for direct infrared imaging using the James Webb Space Telescope, two techniques that can detect planets orbiting distant stars — exoplanets. A new paper published this week in Research Notes of the American Astronomical Society details the use of the Webb telescope to study Alpha Centauri in February 2025. Although it didn't detect any planets, it provides glimpses of what may still be hiding around the star. The Alpha Centauri star system — a triple-star planetary system. According to the paper, the Webb telescope's Mid-InfraRed Instrument would have detected gas giant planets like Jupiter at about twice the Earth-sun distance from Alpha Centauri A if they were roughly similar to Earth's temperature. It's tricky because, in a system with two bright stars, light pollution is always a problem. Although the Webb telescope has a coronagraph disc to block the light from the host star (by creating an artificial eclipse) to help it detect planets in the vicinity, it doesn't have two coronagraphs to use on two separate stars. Despite that — and despite Alpha Centauri Ac being five billion years old, meaning any planets in its orbit would likely be very old, cool and therefore dim — the scientists think the Webb telescope can still be used to find large Jupiter-sized planets in its orbit. The authors call Alpha Centauri "an exceptional but challenging target for exoplanet searches." This early conclusion is based on just one set of observations from February 2025. Webb also observed Alpha Centauri A in August 2024 and April 2025, so more conclusions — and possibly a discovery of a planet — could be imminent. Illustration of the Earth-like exoplanet Proxima Centauri b orbiting the star Proxima Centauri. ... More (Illustration by Tobias Roetsch/Future Publishing via Getty Images) In 2016, astronomers found an exoplanet in Proxima Centauri's habitable zone and named it Proxima Centauri b. This exoplanet orbits its star every 11 days from just 5% of the Earth-sun distance from the star. Proxima Centauri b is thought to orbit the star's 'habitable zone,' which is defined as a distance that allows temperatures to be warm enough for liquid water to pool on the planet's surface. However, it's thought that Proxima Centauri sometimes unleashes a massive stellar flare — an energetic explosion of high energy radiation — that would make life as we know it impossible on any planets in orbit. A paper in 2020 suggested that Proxima Centauri may be orbited by a second "super-Earth" sized planet (bigger than Earth, but smaller than Uranus) about the same distance from its star as Mars is from the sun. If it exists, it orbits Proxima Centauri every 5.2 Earth years. Barnard's star is one of the fastest-moving stars in the night sky because it's just six light-years from the solar system. In October 2024, scientists unveiled a planet around it thought to be about half the size of Venus. Called Barnard's b, it's around 20 times closer than Mercury is to the sun. Wishing you clear skies and wide eyes.
The Independent
3 days ago
- General
- The Independent
The truth is out there? Why the scientific community struggles to accept ‘proof' of alien life
The search for extraterrestrial life has long gone back and forth between scientific curiosity, public fascination and outright scepticism. Recently, scientists claimed the 'strongest evidence' of life on a distant exoplanet – a world outside our solar system. Grandiose headlines often promise proof that we are not alone, but scientists remain cautious. Is this caution unique to the field of astrobiology? In truth, major scientific breakthroughs are rarely accepted quickly. Newton's laws of motion and gravity, Wegener's theory of plate tectonics, and human-made climate change all faced prolonged scrutiny before achieving consensus. But does the nature of the search for extraterrestrial life mean that extraordinary claims require even more extraordinary evidence? We've seen groundbreaking evidence in this search beforehand, from claims of biosignatures (potential signs of life) in Venus's atmosphere to Nasa rovers finding 'leopard spots' – a potential sign of past microbial activity – in a Martian rock. Both stories generated a public buzz around the idea that we might be one step closer to finding alien life. But on further inspection, abiotic (non-biological) processes or false detection became more likely explanations. In the case of the exoplanet, K2-18 b, scientists working with data from the James Webb Space Telescope (JWST) announced the detection of gases in the planet's atmosphere – methane, carbon dioxide, and more importantly, two compounds called dimethyl sulphide (DMS) and dimethyl disulphide (DMDS). As far as we know, on Earth, DMS/DMDS are produced exclusively by living organisms. Their presence, if accurately confirmed in abundance, would suggest microbial life. The researchers even suggest there's a 99.4% probability that the detection of these compounds wasn't a fluke – a figure that, with repeat observations, could reach the gold standard for statistical certainty in the sciences. This is a figure known as five sigma, which equates to about a one in a million chance that the findings are a fluke. So why hasn't the scientific community declared this the discovery of alien life? The answer lies in the difference between detection and attribution, and in the nature of evidence itself. JWST doesn't directly 'see' molecules. Instead, it measures the way that light passes through or bounces off a planet's atmosphere. Different molecules absorb light in different ways, and by analysing these absorption patterns – called spectra – scientists infer what chemicals are likely to be present. This is an impressive and sophisticated method – but also an imperfect one. It relies on complex models that assume we understand the biological reactions and atmospheric conditions of a planet 120 light years away. The spectra suggesting the existence of DMS/DMDS may be detected because you cannot explain the spectrum without the molecule you've predicted, but it could also result from an undiscovered or misunderstood molecule instead. Climate comparison Given how momentous the conclusive discovery of extraterrestrial life would be, these assumptions mean that many scientists err on the side of caution. But is this the same for other kinds of science? Let's compare with another scientific breakthrough: the detection and attribution of human-made climate change. The relationship between temperature and increases in CO₂ was first observed by the Swedish scientist Svante Arrhenius in 1927. It was only taken seriously once we began to routinely measure temperature increases. But our atmosphere has many processes that feed CO₂ in and out, many of which are natural. So the relationship between atmospheric CO₂ and temperature may have been validated, but the attribution still needed to follow. Carbon has three so-called flavours, known as isotopes. One of these isotopes, carbon-14, is radioactive and decays slowly. When scientists observed an increase in atmospheric carbon dioxide but a low volume of carbon-14, they could deduce that the carbon was very old – too old to have any carbon-14. Fossil fuels – coal, oil and natural gas – are composed of ancient carbon and thus are devoid of carbon-14. So the attribution of anthropogenic climate change was proven beyond reasonable doubt, with 97% acceptance among scientists. In the search for extraterrestrial life, much like climate change, there is a detection and attribution phase, which requires the robust testing of hypotheses and also rigorous scrutiny. In the case of climate change, we had in situ observations from many sources. This means roughly that we could observe these sources close up. The search for extraterrestrial life relies on repeated observations from the same sensors that are far away. In such situations, systematic errors are more costly. Further to this, both the chemistry of atmospheric climate change and fossil fuel emissions were validated with atmospheric tests under lab conditions from 1927 onwards. Much of the data we see touted as evidence for extraterrestrial life comes from light years away, via one instrument, and without any in situ samples. The search for extraterrestrial life is not held to a higher standard of scientific rigour, but it is constrained by an inability to independently detect and attribute multiple lines of evidence. For now, the claims about K2-18 b remain compelling but inconclusive. That doesn't mean we aren't making progress. Each new observation adds to a growing body of knowledge about the universe and our place in it. The search continues – not because we're too cautious, but because we are rightly so. Oliver Swainston is a Research Assistant at RAND Europe. Chris Carter is an Analyst on the Science and Emerging Technology Team at RAND Europe.
The Sun
25-05-2025
- Science
- The Sun
‘Beach resort' planet with '20C sea' could be future astro-tourist hotspot – but you may be DEAD by the time you arrive
THERE are planets beyond our own that could be hiding untouched paradises. Exoplanet LHS 1140 b is just one of them - and could make a great beach resort for astro-tourists of the future. 4 4 First unveiled in 2017, LHS 1140 b is 41 light-years away, and may be humanity's best chance of finding liquid water on a world outside our solar system. There's one pretty big hitch, however - anyone boarding a rocket destined for LHS 1140 b would likely die long before they arrived. If they don't, then they would probably be very old, and not quite up for the water sports that could be on the cards. Even the closest of exoplanets are too far away to visit. And although this world is relatively close to our own in cosmic terms, it would still take 41 years to get there - while travelling at the speed of light. Of course, we haven't yet mastered light speed travel - let alone anything faster. But with a possible ocean temperature of 20C (68F), this planet could host some epic beach days in a few millennia - if humans ever master interstellar travel. Last year, after falling under the James Webb Space Telescope 's keen eye, scientists were able to find out more about this distant world. They believe it is a potentially rocky world, much larger than Earth. Best-ever sign of ALIEN life found on distant planet as scientists '99.7% sure of astounding biological activity signal' It has a planet mass of 5.6 Earths and a year that lasts just 25 days, according to Nasa. Data gathered by JWST, the $10 billion telescope Nasa launched into space in 2021, strongly supports LHS 1140 b being an ocean world with a tentative nitrogen atmosphere. However, further observations are needed to fully confirm this. "Detecting an Earth-like atmosphere on a temperate planet is pushing Webb's capabilities to its limits; it's feasible; we just need lots of observing time,' René Doyon, of the International Research & Exchanges Board (iREx) who studied the data, said in a statement last year. 'The current hint of a nitrogen-rich atmosphere begs for confirmation with more data. 'We need at least one more year of observations to confirm that LHS 1140 b has an atmosphere, and likely two or three more to detect carbon dioxide." 4 LHS 1140 b is a super Earth exoplanet that lies in the so-called 'Goldilocks zone' of its nearest star. This is the area around a star where it's neither too hot nor too cold for a world to host liquid water. When the data was pinged back to Earth - a process that miraculously only takes about five seconds - it was the 'first time [scientists] have ever seen a hint of an atmosphere on a habitable zone rocky or ice-rich exoplanet," according to Ryan MacDonald, a Nasa Sagan Fellow in the University of Michigan's Department of Astronomy, who helped analyse LHS 1140 b's atmosphere. JWST data further suggests the exoplanet's mass might be made of between 10 and 20 per cent liquid water. While that could mean the planet looks like one big snowball - the side facing the sun could have a warm liquid ocean, making it look like an eyeball. Charles Cadieux, a doctoral student at the Université de Montréal and lead author of a paper on the discovery, said at the time: "Of all currently known temperate exoplanets, LHS 1140 b could well be our best bet to one day indirectly confirm liquid water on the surface of an alien world beyond our solar system. "This would be a major milestone in the search for potentially habitable exoplanets." 4
Yahoo
23-05-2025
- Science
- Yahoo
Astronomers want direct images of exoplanets. They may need 'quantum-level' tech to get them
When you buy through links on our articles, Future and its syndication partners may earn a commission. A team of scientists is developing a "quantum-sensitive" device that could capture direct images of Earth-like exoplanets — something astronomers tend to consider so difficult it's nearly impossible. Humanity's ability to image the heavens has improved by leaps and bounds since the invention of the telescope in 1608. Although the earliest of these images were far from clear, astronomers from generations ago could already observe craters on our moon, identify four of Jupiter's moons, and reveal a diffuse ribbon of light arching across the sky — what we now know represents the Milky Way's structure. But modern telescopes, like the James Webb Space Telescope (JWST), have really brought the field forward. For instance, telescopes these days rely on very sophisticated instruments called coronagraphs to observe light coming from objects orbiting bright stars. "Current leading coronagraphs, such as the vortex and PIAA coronagraphs, are ingenious designs," Nico Deshler, a Ph.D. student at the University of Arizona and co-author of the new study, told "A coronagraph is an instrument used in astronomy to block or suppress the light coming from a very bright object, like a star, to reveal fainter objects surrounding it." This allows scientists to detect objects more than a billion times fainter than the stars they orbit. However, Deshler and his colleagues believe they can push coronagraphs further to capture direct images of distant worlds. "Our team is broadly interested in the fundamental limits of sensing and metrology imposed by quantum mechanics, particularly in the context of imaging applications," Itay Ozer, a Ph.D. student at the University of Maryland and another of the study's co-authors, told The idea is to use principles of quantum mechanics to surpass the resolution limits of current telescopes, allowing scientists to image objects smaller or closer together than what traditional optics would permit. "The resolution of a telescope generally describes the smallest feature that the telescope can faithfully capture," said Ozer. "This smallest length scale, dubbed the 'diffraction limit,' is related to the wavelength of the detected light divided by the diameter of the telescope." This means gaining higher resolution requires building larger telescopes. However, launching a telescope large enough to surpass the diffraction limit necessary to directly image an exoplanet poses different types of challenges: high launch costs and extreme engineering complexity. "In this regard, developing sub-diffraction imaging methods is an important pursuit because it allows us to expand the domain of accessible exoplanets given the challenges and constraints associated with space-based observation," added Deshler. "We were inspired to explore the implications of these newfound quantum information-theoretic limits in the context of sub-diffraction exoplanet imaging where many Earth-like exoplanets are suspected to reside." The team thus designed a "quantum-level" coronagraph that can sort the light collected by a telescope and isolate the faint signal from exoplanets — light that is usually overwhelmed by the glare of their host stars. The concept relies on the fact that photons, or particles of light, travel in different patterns known as spatial modes. "In astronomical imaging, the position of each light source in the field of view of a telescope excites different optical spatial modes," explained Ozer. By using an optical device called a "spatial mode sorter," which is a cascade of carefully designed diffractive phase masks, the team was able to separate the incoming light, allowing them to isolate photons coming specifically from the exoplanet below the sub-diffraction limit. "As light interacts with each mask and propagates downstream through the mode sorter," said Deshler, "the optical field interferes with itself in such a way that the photons in each spatial mode get physically routed to different non-overlapping regions of space." "The correspondence between the positions of light sources and their corresponding excited spatial modes is central to […] nulling of starlight and detection of exoplanets," added Ozer. "In this way, we are able to siphon the photons emitted by the star away from the photons emitted by the exoplanet." This goes beyond digitally processing an image and subtracts starlight after the fact — in other words, it removes starlight in the optical domain before the light even reaches a detector. "In exoplanet searches, a telescope is rotated to point directly at a prospective star, which we model as a point source of light," explained Deshler. "Under this alignment between the star and the telescope axis, all the photons emanating from the star couple to the [telescope's] fundamental mode — the specific spatial mode that is excited when looking at an on-axis point source." Under this alignment, all the photons emanating from the star couple to the fundamental mode. By filtering out this mode, Deshler, Ozer and their colleagues were able to effectively eliminate the starlight, revealing only the light from the exoplanet. "The exoplanet's light is misaligned to the telescope axis, and excites a different spatial mode from the star,' said Ozer. "Our method preserves as much of the pristine uncontaminated photons from the exoplanet as possible, which turn out to carry all the available information." In the lab, the team set out to show that their device could detect exoplanets positioned extremely close to their host stars — closer than traditional resolution limits allow. They tested it using two points of light: a bright one to represent the star and a much dimmer one to simulate an exoplanet. By gradually moving the dimmer light and recording the resulting images, they assessed how well the device could localize the exoplanet. They found that when the artificial exoplanet was very close to the star — less than one-tenth the separation limit of current telescopes — most of its photons were filtered out along with the starlight. At larger separations, however, the exoplanet's signal became clearer, rising above background noise and aligning with theoretical predictions. Additionally, by setting the star to be 1,000 times brighter than the planet and analyzing the images with a maximum likelihood estimator, the team achieved results within a few percent of the theoretical limit across a wide range of sub-diffraction planet positions. "This is a proof-of-principle demonstration that spatial mode sorting coronagraphs may provide access to deeply sub-diffraction exoplanets which lie beyond reach for current state-of-the-art systems," said Deshler. "We are hopeful that this method might allow astronomers to push the boundaries of exoplanets accessible with direct imaging." The team says the technology needed to build and implement their quantum-optimized coronagraph already exists. They're now working to refine the device into a deployable system that meets performance targets. "The main limitation is the fidelity of the mode sorter," explained Ozer. "In the lab, we measure the 'purity' of the modes through a metric called the cross-talk matrix, which describes the undesired photon leakage that occurs between independent modes. Cross-talk is largely induced by manufacturing imperfections and small experimental misalignments. To successfully image Exo-Earths, […] the mode sorter must isolate each photon in the fundamental mode to better than one part in a billion if the exoplanet is to be resolved." Related Stories: — Doubts over signs of alien life on exoplanet K2-18b are rising: 'This is evidence of the scientific process at work' — James Webb Space Telescope finds water in the air of exotic 'sub-Neptune' exoplanet — Lightning on alien worlds may fail to spark life, simulations suggest The team says precision manufacturing is necessary to fabricate high-quality phase masks that can meet these "cross-talk" requirements. "We envision the use of advanced techniques, such as photolithography, additive manufacturing, or micromachining, to construct extremely precise diffractive surfaces," Deshler said. The duo hopes this technology will one day provide complementary data for future flagship telescope missions like the Habitable Worlds Observatory, a proposed successor to the Hubble Space Telescope, the JWST, and the Nancy Grace Roman Space Telescope. "Direct imaging is one of the few observation strategies that can measure the wavelength spectrum of an exoplanet," explained Ozer. "In turn this spectrum may contain clues about atmospheric composition of an exoplanet and reveal potential chemical biosignatures." "We imagine that mode-sorter driven coronagraphs could augment the astronomy toolkit and enable better characterization of sub-diffraction exoplanets," added Deshler. "However, the difficulty of exoplanet discovery warrants cross-validation with a multiplicity of observational techniques such as transits, velocimetry, and gravitational microlensing. Therefore, this technology is by no means a one-size-fits-all solution." The study was published on April 22 in the journal Optica.
Daily Mail
22-05-2025
- Science
- Daily Mail
Scientists discover an unknown bacteria that has never been seen on Earth inside China's space station
The search for life in space has led astronomers to look everywhere from the surface of Mars to the atmospheres of the most distant exoplanets. Now, scientists have discovered unknown bacteria that have never been seen on Earth - living inside a cabin on China 's Tiangong space station. The bacteria, named Niallia tiangongensis after the station, are a relative of a soil-dwelling bacterium from Earth. However, the researchers found that this unique bacteria has evolved special adaptations that help it survive in space. This includes specialized genes which help repair damage caused by the intense radiation found beyond Earth's atmosphere. Most surprisingly, the scientists found that the bacteria have evolved the ability to eat gelatin in order to create a tough protective 'biofilm'. While its closest relative on Earth is known to cause sepsis, it has not yet been determined whether Niallia tiangongensis poses a threat to humans. The researchers say that understanding the abilities of new space-faring bacteria is 'essential for safeguarding the health of astronauts'. The new species was found in samples taken from the station in 2023 by members of the Shenzhou-15 mission. The crew swabbed the walls of the station with sterile tissues, which were then frozen and sent back to Earth for analysis. When scientists analyzed these samples, they found a type of bacteria which was similar to the common soil-dwelling species Niallia circulans. Niallia circulans is a rod-shaped bacteria which spreads itself by dispersing spores and is commonly found in the ground, sewage, and in food. In immunocompromised patients, Niallia circulans can cause sepsis - a life-threatening condition caused by the body reacting improperly to a bacterial infection. Just like its earthly cousin, Niallia tiangongensis also propagates by spreading spores, which can survive extreme conditions. Niallia tiangongensis likely started as a small colony of Niallia circulans bacteria or spores, which slowly adapted to their new life in space after being taken onto the station. These adaptations help the bacteria survive in the nutrient-scarce space-station interior and resist the stresses of space. However, this is not the first time that humans have accidentally created new bacterial species by taking them into space. In April last year, NASA discovered 13 new strains of drug-resistant bacteria living on the International Space Station inside the air vents, exercise equipment, and toilets. Just like Niallia tiangongensis, the scientists believe these bacteria started out as species from Earth, which evolved over time after hitching a ride into space. Space agencies go to great lengths not to contaminate the controlled environments of space stations or other planets. But, as NASA is beginning to discover, it is almost impossible to prevent bacteria from getting a foothold in even the most sterile environment. NASA recently discovered that the 'clean rooms' used to prep the Phoenix Mars Lander were home to 53 strains of bacteria, including 26 previously unknown species. Bacteria are so ludicrously tough that the space agency has even launched a mission to swab the outside of the ISS to see if any germs might be surviving in the harsh vacuum of space. This is a pressing issue for the Chinese Space Agency and NASA since both organizations are currently attempting to establish permanent bases on the moon. Within the cramped confines of a remote space station, infections can spread rapidly between crew members. If novel, antibiotic-resistant bacteria develop inside the station, this could sweep through the crew and cause serious health risks. The overly sterile environment of a space station actually makes this risk worse by allowing a handful of hardy bacteria to thrive uninhibited. NASA recently found that an increase in rashes and cold sores experienced by astronauts on the ISS might actually be caused by the station being too clean. Without other bacteria competing for resources, germs from the astronauts' skin were thriving on the station walls and leading to more common infections. If nations are serious about keeping humans in space for good, they will need to find a way to manage and control the spread of these new bacterial species. Discovery of pulsars British astronomer Dame Jocelyn Bell Burnell was the first person to discover a pulsar in 1967 when she spotted a radio pulsar. Since then other types of pulsars that emit X-rays and gamma rays have also been spotted. Pulsars are essentially rotating, highly magnetised neutron stars but when they were first discovered it was believed they could have come from aliens. 'Wow!' radio signal In 1977, an astronomer looking for alien life in the night sky above Ohio spotted a radio signal so powerful that he excitedly wrote 'Wow!' next to his data. In 1977, an astronomer looking for alien life in the night sky above Ohio spotted a radio signal so powerful that he excitedly wrote 'Wow!' next to his data The 72-second blast, spotted by Dr Jerry Ehman through a radio telescope, came from Sagittarius but matched no known celestial object. Conspiracy theorists have since claimed that the 'Wow! signal', which was 30 times stronger than background radiation, was a message from intelligent extraterrestrials. Fossilised Martian microbes In 1996 Nasa and the White House made the explosive announcement that the rock contained traces of Martian bugs. The meteorite, catalogued as Allen Hills (ALH) 84001, crashed onto the frozen wastes of Antarctica 13,000 years ago and was recovered in 1984. Photographs were released showing elongated segmented objects that appeared strikingly lifelike. However, the excitement did not last long. Other scientists questioned whether the meteorite samples were contaminated. They also argued that heat generated when the rock was blasted into space may have created mineral structures that could be mistaken for microfossils. Behaviour of Tabby's Star in 2005 The star, otherwise known as KIC 8462852, is located 1,400 light years away and has baffled astronomers since being discovered in 2015. It dims at a much faster rate than other stars, which some experts have suggested is a sign of aliens harnessing the energy of a star. Recent studies have 'eliminated the possibility of an alien megastructure', and instead, suggests that a ring of dust could be causing the strange signals. Exoplanets in the Goldilocks zone in 2017 In February 2017 astronomers announced they had spotted a star system with planets that could support life just 39 light years away. Seven Earth-like planets were discovered orbiting nearby dwarf star 'Trappist-1', and all of them could have water at their surface, one of the key components of life. Three of the planets have such good conditions, that scientists say life may have already evolved on them. Researchers claim that they will know whether or not there is life on any of the planets within a decade, and said: 'This is just the beginning.'
