Latest news with #ProximaCentauri
Forbes
4 days 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.
Yahoo
21-05-2025
- Science
- Yahoo
Lightning on alien worlds may fail to spark life, simulations suggest
When you buy through links on our articles, Future and its syndication partners may earn a commission. Life as we know it may require lightning, as it's one of the few energy sources a planet has available to create complex chemical compounds. Now, new research has found that lightning, while not very common, can occur on tidally locked exoplanets like our nearest neighbor, Proxima b. But the peculiar nature of lightning on tidally locked planets poses some challenges for their ability to host life. A typical lightning bolt can reach temperatures of up to 30,000 kelvins (over 50,000 degrees Fahrenheit). That's more than powerful enough to destroy common atmospheric gases and reassemble them into new compounds. On modern-day Earth, lightning breaks down molecular nitrogen and oxygen and creates nitrogen oxides. On the early Earth, however — before the rise in atmospheric oxygen due to photosynthesis — lightning may have played a crucial role in creating many prebiotic compounds, which are molecules that form the building blocks of proteins. We don't know if any exoplanets host life. We have yet to find an Earth twin with the right orbit around a sun-like star, but we have come close. Take Proxima b, an exoplanet that orbits the nearest star to the solar system. Proxima b is roughly the size of Earth and orbits its star, Proxima Centauri, at just the right distance to potentially support liquid water. But Proxima Centauri is a red dwarf star, with just a fraction of the sun's brightness and size. Proxima b has an incredibly tight orbit, with an entire year lasting just 11 days. Because of its proximity to its parent star, Proxima b is almost certainly tidally locked, meaning it always shows one face toward the star, just like the moon always shows only one face toward Earth. Because of its rotation, our planet hosts a rich weather system. This weather system makes lightning storms very common, with roughly 100 lightning strikes happening somewhere on the globe every second. But can a tidally locked planet create lightning storms? To answer this question, a team of researchers led by Denis Sergeev at the University of Bristol in the U.K. created atmospheric simulations of a mock tidally locked planet, using the same kinds of simulations that climatologists use to study Earth's weather. In April, they submitted their paper for publication in the journal Monthly Notices of the Royal Astronomical Society. The researchers found that the tidally locked planet could produce significant lightning storms, but that these storms were far different from those on Earth. These planets around small stars hosted significantly fewer lightning strikes — only a handful of strikes per second, the simulations showed. And that was for planets with much thinner atmospheres than Earth's atmosphere — roughly a quarter of our planet's atmospheric pressure. Higher-pressure atmospheres suppressed the formation of convection cells that could drive cloud formation and generate the necessary friction to produce lightning. Atmospheres with pressures 10 times greater than Earth's could produce only a single lightning strike every few minutes. Unlike on Earth, all the heat from the star pours onto one side on a tidally locked planet. That heat then flows through powerful jet streams that race from the permanent dayside to the nightside. This powered strong weather mostly on the dayside, with lightning strikes clustered in a circular area, the researchers found. However, in some cases, lightning strikes happened mostly on the nightside, just past the day-night terminator line. It was only there that there was enough atmospheric activity to generate the conditions needed for lightning. Related stories: —How could life survive on tidally locked planets? —Was life on Earth sparked by cloud-to-ground lightning strikes? —The 10 most Earth-like exoplanets But that doesn't mean that this lightning could necessarily be guaranteed to help produce life. For one, lightning strikes are far less common there than on Earth and thus may not be enough to generate sufficient prebiotic compounds. Another challenge is that the strikes are not distributed evenly around the globe. They tend to be concentrated on the dayside, which may be too hot to support life. Still, the story of life on exoplanets, even tidally locked ones, is not over. And nature has shown time and time again that life … finds a way.
Yahoo
19-05-2025
- Science
- Yahoo
TRAPPIST-1 Planets Could Be Swimming in Water, Study Shows
A seven-planet system some 40 light-years from Earth could be swimming in water, new research shows. In February 2017 scientists announced the discovery of several exoplanets orbiting the red dwarf star TRAPPIST-1, and ever since astronomers have keenly monitored the system for potential signs of life (aka biosignatures). According to recent findings, these planets may have an abundance of one of the most crucial elements for life: water. Since the discovery, scientists have gone back and forth on whether any planets in the TRAPPIST-1 system could be habitable. Much like the Proxima Centauri system and its Earth-like planet (Proxima b), the debate has centered on their parent stars: M-type (red dwarf) stars. These stars are smaller and cooler than our Sun and are noted for the way they are prone to flare activity. Another major question is the availability of water in this system. Previous findings have indicated that planets orbiting red dwarfs may have an overabundance of water, but they may not hold onto it for long. These findings are supported by other research that has revealed that these planets experience high rates of water lost to space, caused by the intense ultraviolet (UV) radiation from their host star. In a new study, a team of researchers led by astrobiologist Trent Thomas from the University of Washington addressed recent findings by the JWST. Recent observations by JWST of TRAPPIST-1 c ruled out a thick carbon dioxide atmosphere, indicating that the planet is not as "Venus-like" as previously thought. However, these observations did not rule out the presence of water vapor or oxygen produced by its chemical dissociation. As the team explained in their paper, "the maintenance of atmospheric water vapor would require a present-day water source, such as volcanic outgassing." To investigate this possibility and estimate plausible outgassing rates on the TRAPPIST-1 planets, the team developed a theoretical outgassing model based on the rocky planets of the Solar System ( Mercury, Venus, Earth, and Mars). They then applied filters based on observations of the system and what is known about its geochemistry to constrain plausible scenarios. Their findings indicated that the outgassing rates of all seven planets would be between 0.03 and eight times that of Earth. However, they also found that magma emplacement rates (the speed at which magma moves through a planet) were similar to those of Mars. While there are indications that Mars still has magma beneath its surface, it is considered 'volcanically dead'. The same may be true of the TRAPPIST-1 planets. "Our model results for magma emplacement rates also indicate that the TRAPPIST-1 planets are currently more likely to have low-to-no volcanic activity," the researchers write in their paper. "Our results indicate that the water outgassing rates on the TRAPPIST-1 planets are more likely to be lower than Earth's, but the plausible range also includes outgassing rates that are an order of magnitude higher than Earth's." Their results further indicated that the TRAPPIST-1 planets may have relatively dry Earth-like mantles. But as they emphasized, it is possible that water could make up to 1 percent of their mass fractions. "Our results indicate that drier mantles are preferred within the broader explored range of mantle water content," the team explains. "This arises due to our assumption that the TRAPPIST-1 planets have terrestrial interiors with mantle water contents that remain below 1 percent by weight upper limit throughout the 5.4 billion-year age of the TRAPPIST-1 system. The preference for lower mantle H2O values is more consistent with Earth's mantle water content." This is especially interesting considering that while water covers about 71 percent of Earth's surface, it constitutes only about 0.02 percent of its total mass. This could mean that planets orbiting within TRAPPIST-1's habitable zone are volcanically inactive and have varying degrees of water, ranging from potential 'water worlds' and barren rocky worlds to Earth-like planets covered in oceans. These results reinforce the idea that the TRAPPIST-1 system has no shortage of water. Unfortunately, many questions remain about its habitability. Fortunately, Webb's observations of TRAPPIST-1 (and other red dwarf systems) are still in their infancy. Additional observations will allow astronomers to constrain the potential habitability of this system. Their findings were reported in a preprint available on arXiv. Unknown Species of Bacteria Discovered in China's Space Station NASA Mission Captures Eerie New View of The Moon And Sun Mysteriously Perfect Sphere Spotted in Space by Astronomers
The Guardian
03-05-2025
- The Guardian
What links Esperanza Spalding and Kim Deal? The Saturday quiz
1 The longest direct flight from London goes to which city?2 Until 1752, when did the new year officially begin in England?3 Which action film hero suffers from ophidiophobia?4 AE Stallings succeeded Alice Oswald in what role?5 Which country's president was shot by his intelligence chief in 1979?6 Which marsupial is native to North America?7 Vanwall, in 1958, was the first winner of what title?8 Who wrote Natural History, the longest surviving single Roman text?What links: 9 Lumbini; Bodh Gaya; Sarnath; Kushinagar?10 51 Pegasi b; Kepler-22b; Proxima Centauri b; Trappist-1 system?11 Miller; Marshall; O'Hanlon; Little; Gilet?12 Gun; orlop; poop; quarter; upper; well?13 Chateau de Châlus-Chabrol; Pontefract Castle; Bosworth Field?14 Birmingham (1); Liverpool (6); London (2); Manchester (4); Nottingham (2)?15 Kim Deal; Kim Gordon; Carol Kaye; Esperanza Spalding; Tina Weymouth? 1 Perth.2 25 March (Lady Day).3 Indiana Jones (fear of snakes).4 Oxford professor of poetry.5 South Korea.6 Virginia opossum (possum).7 Formula One Constructors' Championship.8 Pliny the Elder.9 Pilgrimage sites from the life of Buddha: birthplace; achieved enlightenment; first teaching; died.10 Exoplanets.11 Successive lead actors in Death in Paradise.12 Types of ships' deck.13 Death locations of Richard I, II and III.14 European Cup/UEFA Champions League (men's) wins by city: Aston Villa; Liverpool; Chelsea; United and City; Forest.15 Female bass players.
Yahoo
16-02-2025
- Science
- Yahoo
Alpha Centauri Sending Stream of Objects Into Our Solar System, Scientists Propose
The detection of a large interstellar object in 2017 named 'Oumuamua was a landmark discovery. Figuring out where the wayward traveler came from, though, is another challenge entirely, especially since it subsequently cruised back out of our star system. Nevertheless, that hasn't stopped intrepid astronomers from trying. In a case study published in the Planetary Science Journal and spotlighted by Universe Today, the researchers from The University of Western Ontario hypothesize a scenario in which our nearest stellar neighbor, Alpha Centauri, may be sending a steady stream of "interstellar material" our way. And tantalizingly, what they found suggests that our solar system may already be flooded with visitors from the star system, which is about 4.25 light years away. These objects range from microscopic in size to well over 100 yards in diameter — a far more significant presence than the background level of gas and dust diffused throughout the cosmos. However, the odds of encountering one of these objects within the heart our solar system remain exceedingly low, with only a one-in-a-million chance that an interstellar visitor is located within ten astronomical units, or just short of one billion miles, of the Sun, according to the scientists. Though it appears as a single bright speck in the sky, Alpha Centauri is actually a triple star system, with several suspected exoplanets, including a super-Earth called Proxima Centauri b, with more thought to be lurking in the shadows. Two of the stars are Sun-like ones locked in a binary dance, while another star, a dim red dwarf, acts as the proverbial third wheel. And with all those big personalities involved and clashing gravitational egos, it's likely that Alpha Centauri boots out a significant amount of material, some of which may have reached the Oort Cloud, a shell of icy objects that surrounds the solar system, the researchers said. Alpha Centauri is also moving towards us, and in some 28,000 years from now, it'll reach its closest point at a distance of a little over three light years away, raising the odds of an interstellar influx in the future, too. "Though mature star systems likely eject less material than those in their planet-forming years, the presence of multiple stars and planets increases the likelihood of gravitational scattering of members from any remnant planetesimal reservoirs, much as asteroids or comets are currently being ejected from our solar system," the researchers wrote in the study. In fact, the astronomers estimated there could be over 1,000,000 objects larger than 328 feet in diameter from the nearby system lurking in the Oort Cloud. For reference, 'Oumuamua is believed to be anywhere between 328 to 3,280 feet long. That's a lot of refugees. It's unlikely we'll ever detect the vast majority of them, though. And when you consider the astronomers determined that particles as small as just ten microns, or about the size of a human blood cell, could survive the ten million-year journey over, it sounds like our corner of the universe may be awash with interstellar particles that even our most advanced instruments will have no chance of picking up on. A silver lining: the authors predict that around ten Alpha Centauri rejects could enter the Earth's atmosphere, where they'd be detectable as meteorites. With any luck, some of them could originate from one of the star system's exoplanets, providing a potential glimpse of worlds light years away. "A thorough understanding of the mechanisms by which material could be transferred from Alpha Centauri to the solar system not only deepens our knowledge of interstellar transport but also opens new pathways for exploring the interconnectedness of stellar systems and the potential for material exchange across the Galaxy," the paper reads. More on space: Don't Panic, But the Chances of That City Killer Asteroid Hitting Earth Just Almost Doubled
