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Posts tagged "Exoplanets"

thenewenlightenmentage:

Should Humanity Try to Contact Intelligent Aliens?

Astronomers have detected nearly 2,000 alien planets to date. As that number continues to rise, so too does the prospect of finding intelligent extraterrestrial life.

In terms of the search for extraterrestrial intelligence (SETI), it may no longer be a matter of answering the “are we alone” question, some scientists say. Rather, just how crowded is the universe?

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thenewenlightenmentage:

Starshade Could Help Photograph Distant Planets

As a planet orbits near its sun, the bright stellar light interferes with observations made from Earth. To block the excess light, NASA scientists want to launch into space a large instrument called a starshade that will allow a space telescope to directly image an Earth-sized planet in an Earth-like orbit.

“A starshade removes most of the starlight by blocking it outside the telescope. It creates a shadow much like the Moon does during a solar eclipse,” said Jeremy Kasdin of Princeton University in an email.

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kenobi-wan-obi:

Length of Alien Planet’s ‘Day’ Clocked for 1st Time, an 8-Hour World

Astronomers have measured the rotation rate of an alien planet for the first time ever, finding that a huge Jupiter-like world called Beta Pictoris b has a day lasting just eight hours.

The equator of Beta Pictoris b, a gas giant about 10 times more massive than Jupiter, is moving at about 62,000 mph (100,000 km/h), researchers said — far faster than that of any planet in our solar system. In fact, Beta Pictoris b is the fastest-spinning planet yet seen.

In comparison, Jupiter’s equator is traveling at about 29,000 mph (47,000 km/h), while Earth’s is moving at just 1,060 mph (1,700 km/h). Days on these two familiar planets last about 10 hours and 24 hours, respectively.

kenobi-wan-obi:

Move Over Exoplanets, Exomoons May Harbour Life Too

In the Star Wars universe, everyone’s favourite furry aliens, the Ewoks, famously lived on the “forest moon of Endor”. In scientific terms, the Ewok’s home world would be referred to as an exomoon, which is simply a moon that orbits an exoplanet – any planet that orbits a star other than our sun.

Although more than 1,000 exoplanets have been discovered since the first one was found in 1995, only a handful of those are thought to be habitable, at least by life as we know it. New research shows that exomoons, too, could provide habitable environments. Although we are yet to find exomoons, we have good reasons to believe that there should be many, even more than exoplanets.

Goldilocks zone

Perhaps the most habitable planet found to date is the recently announced Kepler-186f. This is one of five exoplanets discovered by NASA’s Kepler satellite, all orbiting a small, faint, red dwarf star, 500 light years away in the constellation of Cygnus.

Kepler-186f is an Earth-sized planet that orbits its star in only 130 days and is about as distant from its star as Mercury is from the Sun. But, because the red dwarf is much dimmer than the Sun, Kepler-186f receives only about one-third of the energy that the Earth does. As a result, Kepler-186f lies at the outer edge of its star’s “habitable zone”. This is the hypothetical region of space surrounding a star in which liquid water may conceivably exist on the surface of any exoplanets.

In our own solar system, Venus lies too close to the Sun and is too hot. Mars lies too far from the Sun and is too cold. But Earth, of course, lies within the critical “Goldilocks zone”, where the temperature is just right.

Simply residing in the habitable zone, though, is no guarantee that an exoplanet has water oceans. The climate of a planet is much more complicated than we can capture with a simple calculation based on the distance of a planet from a star. We know that Mars probably had running water on its surface in the past, but now it is a frozen desert. Earth, meanwhile, was probably in a completely frozen “snowball” state about 650m years ago.

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kenobi-wan-obi:

First Earth-Size Planet That Could Support Life

For the first time, scientists have discovered an Earth-size alien planet in the habitable zone of its host star, an “Earth cousin” that just might have liquid water and the right conditions for life.

Image 1: This artist illustration shows what it might be like to stand on the surface of the planet Kepler-186f, the first-ever Earth-size planet to be found in the habitable zone of its star. Credit: Danielle Futselaa

Image 2: This artist illustration shows the planet Kepler-186f, the first Earth-size alien planet discovered in the habitable zone of its star. Credit: NASA Ames/SETI Institute/JPL-CalTech

The newfound planet, called Kepler-186f, was first spotted by NASA’s Kepler space telescope and circles a dim red dwarf star about 490 light-years from Earth. While the host star is dimmer than Earth’s sun and the planet is slightly bigger than Earth, the positioning of the alien world coupled with its size suggests that Kepler-186f could have water on its surface, scientists say. You can learn more about the amazing alien planet find in a video produced by Space.com.

"One of the things we’ve been looking for is maybe an Earth twin, which is an Earth-size planet in the habitable zone of a sunlike star," Tom Barclay, Kepler scientist and co-author of the new exoplanet research, told Space.com. "This [Kepler-186f] is an Earth-size planet in the habitable zone of a cooler star. So, while it’s not an Earth twin, it is perhaps an Earth cousin. It has similar characteristics, but a different parent."

Scientists think that Kepler-186f — the outermost of five planets found to be orbiting the star Kepler-186 — orbits at a distance of 32.5 million miles (52.4 million kilometers), theoretically within the habitable zone for a red dwarf.

Earth orbits the sun from an average distance of about 93 million miles (150 million km), but the sun is larger and brighter than the Kepler-186 star, meaning that the sun’s habitable zone begins farther out from the star by comparison to Kepler-186.

"This is the first definitive Earth-sized planet found in the habitable zone around another star," Elisa Quintana, of the SETI Institute and NASA’s Ames Research Center and the lead author of a new study detailing the findings, said in a statement.

Other planets of various sizes have been found in the habitable zones of their stars. However, Kepler-186f is the first alien planet this close to Earth in size found orbiting in that potentially life-supporting area of an extrasolar system, according to exoplanet scientists.

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pennyfornasa:

Astronomers Find First Earth-Sized Planet That Could Support Life!

NASA’s Kepler Space Telescope has discovered the first Earth-sized planet in the habitable zone of another star. The habitable zone is the region around a star in which planets are capable of supporting liquid water at their surface. This region is sometimes referred to as the Goldilocks zone because it defines the area where the conditions are not too hot or too cold, but “just right” for planets to support water on the surface. The discovery Kepler-186f confirms that planets of Earth’s size exist in the habitable zone of stars other than our Sun. It also marks a significant step forward in finding other planets similar to our own.

Read more about the exciting discovery of Kepler-186f here: http://www.nasa.gov/ames/kepler/nasas-kepler-discovers-first-earth-size-planet-in-the-habitable-zone-of-another-star/index.html#.U1BDx6ZLtFt

kenobi-wan-obi:

First ‘Exomoon’ Around Alien Planet Possibly Found

For the first time ever, astronomers may have spotted a moon circling an alien planet — though they’ll probably never know for sure exactly what they’ve found.

A team of scientists detected a pair of faraway objects that could be a giant Jupiter-like alien planet and a rocky exomoon flying freely through space, or a small dim star hosting a planet about 18 times more massive than Earth.

The astronomers used a technique called gravitational microlensing, watching what happens a big foreground object passes in front of a star from our perspective on Earth. The nearby body’s gravitational field bends and magnifies the light from the distant star, acting like a lens.

Analyzing lensing events can reveal a great deal about the foreground object — for example, in the case of a star, whether it hosts a planet and, if so, how massive that world is compared to the star.

In the new study, the team observed one intriguing lensing event using telescopes in New Zealand and the Australian state of Tasmania. They determined that the foreground object has an orbiting companion about 0.05 percent as massive as itself.

"One possibility is for the lensing system to be a planet and its moon, which if true, would be a spectacular discovery of a totally new type of system," Wes Traub, chief scientist for NASA’s Exoplanet Exploration Program office at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., said in a statement.

"The researchers’ models point to the moon solution, but if you simply look at what scenario is more likely in nature, the star solution wins," added Traub, who was not involved in the study.

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kenobi-wan-obi:

New Dwarf Planet Found at Solar System’s Edge, Hints at Possible Faraway ‘Planet X’

Astronomers have found a new dwarf planet far beyond Pluto’s orbit, suggesting that this distant realm contains millions of undiscovered objects — including, perhaps, a world larger than Earth.

Image 1: Orbit diagram for the outer solar system. The sun and terrestrial planets are at the center. The orbits of the four giant planet Jupiter, Saturn, Uranus and Neptune are shown by purple solid circles. The Kuiper Belt (including Pluto) is shown by the dotted light blue region just beyond the giant planets. Sedna’s orbit is shown in orange while 2012 VP113’s orbit is shown in red. Both objects are currently near their closest approach to the sun. They would be too faint to detect when in the outer parts of their orbits. Credit: Scott S. Sheppard: Carnegie Institution for Science

Image 2: The discovery images of 2012 VP113, which has the most distant orbit known in our Solar System. Three images of the night sky, each taken about 2 hours apart, were combined into one. The first image was artificially colored red, second green and third blue. 2012 VP113 moved between each image as seen by the red, green and blue dots. The background stars and galaxies did not move and thus their red, green and blue images combine to show up as white sources. Credit: Scott S. Sheppard: Carnegie Institution for Science

Image 3: These images show the discovery of the new inner Oort cloud object 2012 VP113 taken about 2 hours apart on UT November 5, 2012. The motion of 2012 VP113 clearly stands out compared to the steady state background stars and galaxies. Credit: Scott S. Sheppard: Carnegie Institution for Science

The newfound celestial body, called 2012 VP113, joins the dwarf planet Sedna as a confirmed resident of a far-flung and largely unexplored region scientists call the “inner Oort Cloud.” Further, 2012 VP113 and Sedna may have been pulled into their long, looping orbits by a big planet lurking unseen in these frigid depths.

"These two objects are just the tip of the iceberg," study co-author Chadwick Trujillo, of the Gemini Observatory in Hawaii, told Space.com. "They exist in a part of the solar system that we used to think was pretty devoid of matter. It just goes to show how little we actually know about the solar system."

Probing the depths

For several decades, astronomers have divided our solar system into three main parts: an inner zone containing the rocky planets, such as Earth and Mars; a middle realm housing the gas giants Saturn, Jupiter, Uranus and Neptune; and an outer region called the Kuiper Belt, populated by distant and icy worlds like Pluto.

The discovery of Sedna in 2003 hinted that this map is incomplete. Sedna, which is about 620 miles (1,000 kilometers) wide, has an incredibly elliptical orbit, coming no closer to the sun than 76 astronomical units (AU) and going all the way out to 940 AU or so at its most distant point. (One AU, the distance from Earth to the sun, is about 93 million miles, or 150 million km.)

That puts Sedna in the far outer reaches of the solar system. For comparison, Pluto’s orbit takes it between 29 and 49 AU from the sun.

And now astronomers know Sedna is not alone out there. Trujillo and Scott Sheppard, of the Carnegie Institution for Science in Washington, D.C., discovered 2012 VP113 using the Dark Energy Camera, which is installed on a 4-meter telescope at the Cerro Tololo Inter-American Observatory in Chile.

Follow-up observations by the 6.5-meter Magellan Telescopes at Las Campanas Observatory, also in Chile, helped Trujillo and Sheppard determine details of 2012 VP113’s orbit and learn a bit more about the object.

The body comes no closer to the sun than 80 AU, and it gets as far away as 452 AU. About 280 miles (450 km) wide, 2012 VP113 is large enough to qualify as a dwarf planet if it’s composed primarily of ice, researchers said. (By definition, dwarf planets must be big enough for their gravity to mold them into spheres; the mass required for this to happen depends upon the objects’ composition.)

The inner Oort Cloud

Objects as distant as Sedna and 2012 VP113 are incredibly difficult to detect; astronomers really only get a chance when the bodies near their closest approach to the sun.

Based on the amount of sky the scientists searched, Trujillo and Sheppard estimate that about 900 bodies larger than Sedna may exist in this faraway realm, which the astronomers dub the inner Oort Cloud. (The true Oort Cloud is an icy shell around the solar system that begins perhaps 5,000 AU from the sun and contains trillions of comets.)

The total population of objects in the inner Oort Cloud, in fact, may exceed that of the Kuiper Belt and the main asteroid belt between Mars and Jupiter, researchers said.

Planet X?

Astronomers don’t know much about the origin or evolutionary history of Sedna and 2012 VP113 at this point. The objects may have formed closer to the sun, for example, before getting pushed out by gravitational interactions with other stars — perhaps “sister stars” from the sun’s birth cluster, researchers said. Or inner Oort Cloud objects may be alien bodies that the sun plucked from another solar system during a stellar close encounter.

It’s also possible that 2012 VP113 and its neighbors were knocked from the Kuiper Belt to the inner Oort Cloud when a big planet was booted outward long ago. This planet may have been ejected from the solar system entirely, or it may still be there in the extreme outer reaches, waiting to be discovered.

Indeed, certain characteristics of the orbits of Sedna, 2012 VP113 and several of the most distant Kuiper Belt objects are consistent with the continued presence of a big and extremely faraway “perturber,” researchers said. It’s possible that a planet roughly 10 times more massive than Earth located hundreds of AU from the sun is shepherding these bodies into their current orbits.

Such supposition is far from proof that an undiscovered “Planet X” actually exists, Trujillo stressed. But he did say that the door is open, noting that an Earth-mass body at 250 AU from the sun would likely be undetectable at present.

"It raises the possibility that there could be stuff out there of significant mass, Earth-mass or larger, that we don’t know about," he said.

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kenobi-wan-obi:

Where’s Planet X? NASA Space Telescope Discovers Thousands of New Stars, But No ‘Nemesis’

A NASA spacecraft has pounded another nail into the coffin of the hypothetical solar system body known as “Planet X” or “Nemesis.”

After scanning the entire sky, the space agency’s Wide-Field Infrared Survey Explorer (WISE) found no signs of an undiscovered planet or other large body in the outer reaches of the solar system. The probe did, however, find several thousand new objects much farther out.

"The outer solar system probably does not contain a large gas planet, or a small, companion star," Kevin Luhman of Penn State University said in a statement. Luhman is the author of one of two new papers appearing in the Astrophysical Journal that describe the results of WISE’s search.

'Hiding in plain sight'

WISE scanned the sky throughout 2010 and in early 2011, with a six-month gap between the two observations. By comparing the two sets of infrared images, astronomers could identify objects that had moved slightly across the sky. WISE imaged nearly 750 million stars, asteroids, and galaxies, some of which had never been spotted before.

Luhman’s study found 762 new objects among the data, but no signs of a Saturn-sized object out to 10,000 times the Earth-sun distance (an astronomical unit, or AU; 1 AU is about 93 million miles, or 150 million kilometers). Nor did Luhman spot any Jupiter-size or larger objects out to 26,000 AUs.

A second study, led by Davy Kirkpatrick of NASA’s Infrared and Processing Analysis Center at the California Institute of Technology, discovered 3,525 new stars and brown dwarfs, some of which overlapped Luhman’s finds. Brown dwarfs are objects that are larger than planets but too small to sustain fusion in their core as true stars do. As a result, they are far dimmer and more challenging to observe.

"We’re finding objects that were totally overlooked before," Kirkpatrick said in a statement.

Some of these include extremely close stars, such as one located only 20 light-years away in the constellation Norma. A study that looked at WISE data last year found a pair of brown dwarfs just 6.5 light-years from Earth, making it the closest star system discovered in almost 100 years.

"Neighboring star systems that have been hiding in plain sight just jump out in the WISE data," mission principal investigator Ned Wright of UCLA said in a statement.

kenobi-wan-obi:

Nearly Every Star Hosts at Least One Alien Planet

The vast majority of stars in our Milky Way galaxy host planets, many of which may be capable of supporting life as we know it, a new study suggests.

Astronomers have detected eight new exoplanet candidates circling nearby red dwarf stars, which make up at least 75 percent of the galaxy’s 100 billion or so stars. Three of these worlds are just slightly bigger than Earth and orbit in the “habitable zone,” the range of distances from a parent star where liquid water could exist on a planet’s surface.

The new finds imply that virtually all red dwarfs throughout the Milky Way have planets, and at least 25 percent of these stars in the sun’s own neighborhood host habitable-zone “super-Earths,” researchers said.

kenobi-wan-obi:

Population of Known Alien Planets Nearly Doubles as NASA Discovers 715 New Worlds

NASA’s Kepler space telescope has discovered more than 700 new exoplanets, nearly doubling the current number of confirmed alien worlds.

The 715 newfound planets, which scientists announced today (Feb. 26), boost the total alien-world tally to between 1,500 and 1,800, depending on which of the five main extrasolar planet discovery catalogs is used. The Kepler mission is responsible for more than half of these finds, hauling in 961 exoplanets to date, with thousands more candidates awaiting confirmation by follow-up investigations.

"This is the largest windfall of planets — not exoplanet candidates, mind you, but actually validated exoplanets — that’s ever been announced at one time," Douglas Hudgins, exoplanet exploration program scientist at NASA’s Astrophysics Division in Washington, told reporters today.

About 94 percent of the new alien worlds are smaller than Neptune, researchers said, further bolstering earlier Kepler observations that suggested the Milky Way galaxy abounds with rocky planets like Earth.

Most of the 715 exoplanets orbit closely to their parent stars, making them too hot to support life as we know it. But four of the worlds are less than 2.5 times the size of Earth and reside in the “habitable zone,” that just-right range of distances that could allow liquid water to exist on their surfaces.

NASA’s Kepler mission announced Wednesday the discovery of 715 new planets. These newly-verified worlds orbit 305 stars, revealing multiple-planet systems much like our own solar system.

Nearly 95 percent of these planets are smaller than Neptune, which is almost four times the size of Earth. This discovery marks a significant increase in the number of known small-sized planets more akin to Earth than previously identified exoplanets, which are planets outside our solar system.

“The Kepler team continues to amaze and excite us with their planet hunting results,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “That these new planets and solar systems look somewhat like our own, portends a great future when we have the James Webb Space Telescope in space to characterize the new worlds.”

Since the discovery of the first planets outside our solar system roughly two decades ago, verification has been a laborious planet-by-planet process. Now, scientists have a statistical technique that can be applied to many planets at once when they are found in systems that harbor more than one planet around the same star.

To verify this bounty of planets, a research team co-led by Jack Lissauer, planetary scientist at NASA’s Ames Research Center in Moffett Field, Calif., analyzed stars with more than one potential planet, all of which were detected in the first two years of Kepler’s observations — May 2009 to March 2011.

The research team used a technique called verification by multiplicity, which relies in part on the logic of probability. Kepler observes 150,000 stars, and has found a few thousand of those to have planet candidates. If the candidates were randomly distributed among Kepler’s stars, only a handful would have more than one planet candidate. However, Kepler observed hundreds of stars that have multiple planet candidates. Through a careful study of this sample, these 715 new planets were verified.

This method can be likened to the behavior we know of lions and lionesses. In our imaginary savannah, the lions are the Kepler stars and the lionesses are the planet candidates. The lionesses would sometimes be observed grouped together whereas lions tend to roam on their own. If you see two lions it could be a lion and a lioness or it could be two lions. But if more than two large felines are gathered, then it is very likely to be a lion and his pride. Thus, through multiplicity the lioness can be reliably identified in much the same way multiple planet candidates can be found around the same star.

"Four years ago, Kepler began a string of announcements of first hundreds, then thousands, of planet candidates —but they were only candidate worlds," said Lissauer. "We’ve now developed a process to verify multiple planet candidates in bulk to deliver planets wholesale, and have used it to unveil a veritable bonanza of new worlds."

These multiple-planet systems are fertile grounds for studying individual planets and the configuration of planetary neighborhoods. This provides clues to planet formation.

Four of these new planets are less than 2.5 times the size of Earth and orbit in their sun’s habitable zone, defined as the range of distance from a star where the surface temperature of an orbiting planet may be suitable for life-giving liquid water.

One of these new habitable zone planets, called Kepler-296f, orbits a star half the size and 5 percent as bright as our sun. Kepler-296f is twice the size of Earth, but scientists do not know whether the planet is a gaseous world, with a thick hydrogen-helium envelope, or it is a water world surrounded by a deep ocean.

"From this study we learn planets in these multi-systems are small and their orbits are flat and circular — resembling pancakes — not your classical view of an atom," said Jason Rowe, research scientist at the SETI Institute in Mountain View, Calif., and co-leader of the research. "The more we explore the more we find familiar traces of ourselves amongst the stars that remind us of home."

This latest discovery brings the confirmed count of planets outside our solar system to nearly 1,700. As we continue to reach toward the stars, each discovery brings us one step closer to a more accurate understanding of our place in the galaxy.

Launched in March 2009, Kepler is the first NASA mission to find potentially habitable Earth-size planets. Discoveries include more than 3,600 planet candidates, of which 961 have been verified as bona-fide worlds.

The findings papers will be published March 10 in The Astrophysical Journal and are available for download at:
http://www.nasa.gov/ames/kepler/digital-press-kit-kepler-planet-bonanza

Ames is responsible for the Kepler mission concept, ground system development, mission operations and science data analysis. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA’s 10th Discovery Mission and was funded by the agency’s Science Mission Directorate.

kenobi-wan-obi:

Incredible Technology: How to Search for Advanced Alien Civilizations

Look at a picture of the Earth at night, and the world appears to be, quite literally, glowing. Now, scientists are starting to look for signs of advanced alien civilizations by the glow given off by technology used to harvest the energy from a star or even an entire galaxy.

Theoretical physicist and mathematician Freeman Dyson first proposed the idea that advanced alien civilizations might develop technology to encircle a star and harvest most of its power, a structure now known as a Dyson sphere. If these objects do exist, astronomers might be able to detect the waste heat they produce using telescopes that peer into space using infrared light.

"The main point," Dyson told LiveScience, "is looking for aliens who don’t want to communicate. My question was, ‘How do you look for silent aliens?’ They have to radiate away their waste heat. The only way to do that is to radiate lots of infrared radiation."

Now, astronomers at Pennsylvania State University are starting to narrow the search for Dyson spheres. But the search has only just begun, and may take hundreds of years, Dyson said. Finding Dyson spheres isn’t inevitable, but “it’s certainly possible,” he said.

(via afro-dominicano)

kenobi-wan-obi:

Hubble Traces Subtle Signals of Water on Hazy Worlds

Using the powerful eye of NASA’s Hubble Space Telescope, two teams of scientists have found faint signatures of water in the atmospheres of five distant planets.

The presence of atmospheric water was reported previously on a few exoplanets orbiting stars beyond our solar system, but this is the first study to conclusively measure and compare the profiles and intensities of these signatures on multiple worlds.

The five planets — WASP-17b, HD209458b, WASP-12b, WASP-19b and XO-1b — orbit nearby stars. The strengths of their water signatures varied. WASP-17b, a planet with an especially puffed-up atmosphere, and HD209458b had the strongest signals. The signatures for the other three planets, WASP-12b, WASP-19b and XO-1b, also are consistent with water.

"We’re very confident that we see a water signature for multiple planets," said Avi Mandell, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and lead author of an Astrophysical Journal paper, published today, describing the findings for WASP-12b, WASP-17b and WASP-19b. "This work really opens the door for comparing how much water is present in atmospheres on different kinds of exoplanets, for example hotter versus cooler ones."

The studies were part of a census of exoplanet atmospheres led by L. Drake Deming of the University of Maryland in College Park. Both teams used Hubble’s Wide Field Camera 3 to explore the details of absorption of light through the planets’ atmospheres. The observations were made in a range of infrared wavelengths where the water signature, if present, would appear. The teams compared the shapes and intensities of the absorption profiles, and the consistency of the signatures gave them confidence they saw water. The observations demonstrate Hubble’s continuing exemplary performance in exoplanet research.

"To actually detect the atmosphere of an exoplanet is extraordinarily difficult. But we were able to pull out a very clear signal, and it is water," said Deming, whose team reported results for HD209458b and XO-1b in a Sept. 10 paper in the same journal. Deming’s team employed a new technique with longer exposure times, which increased the sensitivity of their measurements.

Continue to Full News Release

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kenobi-wan-obi:

How to Find Alien Life on Dying Planets

If life does exist anywhere else in the universe, it may only be fleeting. Now scientists are researching how signs of life might look on dying planets.

Astronomers have discovered hundreds of distant alien planets in the past two decades. Future missions could detect potential signs of life called biosignatures on those worlds, such as oxygen or methane in their atmospheres.

Astrobiologist Jack O’Malley-James at the University of St. Andrews in Fife, Scotland and his colleagues noted that biosignatures of life on Earth have not remained the same over time, but have altered considerably over its history. This led the researchers to speculate about how Earth and other planets might look in the future.

"Astrobiology as a field seems to put a lot more focus on the origins of life and how to find life beyond Earth, but less emphasis is put on the end of life, which is what got me interested in finding out more about how biospheres on other planets might meet their ends, and by extension, how long we could expect to detect life on a habitable planet over the course of its habitable lifetime," said O’Malley-James, the lead author of the study.