NASA scientists found faint signatures of water in the atmospheres of five distant planets orbiting three different stars. All five planets appear to be hazy. Credit: NASA, ESA, A. Mandell (Goddard Space Flight Center), and D. Deming (University of Maryland, College Park)
The Hubble Space Telescope has spied five alien worlds around distant stars that show clear signs of water vapor filling their atmospheres, according to a new study. The find represents the first conclusive detection and comparison of water vapor in the atmosphere of planets orbiting nearby stars.
While they all have unromantic names like WASP-17b, HD209458b, WASP-12b, WASP-19b, and XO-1b, they also all orbit nearby stars and show signs of water vapor in their atmospheres.
These “exoplanets” are no place for life, since each is classified as a hot Jupiter—gas giants that circle very closely to their parent suns. However, clear chemical fingerprints of water vapor were detected in light reflected off their uppermost cloud decks and seen by the storied space telescope.
“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,” co-author Drake Deming, an astronomer at the University of Maryland, said in a statement.
The orbiting observatory was able to tease out the faint telltale signals of water by examining the amount of starlight that is absorbed in infrared wavelengths as it passes through the planetary atmospheres while it transits in front of their host star.
To determine what’s in the atmosphere of an exoplanet, astronomers watch the planet pass in front of its host star and look at which wavelengths of light are transmitted and which are partially absorbed.
Credit: NASA’s Goddard Space Flight Center
“We’re very confident that we see a water signature for multiple planets,” said lead author Avi Mandell, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
What tricked astronomers into initially missing out on the fainter-than-expected water signatures was that a blanket of haze surrounds the planets, blocking the absorption lines of water from coming through. These findings now suggest to exoplanet researchers that hazy clouds may be common on worlds with water-filled atmospheres that orbit their parent stars tightly.
“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,” added Mandell.
The exoplanet watery atmosphere study was published this week in the Astrophysical Journal.
Re: At Least 8.8 Billion Earth-Size, Just-Right Planets Found, Study Says
Wow.
Powerful Planet Finder Turns Its Eye to the Sky
This image taken by the Gemini Planet Imager (GPI) shows a planet orbiting the star Beta Pictoris. In addition to the image, the GPI obtains spectral information from every pixel element in the field of view, allowing scientists to study the planet in great detail. Image credit: Gemini/Christian Marois, NRC Canada. January 07, 2014
After nearly a decade of development, construction and testing, the world's most advanced instrument for directly imaging and analyzing planets around other stars is pointing skyward and collecting light from distant worlds.
The instrument, called the Gemini Planet Imager (GPI), was designed, built, and optimized for imaging giant planets next to bright stars, in addition to studying dusty disks around young stars. It is the most advanced instrument of its kind to be deployed on one of the world's biggest telescopes - the 26-foot (8-meter) Gemini South telescope in Chile.
Imaging a planet next to a star is a tricky task. The planet is much fainter than its star, and also appears very close. These challenges make the act of separating the planet's light from the glare of the star difficult. NASA's Jet Propulsion Laboratory in Pasadena, Calif., contributed to the project by designing and building an ultra-precise infrared sensor to measure small distortions in starlight that might mask a planet.
"Our tasks were two-fold," said Kent Wallace, JPL's subsystem technical lead for the project. "First, keep the star centered on the instrument so that its glare is blocked as much as possible. Second, ensure the instrument itself is stable during the very long exposures required to image faint companions."
GPI detects infrared, or heat, radiation from young Jupiter-like planets in wide orbits around other stars. Those are equivalent to the giant planets in our own solar system not long after their formation. Every planet GPI sees can be studied in detail, revealing components of their atmospheres.
Although GPI was designed to look at distant planets, it can also observe objects in our solar system. Test images of Jupiter's moon Europa, for example, can allow scientists to map changes in the satellite's surface composition. The images were released today at the 223rd meeting of the American Astronomical Society in Washington.
Re: At Least 8.8 Billion Earth-Size, Just-Right Planets Found, Study Says
Stunning first light images emerge from Gemini Planet Imager
Probing the environments of distant stars in a search for planets has required the development of next-generation, high-contrast adaptive optics systems.
Science Recorder | Jonathan Marker | Wednesday, January 08, 2014
According to a January 7 news release from the Department of Energy’s Lawrence Livermore National Laboratory, the most advanced instrument for directly imaging and analyzing planets orbiting other stars is finally operational after almost 10 years of development, testing, and evaluation.
“Even these early first-light images are almost a factor of 10 better than the previous generation of instruments. In one minute, we were seeing planets that used to take us an hour to detect,” said Bruce Macintosh of Lawrence Livermore National Laboratory, who led the team that built the instrument.
Called the Gemini Planet Imager (GPI), the instrument will be used for high-contrast imaging to better study dim planets or dusty disks adjacent to bright stars. GPI is the first fully improved planet imager, designed for exoplanet imaging deployed on one of the world’s largest telescopes: the 8-meter Gemini South telescope in Chile.
Probing the environments of distant stars in a search for planets has required the development of next-generation, high-contrast adaptive optics (AO) systems, in which Livermore is a leader. These systems are sometimes referred to as extreme AO.
According to Macintosh, direct imaging of planets is difficult because planets such as Jupiter are a billion times dimmer than their parent stars. ”Detection of the youngest and brightest planets is barely within reach of today’s AO (high-contrast adaptive optics systems),” he said. ”To see other solar systems, we need new tools.”
GPI completed its first observations in November 2013. ”The GPI team’s huge amount of high quality work has begun to pay off and now holds the promise of many years of important science to come,” said LLNL Project Manager David Palmer.
During GPI’s first observations, it imaged earlier known planetary systems – the 4-planet HR8799 system and the Beta Pictoris system, amid others. GPI has also acquired the first spectrum of the young planet Beta Pictoris b.
“GPI’s performance requirements are extremely challenging,” said LLNL engineer Lisa Poyneer, who established the algorithms used to correct for atmospheric turbulence, and directed the testing of the AO system in the laboratory and on the telescope. ”As a result, the AO system features several original technologies that were designed specifically for exoplanet science. After years of development and testing, it is very rewarding to see the AO system operating so well and enabling these remarkable images.”
Capturing images of exoplanets is complementary to other exoplanet successes such as NASA’s Kepler mission, which is exceedingly sensitive to small planets close to their parent star and focuses on mature stars.
Re: At Least 8.8 Billion Earth-Size, Just-Right Planets Found, Study Says
Jan 14, 2014 01:26 PM EST By Russell Westerholm, UniversityHerald Reporter (r.westerholm@universityherald.com) Super-Earths Have Land Continents and Oceans, Making Them Much Similar to Earth Than Previously Thought
(Photo : Flickr/CC) Like Earth, the super-Earth model had oceans and bodies of land due to the shifting of tectonic plates."Super-Earths" were just recently found to be more common in the universe than previously known, but now the exoplanets are believed to be more Earth-like than ever.
Super-Earths get their name for having a similar makeup to our own planet and for being slightly larger as well. Recent studies have found them to exist more commonly in the universe and our own Milky Way Galaxy.
According to Space.com, a new study finds the tectonically active super-Earths have exposed continents of land surrounded by oceans. Like Earth, these exoplanets most likely store their water in the mantle, creating a stable environment similar to our planet.
"Super-Earths are expected to have deep oceans that will overflow their basins and inundate the entire surface, but we show this logic to be flawed," study researcher Nicholas Cowan said in a press release. "Terrestrial planets have significant amounts of water in their interior. Super-Earths are likely to have shallow oceans to go along with their shallow ocean basins."
Cowan, a postdoctoral fellow at Northwestern's Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), presented the study at the 223rd meeting of the American Astronomical Society last week.
For their study, Cowan and his colleagues created a model for water storage on these super-Earths. On Earth, the mantle is a rocky layer that accounts for the planet's mass and volume. On the super-Earth model, the larger mass and volume means a more powerful gravitational pull, but even with the enlarged size, the exoplanet still has a surface similar to Earth's.
"We can put 80 times more water on a super-Earth and still have its surface look like Earth," Cowan said in the release. "These massive planets have enormous seafloor pressure, and this force pushes water into the mantle."
For the model to be completed, the researchers will have to make up for two main inefficiencies. First, the model assumes the super-Earths have plate tectonics and, second, is assumes the water in the Earth's mantle, based on an estimate.
"These are the two things we would like to know better to improve our model," Cowan said in the release. "Our model is a shot from the hip, but it's an important step in advancing how we think about super-Earths."
Re: At Least 8.8 Billion Earth-Size, Just-Right Planets Found, Study Says
Earth may be cosmic odd-ball, astronomers say
Earth may be a cosmic fluke.
Earth may be cosmic odd-ball, astronomers say
Science Recorder | Delila James | Tuesday, January 14, 2014
NASA’s Kepler space telescope has located close to 150 confirmed exoplanets in 76 star systems and more than 3,000 that are as yet unconfirmed, according to Space.com. But so far none of them even remotely resemble Earth. Instead, the universe seems to be largely populated by hot, gas-enveloped super-Earths, which are the same size and up to four times larger than our temperate blue planet.
Super-Earths and mini-Neptunes, which are planets smaller than Neptune with thick hydrogen-helium atmospheres, seem to dominate the cosmic landscape, according to scientists at the annual meeting of the American Astronomical Society in National Harbor, Maryland. And they are nothing like Earth.
“Our solar system seems to be different,” said Yoram Lithwick of Northwestern University. “All these planets that Kepler has found, they are strange.”
According to Lithwick, 20 to 30 percent of all star systems have these “crazy planets.”
Super-Earths and mini-Neptunes that are more than two and a half times the radius of Earth “must be covered with lots and lots of gas, which is the most surprising result,” he said.
Lithwick has studied some 60 such exoplanets and found that they probably formed “very quickly after the birth of their star, while there was still a gaseous disk around the star.”
Earth, on the other hand, is thought to have formed later, after the gaseous disk had disappeared, Lithwick said.
Despite its name, a super-Earth would not be on the space traveler’s list of places to visit. These planets are much hotter than Earth and have extreme atmospheric pressures due to the tremendous amount of gas covering their rocky cores.
“It would be like being below 10 oceans here on Earth,” said Geoff Marcy of the University of California at Berkeley.
When asked if life could exist under such extreme conditions, Marcy told reporters he’d asked some of his biologist friends the same question. The short answer: they weren’t sure.
“It’s not impossible,” Marcy said. “We know very little about how life got started and in what environments it might flourish.”
The Kepler space telescope was launched in 2009 on a mission to find Earth-like planets by observing the dimming of light as they passed in front of, or transited, their stars. Even though the space observatory is no longer fully operational, during its lifetime it yielded a treasure trove of data, which scientists will be analyzing for years to come.
Over 75 percent of planets, NASA's Kepler spacecraft found vary in sizes from Earth to Neptune.(Photo : Reuters)
Over 75 percent of planets, NASA's Kepler spacecraft found vary in sizes from Earth to Neptune Clarksville Online reported Tuesday.
Kepler staff kept compiled information about exoplanet systems from four years of analysis from the earth Clarksville Online reported. The information was distributed at the American Astronomical Society's meeting in Washington D.C. Clarksville Online reported.
The information verified that the content Kepler found were planets, and equaled sizes similar to earth and Neptune which is four-times larger than planet Earth Clarksville Online reported.
"This marvelous avalanche of information about the mini-Neptune planets is telling us about their core-envelope structure, not unlike a peach with its pit and fruit," Geoff Marcy, professor of astronomy at University of California, Berkeley told Clarkville Online. "We now face daunting questions about how these enigmas formed and why our solar system is devoid of the most populous residents in the galaxy," Marcy told Clarksville Online. Marcy oversaw data examination for the Dual-Doppler Feasibility Study
Researchers identified 41 exo-planets, and the masses or body properties of 16 Clarksville Online reported. This allowed scientists to figure out how dense the planets were, categorize them as rocky or gaseous or both, and tell what chemicals they are made with Clarksville Online reported.
"Kepler's primary objective is to determine the prevalence of planets of varying sizes and orbits. Of particular interest to the search for life is the prevalence of Earth-sized planets in the habitable zone," said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center in Moffett Field, CA told Clarksville Online. "But the question in the back of our minds is: are all planets the size of Earth rocky? Might some be scaled-down versions of icy Neptunes or steamy water worlds? What fraction are recognizable as kin of our rocky, terrestrial globe? told Clarksville Online.
Neptune was known to have a rocky center Clarksville Online reported.
In 2011, the Kepler Space Telescope first spotted the planet known as Kepler-10c in the Draco constellation around 560 light-years from Earth. With a radius of about 14,500 km, a bit more than double that of the Earth's, it was initially believed that Kepler-10c was one of the small gas giant planets that are quite common in the galaxy. However, an analysis of the planet by the Harvard-Smithsonian Center for Astrophysics using the HARPS-N telescope on the Canary Islands found that Kepler-10c was in fact solid, and had a mass 17 times greater than the Earth. A solid planet like its neighbor Kepler-10b (also the very first terrestrial exoplanet discovered) but with a mass akin to that of Neptune and a significantly smaller radius, Kepler-10c is a very dense and rocky planet. This discovery is incredibly surprising as our current understanding of planet formation cannot adequately explain the existence of such a planet.
When planets form, the factor that causes terrestrial planets to diverge from their Jovian brothers is mass. Terrestrial planets like our Earth did not have a lot of material to form from during the early solar system. As such its mass remained fairly small, meaning that it did not have the gravitational pull to attract and retain gases such as hydrogen, helium, etc. Gas giants in our solar system formed beyond the Frost Line, meaning that hydrogen compounds such as water and ammonia could exist as ice and allowed the early Jovian planetesimals to increase in mass.
Kepler-10c is surprising as it has roughly the same mass as Neptune, but has not accumulated a thick atmosphere of hydrogen and helium. The fact that the planet is also around 2.3 times the size of the Earth is also astounding, as calculations in the past have suggested that gravity compresses rocky planets such that they cannot be greater than two times the size of the Earth. The planet is believed to be composed of the same materials as the Earth, such as silicates and iron, but with different proportions.
"All the major existing planetary formation models were not predicting this type of planet, and it is why we could not believe our result at the beginning," says Xavier Dumusque who presented their findings at the American Astronomical Society.
As a result of these discoveries, Kepler-10c has been dubbed a "Mega-Earth," signifying that is bigger and much more massive than previously discovered "Super-Earths," belonging in a new class of its own. Kepler-10c may not be alone though, as another astronomer presenting at the AAS, astronomer Lars A. Buchhave, found a correlation between the size of a planet at which it transitions from solid to gassy and its period around its star. This suggests that more Mega-Earths may be found as astronomers take into account these factors.
Kepler-10c's mass isn't the only thing that defies our current theories of planet formation; its age also has far-reaching repercussions. The planet formed when the universe was only 3 billion years old, a time when there should not have been enough material for a planet of such a size to form. The early universe was composed of almost entirely hydrogen and helium. First generation stars, as such, did not possess any "metals" (in astrophysics, a blanket term for any element not hydrogen or helium). These stars fused hydrogen and helium into heavier elements, and then seeded the universe with elements such as iron, silicon, carbon when they died and exploded in supernovae. It was believed that this process occurs over billions of years, meaning that there should not have been enough heavy elements for Kepler-10c to form from. Since Kepler-10c does exist, it shows that the early universe was in fact capable of producing such massive rocky planets.
"Finding Kepler-10c tells us that rocky planets could form much earlier than we thought. And if you can make rocks, you can make life," said physicist Dimitar Sasselov.
Astronomers sometimes exclude older stars when searching for Earth-like planets, under the presumption that such planets were unlikely to form. Since rocky, Earth-like planets are capable of being formed in old stars like Keper-10, they expand the pool of potentially life-bearing worlds that we have in our pursuit for Earth-like planets.
Astronomers hunting for another Earth have found what may be the closest match yet, a potentially rocky planet circling its star at the same distance as the Earth orbits the Sun, NASA said Thursday.
Not only is this planet squarely in the Goldilocks zone—where life could exist because it is neither too hot nor too cold to support liquid water—its star looks like an older cousin of our Sun, the US space agency said.
That means the planet, which is 1,400 light-years away, could offer a glimpse into the Earth's apocalyptic future, scientists said.
Known as Kepler 452b, the planet was detected by the US space agency's Kepler Space Telescope, which has been hunting for other worlds like ours since 2009.
"Kepler 452b is orbiting a close cousin of our Sun, but one that is 1.5 billion years older," NASA said in a statement.
Its star is four percent more massive than the Sun and 10 percent brighter.
If the planet is rocky, and scientists believe that it has a better than even chance of being just that, then it could be in the midst of a fearful scenario, as the heat from its dying star evaporates Kepler 452b's lakes and oceans.
"If Kepler 452b is indeed a rocky planet, its location vis-a-vis its star could mean that it is just entering a runaway greenhouse phase of its climate history," said Doug Caldwell, a Search for Extraterrestrial Intelligence (SETI) Institute scientist working on the Kepler mission.
There are 4,696 planet candidates now known with the release of the seventh Kepler planet candidate catalog - an increase of 521 since the release of the previous catalog in January 2015
"The increasing energy from its aging sun might be heating the surface and evaporating any oceans. The water vapor would be lost from the planet forever," he added.
"Kepler 452b could be experiencing now what the Earth will undergo more than a billion years from now, as the Sun ages and grows brighter."
Planetary catalog
The Kepler mission launched in 2009 to search for exoplanets, which are planets outside our solar system, particularly those about the size of Earth or smaller.
"Today, and thousands of discoveries later, astronomers are on the cusp of finding something people have dreamed about for thousands of years—another Earth," NASA said in a statement.
On Thursday, NASA released the latest catalog of exoplanet candidates, adding more than 500 new possible planets to the 4,175 already found by the space-based telescope.
"This catalog contains our first analysis of all Kepler data, as well as an automated assessment of these results," said SETI Institute scientist Jeffrey Coughlin.
The new catalog includes 12 candidates that are less than twice the diameter of Earth and which are orbiting in the habitable zones of their stars.
Of those 12 new candidates, Kepler 452b "is the first to be confirmed as a planet," NASA said.
Kepler identifies possible planets by watching for dips in the brightness of stars, which could be caused by a planet passing between the star and the telescope.
Other scientific tools are needed to judge whether the planet is gassy or rocky.
The Kepler mission has cost NASA about $600 million, and the US space agency said in 2013 that two of its orientation wheels had lost function, leaving the space telescope beyond repair.
But scientists have years to pore over the data it has returned in order to narrow the search for Earth-like worlds.
NASA will hold a news conference at 1 p.m. EST Wednesday, Feb. 22, to present new findings on planets that orbit stars other than our sun, known as exoplanets. The event will air live on NASA Television and the agency's website.
Details of these findings are embargoed by the journal Nature until 1 p.m.
Limited seating is available in the NASA TV studio for media who would like to attend in person at the agency’s Headquarters at 300 E Street SW in Washington. Media unable to attend in person may ask questions by telephone. To attend in person or participate by phone, media must send an email with their name, affiliation and telephone number to Dwayne Brown at dwayne.c.brown@nasa.gov by noon Feb. 22.
Media and the public also may ask questions during the briefing on Twitter using the hashtag #askNASA.
The briefing participants are:
· Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington
· Michael Gillon, astronomer at the University of Liege in Belgium
· Sean Carey, manager of NASA's Spitzer Science Center at Caltech/IPAC, Pasadena, California
· Nikole Lewis, astronomer at the Space Telescope Science Institute in Baltimore
· Sara Seager, professor of planetary science and physics at Massachusetts Institute of Technology, Cambridge
A Reddit AMA (Ask Me Anything) about exoplanets will be held following the briefing at 3 p.m. with scientists available to answer questions in English and Spanish.
For NASA TV streaming video, downlink and updated scheduling information, visit: http://www.nasa.gov/nasatv
Talk about lucky number seven. Astronomers have discovered not one, not two, but seven Earth-sized planets orbiting a star called TRAPPIST-1.
What’s more, three of them are in the habitable zone— the happy place where liquid water can exist on the surface of rocky planets, as it’s not too hot or cold. (Although liquid water could potentially exist on any of the seven, NASA said, it likes the odds on those three best.) The space agency calls the discovery of the fascinating solar system record-breaking.
“The discovery gives us a hint that finding a second Earth is not just a matter of if, but when,” Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA Headquarters, said at a news conference announcing the discovery.
Zurbuchen called it a "major step forward" towards the goal of answering the very big question: Is there life on other worlds?
The discovery "is very promising for the search for life beyond our solar system,” Michael Gillon, astronomer at the University of Liege in Belgium, added during the press conference.
This is the first time astronomers have found so many Earth-sized planets circling the same sun.
Zurbuchen called it a "major step forward" towards the goal of answering the very big question: Is there life on other worlds?
The discovery "is very promising for the search for life beyond our solar system,” Michael Gillon, astronomer at the University of Liege in Belgium, added during the press conference.
This is the first time astronomers have found so many Earth-sized planets circling the same sun.
The three planets in the habitable zone, also known as the Goldilocks Zone, are called TRAPPIST-1e, f, and g. Exoplanet “e” is about the same size as Earth and even gets around the same amount of star light as we do.
Scientists already knew of thousands of planets beyond our own solar system.
All told, the tally of confirmed exoplanets stood at 3,449 on Wednesday. But only a small number of discovered exoplanets meet the criteria for being possible Earths-- Earth-sized planets that are not too big, and in the habitable zone of a star.
While this discovery was made using the Spitzer Space Telescope, one of the most important instruments in the search for other planets is the Kepler Space Telescope, which is credited with 2,331 confirmed exoplanet discoveries. It uses a technique called the transit method, watching for a star to dim when a planet passes in front of the distant sun. About 74 percent of known exoplanets have been discovered using that method, according to NASA.
Exoplanet discoveries just keep coming.
Earlier this month, astronomers announced that they had evidence of perhaps as many as 114 new exoplanets; the data they used to find those came from Hawaii’s Keck Observatory, which made observations of over 1,600 stars for over two decades. One of those newly-discovered planets that has garnered attention is a hot, rocky “super Earth” called Gliese 411b.
Scientists have even discovered a planet orbiting the closest star to Earth, aside from the sun. Called Proxima b, that planet is somewhat larger than our own planet and lies about four light years away— close by cosmic standards but still incredibly far away from a human perspective. (One light year— the distance light can travel in one Earth year— equals almost 6 trillion miles.) The important Proxima b discovery was announced last August.
Re: At Least 8.8 Billion Earth-Size, Just-Right Planets Found, Study Says
Posted by Andrew Fazekas in StarStruck on December 4, 2013
NASA scientists found faint signatures of water in the atmospheres of five distant planets orbiting three different stars. All five planets appear to be hazy. Credit: NASA, ESA, A. Mandell (Goddard Space Flight Center), and D. Deming (University of Maryland, College Park)
To determine what’s in the atmosphere of an exoplanet, astronomers watch the planet pass in front of its host star and look at which wavelengths of light are transmitted and which are partially absorbed.
This image taken by the Gemini Planet Imager (GPI) shows a planet orbiting the star Beta Pictoris. In addition to the image, the GPI obtains spectral information from every pixel element in the field of view, allowing scientists to study the planet in great detail. Image credit: Gemini/Christian Marois, NRC Canada. January 07, 2014
Over 75 percent of planets, NASA's Kepler spacecraft found vary in sizes from Earth to Neptune.(Photo : Reuters)
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