In the past three decades, scientists have found more than 4,000 exoplanets. And the discoveries will keep rolling in; observations suggest that every star in the Milky Way galaxy hosts more than one planet on average.
By Leonard David
www.space.com
11-26-19
Given a convergence of ground- and space-based capability, artificial intelligence/machine learning research and other tools, are we on the verge of identifying what is universally possible for life — or perhaps even confirming the existence of extraterrestrial intelligence?
Scientists develop astrocomb, a tool that will find Earth-like planets, alien life
Scientists have developed an astrocomb, a tool that precisely measures frequencies or colours of light, which can help widen the search for Earth-like planets, and perhaps extraterrestrial life.
By The Week
2-21-19
The custom-made frequency comb, developed by researchers from National Institute of Standards and Technology's (NIST) in the US, provides the precision needed for discovering and characterising planets orbiting M dwarf stars, which comprise 70 per cent of the stars in the galaxy and are plentiful near Earth.
The European Space Agency’s Science Programme Committee has approved the Planetary Transits and Oscillations of stars (PLATO) mission to move into the construction phase. They aim to launch this deep-space observatory in 2026 with the goal of “discovering and
By Tom Ward
futurism.com
7-4-17
characterizing Earth-sized planets and super-Earths orbiting Sun-like stars in the habitable zone” — although it “could eventually lead to the detection of extraterrestrial life,” according to a University of Warwick press release.
The observatory will have 26 telescopes on board and will be launched 1.5 million km (932,000 miles) into space, where, according to a mission summary, it will conduct “Ultra-high precision, long (up to several years), uninterrupted photometric monitoring in the visible band of very large samples of bright (mV ≤11) stars.” This will provide unprecedented data on distant planets.
NASA will announce the latest crop of planet discoveries from the Kepler Space Telescope during a briefing Monday morning (June 19).
The briefing will be at 11 a.m. EDT (1500 GMT) during the Kepler
BY Jesse Emspak
Space.com
6-18-17
Science Conference at NASA's Ames Research Center in California. You can watch the exoplanet announcement here, courtesy of NASA TV. NASA will livestream the conference here: http://www.nasa.gov/live.
NASA announced the discovery of seven Earth-sized planets around a star about 40 light years away from Earth. All seven could have water, which is key to life like ours, and three of them fall in the habitable zone.
CBS News
2-23-17
Michio Kaku, CBS News science and futurist contributor and physics professor at the City University of New York, joins "CBS This Morning" with more on this new discovery.
This illustration shows the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Scientists using the Spitzer Space Telescope and ground-based telescopes have discovered that there are seven Earth-size planets in the system.
NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.
By NASA
2-22-17
The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
Seven Earth-sized planets have been observed by NASA's Spitzer Space Telescope around a tiny, nearby, ultra-cool dwarf star called TRAPPIST-1. Three of these planets are firmly in the habitable zone. Credits: NASA
At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.
This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system. Assisted by several ground-based telescopes, including the European Southern Observatory's Very Large Telescope, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
The new results were published Wednesday in the journal Nature, and announced at a news briefing at NASA Headquarters in Washington.
Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them, allowing their density to be estimated.
Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated – scientists believe it could be an icy, "snowball-like" world, but further observations are needed.
"The seven wonders of TRAPPIST-1 are the first Earth-size planets that have been found orbiting this kind of star," said Michael Gillon, lead author of the paper and the principal investigator of the TRAPPIST exoplanet survey at the University of Liege, Belgium. "It is also the best target yet for studying the atmospheres of potentially habitable, Earth-size worlds."
This artist's concept shows what each of the TRAPPIST-1 planets may look like, based on available data about their sizes, masses and orbital distances.
Credits: NASA/JPL-Caltech
In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky.
The planets may also be tidally locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes.
Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. In the fall of 2016, Spitzer observed TRAPPIST-1 nearly continuously for 500 hours. Spitzer is uniquely positioned in its orbit to observe enough crossing – transits – of the planets in front of the host star to reveal the complex architecture of the system. Engineers optimized Spitzer’s ability to observe transiting planets during Spitzer’s “warm mission,” which began after the spacecraft’s coolant ran out as planned after the first five years of operations.
"This is the most exciting result I have seen in the 14 years of Spitzer operations," said Sean Carey, manager of NASA's Spitzer Science Center at Caltech/IPAC in Pasadena, California. "Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets.”
Following up on the Spitzer discovery, NASA's Hubble Space Telescope has initiated the screening of four of the planets, including the three inside the habitable zone. These observations aim at assessing the presence of puffy, hydrogen-dominated atmospheres, typical for gaseous worlds like Neptune, around these planets.
This 360-degree panorama depicts the surface of a newly detected planet, TRAPPIST 1-d, part of a seven planet system some 40 light years away. Explore this artist’s rendering of an alien world by moving the view using your mouse or your mobile device. Credits: NASA
In May 2016, the Hubble team observed the two innermost planets, and found no evidence for such puffy atmospheres. This strengthened the case that the planets closest to the star are rocky in nature.
"The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets," said Nikole Lewis, co-leader of the Hubble study and astronomer at the Space Telescope Science Institute in Baltimore, Maryland. NASA's planet-hunting Kepler space telescope also is studying the TRAPPIST-1 system, making measurements of the star's minuscule changes in brightness due to transiting planets. Operating as the K2 mission, the spacecraft's observations will allow astronomers to refine the properties of the known planets, as well as search for additional planets in the system. The K2 observations conclude in early March and will be made available on the public archive.
Spitzer, Hubble, and Kepler will help astronomers plan for follow-up studies using NASA's upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone, and other components of a planet's atmosphere. Webb also will analyze planets' temperatures and surface pressures – key factors in assessing their habitability.
NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate. Science operations are conducted at the Spitzer Science Center, at Caltech, in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.
Life on other planets would likely be brief and become extinct very quickly, say astrobiologists from ANU Research School of Earth Sciences.
In research aiming to understand how life might develop, the scientists realised new life would commonly die out due to runaway heating or cooling on their fledgling planets.
"The universe is probably filled with habitable planets, so many scientists think it should be teeming with aliens," said Dr Aditya Chopra, lead author on the paper, which is published in Astrobiology.
"Early life is fragile, so we believe it rarely evolves quickly enough to survive." [...]
The revamped Kepler mission is raking in the discoveries, turning up new kinds of worlds.
After being crippled by a mechanical malfunction, NASA’s planet-hunting Kepler spacecraft is back in action and has found a slew of planets orbiting other stars.
Called K2, the revamped mission has already found more than 100 confirmed planets, the University of Arizona’s Ian Crossfield announced Tuesday at a conference of the American Astronomical Society. Some of these are very different from what the spacecraft observed during its original mission; many are in multi-planet systems and orbit stars that are brighter and hotter than the stars in the original Kepler field.
It has found a system with three planets that are bigger than Earth, spotted a planet in the Hyades star cluster—the nearest open star cluster to Earth—and discovered a planet being ripped apart as it orbits a white dwarf star.
Scientists have also found 234 possible planets that are awaiting confirmation, said Andrew Vanderburg of the Harvard-Smithsonian Center for Astrophysics.[...]
At the edges of our galaxy, 100,000 light-years away, massive, dense clusters of stars glom together like a humongous interstellar house party. This is where, according to astrophysicists from the Harvard-Smithsonian Center for Astrophysics, we might find intelligent alien life.
The CFA's lead author, Rosanne DiStefano made this hypothesis at a meeting of the American Astronomical Society on Wednesday, and — believe it or not — her logic checks out.
Let's say finding intelligent life is a hypothetical one-in-a-million chance. By the center's estimation, there are 150 globular clusters in our Milky Way galaxy, each holding roughly a million stars per 100 million light years. Plus, they're old — like, 10 billion years old — and stable, meaning they didn't get nailed by cataclysmic, planet-destroying gamma-ray bursts.
It could be that these globular clusters are full of planets twice as old as our own, that had billions more years to develop. The Fermi paradox, a theory of why alien life hasn't found us yet, refers to these clusters as Planet X. [...]
The pull of gravity on a distant star can now be measured more accurately, shedding light on other worlds, say astronomers.
The method makes it possible to study even the faintest of stars.
"Our technique can tell you how big and bright is the star, and if a planet around it is the right size and temperature to have water oceans, and maybe life," said Prof Jaymie Matthews.
Artist's illustration of planets forming in a circumstellar disk like the one surrounding the star LkCa 15. The planets within the disk's gap sweep up material that would have otherwise fallen onto the star.
By Mike Wall
Space.com
11-18-15
For the first time ever, astronomers have directly observed planets in the process of being born.
Scientists have photographed a gas-giant exoplanet forming around a young star called LkCa 15, which lies about 450 light-years from Earth.
"It's exciting, because it's the first time that we've been able to image forming planets directly," study lead author Stephanie Sallum, a graduate student at the University of Arizona, told Space.com. "It gives us a system to follow up in the future, in depth, to really understand the details of how planets form." [...]
Aliens should exist, given the number of planets in the universe with the potential for supporting life - but the absence so far of any confirmed extraterrestrial contact has puzzled scientists for a long time.
An Oxford professor of astrophysics explains what's going on.
Astronomers estimate there are at least 17 billion Earth-like planets in the Milky Way galaxy - which itself is made up of 100 billion stars. And many of these rocky planets exist in the "Goldilocks" zone, that is, they are not too hot and not too cold to have liquid water.
The discovery of water on Mars has lent weight to the idea that alien life does exist on other planets. Scientists, like Oxford University astrophysics Professor Chris Lintott, believe bacteria is now likely to be found on the Red Planet, which Professor Lintott told Nine To Noon once had much, much more H20 on it.
"The old days of aliens wandering around Mars have been put to rest, but that's why it's interesting.
"Mars is sort of right on the edge, it's a marginal case, it's probably right on the edge of just being warm enough to sometimes have liquid water.
"We know it had lots of water in the past, it had oceans and lakes which have evaporated over the eons and over billions of years... So if life got started on Mars and in particular if life clung on on Mars as well, then that suggests it's likely that it's got a foothold everywhere in the universe." [...]
An artist's concept of a planetary lineup, featuring five exoplanets that may be similar to Earth: (L to R) Kepler-22b, Kepler-69c, Kepler-452b, Kepler-62f and Kepler-186f, with Earth on the far right. With more advanced telescopes, scientists may be able to find signs of life on exoplanets like these.
By Calla Cofield
Space.com
8-3-15
The search for life elsewhere in the universe is on the cusp of a new era: When scientists will have the opportunity to study the atmospheres of potentially habitable planets with future, technologically advanced telescopes. Humans have no foreseeable way to travel to these worlds to study them up close, but the chemical mixtures that surround them may reveal the presence of life.
There is no single "smoking gun" for life; no atmospheric mixture that can definitively declare, "Something lives here!" (At least, not that scientists know of). And searching for life from afar carries a heavy burden of proof: Any signal that looks like life could actually be created in some clever, non-biological process that scientists haven't yet thought of.
So, in addition to coming up with ideas for what life might look like on alien planets, scientists must also come up with ways that non-living processes could create those same signatures. Scientists are now working hard to think up new examples of these "false positives," in an effort to avoid a misstep when the data start to appear. . . .
Extra-terrestrial life does exist, the head of Nasa has confirmed, but said aliens were not hidden in Area 51.
Nasa Administrator Major Charles Bolden told British schoolchildren that he was confident that scientists would find life outside of Earth because there were so many planets that are similar to our own.
Asked by 10-year-old Carmen Dearing if he believed in aliens, he said: "I do believe that we will someday find other forms of life or a form of life, if not in our solar system then in some of the other solar systems - the billions of solar systems in the universe.
“Today we know that there are literally thousands, if not millions of other planets, many of which may be very similar to our own earth. So some of us, many of us believe that we're going to find...evidence that there is life elsewhere in the universe."
Major Bolden also admitted that Area 51 existed but said the US government was not hiding alien life there.
NASA is taking the hunt for life on other worlds to the next level.
The space agency has assembled a team of experts from across scientific fields at some of the nation's leading universities and research institutes to see if any of the more than 1,000 planets discovered outside our solar system may be habitable.
The initiative is called Nexus for Exoplanet System Science (NExSS), and it brings together earth scientists, planetary scientists, heliophysicists and astrophysicists.
“This interdisciplinary endeavor connects top research teams and provides a synthesized approach in the search for planets with the greatest potential for signs of life,” Jim Green, NASA’s Director of Planetary Science, said in a news release. “The hunt for exoplanets is not only a priority for astronomers, it’s of keen interest to planetary and climate scientists as well.”
The move comes just weeks after NASA's top scientist predicted that mankind will soon find indications of life outside of Earth. . . .
By Jessica Orwig
www.businessinsider.com.au
3-29-15
One of humanity’s biggest questions is “Are we alone?”
But is that still the right question?
Astronomers have confirmed over 1,800 exoplanets in our galaxy and estimate that there are around 100 billion in total
. Abuut 50 of these seem to be habitable. So, chances are good that we are not alone.
A better question for the new age is: If ET exists, what should we do about it?
That’s what scientists at the Search for Extraterrestrial Intelligence (SETI) Institute discussed last month at the annual American Association for the Advancement of Science meeting.
SETI is famous for its series of telescopes that search the skies for messages that look like they could be sent by intelligent extraterrestrial beings. But so far the cosmos has been quiet.
And after 50 years of listening, some of the folks at SETI are starting to say it’s high time for a change to the way we search. . . .
Five rocky alien worlds that are 80 percent as old as the universe itself have been discovered, suggesting that Earth-size planets have been a feature of the Milky Way galaxy almost since its beginning.
The new found exoplanets circle Kepler-444, an 11.2-billion-year-old star about 25 percent smaller than the sun that lies 117 light-years from Earth. All of the worlds are Venus-size or smaller and are therefore rocky, though scientists know nothing else about their composition.
All five alien planets complete an orbit in less than 10 days, meaning they're almost certainly too hot to support life as we know it. But Kepler-444 hints at the existence of other ancient planetary systems that may be more hospitable, researchers said. . . .
A new alien-planet–hunting telescope has just come online in Chile, and it could help scientists peer into the atmospheres of relatively small planets circling nearby stars.
The Next-Generation Transit Survey (NGTS for short) — located at the European Southern Observatory's (ESO) Paranal Observatory — is designed to seek out planets two to eight times the diameter of Earth as they pass in front of their stars. Such a planet will cause the light of the star to dip ever so slightly when passing in front of it, allowing the telescope to detect the planet during its transit.
"We are excited to begin our search for small planets around nearby stars," Peter Wheatley, an NGTS project lead from the University of Warwick, U.K., said in as statement. "The NGTS discoveries, and follow-up observations by telescopes on the ground and in space, will be important steps in our quest to study the atmospheres and composition of small planets such as the Earth." . . .
NASA's Kepler spacecraft has discovered its 1,000th alien planet, further cementing the prolific exoplanet-hunting mission's status as a space-science legend.
Kepler reached the milestone today (Jan. 6) with the announcement of eight newly confirmed exoplanets, bringing the mission's current alien world tally to 1,004. Kepler has found more than half of all known exoplanets to date, and the numbers will keep rolling in: The telescope has also spotted 3,200 additional planet candidates, and about 90 percent of them should end up being confirmed, mission scientists say.
Furthermore, a number of these future finds are likely to be small, rocky worlds with temperate, relatively hospitable surface conditions — in other worlds, planets a lot like Earth. (In fact, at least two of the newly confirmed eight Kepler planets — which were announced in Seattle today during the annual winter meeting of the American Astronomical Society — appear to meet that description, mission team members said.)
Air pollution is clogging the skies of our planet. Now one scientist thinks Earth may be just one of many polluted worlds — and that searching for extraterrestrial smog may actually be a good way to search for alien intelligence.
"People refer to 'little green men,' but ETs that are detected by this method should not be labeled as green," says Avi Loeb, an astronomer at Harvard University.
The idea of finding alien polluters may be a bit of a long shot, but Loeb says it's possible.
Astronomers have been able to glimpse the atmospheres of planets outside our solar system for a while now. In 2018, NASA will launch the James Webb Space Telescope, which will be larger and better than ever at looking at extrasolar atmospheres.
"The idea would be that when a planet like the Earth is passing in front of its host star, a small fraction of the light from the star would pass through the atmosphere and show potentially evidence for these pollutants," he says. . . .
