Tag Archives: exoplanets

Kepler Space Telescope Discovers More Potentially Habitable Planets

Yesterday researchers from the NASA’s Kepler Space Telescope announced the discovery of 833 more candidate planets, 104 of which have the potential to harbor life. Included in that 104 in their respective Goldilocks Zones are 10 that are roughly the same size as Earth. As of this announcement, the total number of exoplanets discovered by Kepler since its launch in 2009 is now at 3,538. Its mission is to explore exoplanets and discover which ones are similar in size to Earth and are capable of supporting life. The announcement is coming from Kepler Science Conference, which is hosting over 400 scientists representing 30 countries.


According to William Borucki, the principal investigator for Kepler’s science mission, these discoveries “[open] a new era of exploration of our galaxy.” The first potentially habitable planet was announced two years ago, and since astronomers now believe there that most stars in the galaxy have at least one planet there is the possibility of many more potentially life-harboring discoveries to come.


This spring, Kepler’s mission was changed when two out of the four wheels used to point the telescope toward its targets broke, and NASA scientists were unable to repair them. Kepler completed its initial mission in 2012, and is currently completing an extended mission. Despite this, there is still a full year’s worth of data that has not been processed yet as Kepler monitored 150,000 stars and recorded data once every half hour for those four operational years. 


One analysis of Kepler’s data suggests that around 20% of sun-like stars have an Earth-like planet. So far, there have not been any reports of any such planet that completely mirrors Earth in terms of habitability and revolution length around a star like ours, but astronomers will continue to search. 

Read more: http://www.iflscience.com/space/kepler-space-telescope-discovers-more-potentially-habitable-planets

Exozodiacal Light Could Hinder Direct Imaging of Earth-Like Exoplanets

Finding life on exoplanets in a star’s habitable zone would, arguably, be the biggest event that has ever happened in human history. Unfortunately, an international team of astronomers using the Very Large Telescope discovered exozodiacal light around nearby stars, which would make imaging Earth-like exoplanets in those systems quite difficult. Steve Ertel from ESO and the University of Grenoble in France was lead author of the paper, which was published in the journal Astronomy & Astrophysics

Zodiacal dust can be generated by comet disintegration, collisions between asteroids or small planetary bodies, and through general space weathering of these bodies. When the tiny dust particles reflect sunlight or become heated enough to glow on their own, it produces a faint white light that can be widely seen throughout the solar system. When this phenomenon occurs in solar systems outside of our own, it’s called exozodiacal dust. 

Ertel’s team studied the exozodiacal dust near the habitable zones of 92 nearby stars, including 14 known to have exoplanets. Observations were made in near-infrared wavelengths using the Very Large Telescope’s Interferometer (VLTI). In order to produce a contrast high enough to view the dust, the VLT was given additional light from the four 1.8 meter Auxiliary Telescopes, allowing it to be ten times more powerful than any other similar instrument in the world. 

“If we want to study the evolution of Earth-like planets close to the habitable zone, we need to observe the zodiacal dust in this region around other stars,” Ertel said in a press release. “Detecting and characterizing this kind of dust around other stars is a way to study the architecture and evolution of planetary systems.”

Radiation from the star tends to push the tiny particles of zodiacal dust away, and a disc is formed past the habitable zone. It was assumed that the amount of dust in the clouds would decrease as the star and its system grew older, as there would be fewer asteroids to collide and create the dust. Interestingly, the stars with the brightest exozodiacal light came from older stars.

This blinding exozodiacal light could be problematic for future studies of each star’s potential planetary system. As if the glare from the star’s light wasn’t bad enough, the dust exacerbates that glare, becoming 1000 times brighter than zodiacal light in our solar system. The 14 stars known to have exoplanets all have extremely bright exozodiacal dust near the habitable zone, which will make it very difficult to directly image those planets. Further studies of the dust are needed to better understand its properties. This is necessary to find a way to circumvent it in order to image potential Earth-like planets in the habitable zone.

“The high detection rate found at this bright level suggests that there must be a significant number of systems containing fainter dust, undetectable in our survey, but still much brighter than the Solar System’s zodiacal dust,” adds co-author Olivier Absil from the University of Liège in Belgium. “The presence of such dust in so many systems could therefore become an obstacle for future observations, which aim to make direct images of Earth-like exoplanets.”

Read more: http://www.iflscience.com/space/exozodiacal-light-could-hinder-direct-imaging-earth-exoplanets

Asteroid Spaceship And Fusion-Powered Pluto Orbiter Among New Funded NASA Projects

Managinga space agency requires being constantly at the forefront of science and technology, so for the last 18 years NASA has invested incutting-edge projects that make up the NASA Innovative Advanced Concepts (NIAC) program.

For 2016, NASA has selected 13 projects for the NIAC Phase I, which will test pioneering technologies for planetary exploration and long-distance astronomy. Each project will receive about $100,000 for nine months to support the initial definition and feasibility of these concepts.

The latest NIAC selections include a number of concepts for planetary and robotic exploration, said Steve Jurczyk, NASAs associate administrator for the Space Technology Mission Directorate in Washington, in a statement. NASA continues to value early stage concept studies for our future missions.

The projects vary in scope and breadth. Among themaretwo interesting ideas for icy moon exploration. The first, called NIMPH, focuses on a tiny lander that would collect a surface sample, convert materials into propellant, and lift off from Europa (or another icy moon) to then fly back to Earth. The second idea takes a page out of Jules Verne’s book and focuses on a tethered rover that wouldclimb down a cryovolcano and deploy a submarine to explore Enceladus or Europa’ssubsurface ocean.

The rest of Phase I concepts havea good share of innovative technologies. Theres TANDEM, a new lightweight landing system;acurious concept calledBrane Craft, an ultra-thin spacecraft that could be used to remove orbital debris at a fraction of the current cost; andProject RAMA, which wouldturn asteroids into automatic spaceships and move them out of dangerous orbits, or take them closer to Earth to be mined.

Artists depictionof the TANDEM concept.Included is thedeployable heat shield and tensegrity structure for high-risk landing zones during extreme environmental missions.Virginia Polytechnic Institute and State University

Planets are also on the target list. Venus has only been explored by a handful of probes due to its surface temperature, which is high enough to melt electronics. For this reason, scientists are looking into AREE, a mechanical lander that would collectsamplesand send them back using transport balloons. Another venus-focused project is VIP-INSPR, which wouldexplore how to generate power on Venus using its toxic atmosphere.

NASAs Journey to Mars could also come to benefit from some of these projects. Theres a project focused on planning the most cost-efficient way for crew and cargo to get to Mars, and another looking for a way to harness microorganisms to use the Martian environment to recycle and print electronics.

The New Horizons and Dawn missions have also brought focus to the smaller but numerous objects in the Solar System. A laser-armed probecould be employed to study the composition of smaller objects from orbit, whileelectrically charged gliderscould use atmospheric plasma to fly around comets and asteroids.In addition, Pluto could receive an orbiter and lander powered by nuclear fusion.

The final project looks at the echo fromthe periodic oscillation of stars due to gravitational interactions with their planets. This technique could provide continent-level imaging of exoplanets, and it would be more cost effective than current imaging technologies.

The 2016 NIAC Phase I competition was fierce, as usual. All of the final candidates were outstanding, and limiting the choice to what fit in our budget was difficult, said Jason Derleth, NIAC program executive, in the statement. We hope each new study will push boundaries and explore new approaches thats what makes NIAC unique.

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Read more: http://www.iflscience.com/space/nasa-has-selected-its-advance-concept-projects-2016

New Tool Could Help Us Find Earth-like Planets

Looking for exoplanets is a painstakingly precise job. Scientists look for indirect features in their parent stars and then keep an eye on the most promising objects in the hope of confirming a detection. Given the difficulty of this task, astronomers are always looking for ways of improving the observations.

The latest innovation is a calibration tool called a laser frequency comb, an instrument that acts like a ruler against which astronomers can measure the light of the stars with incredible precision. The tool was developed by a team from Caltech, and they are confident that it will allow for a more detailed characterization of exoplanets. They describe their work in the journalNature Communications.

Dont think this is a physical comb like you use in your hair, though. Instead, evenly spaced lines of light act like the teeth of a comb, like tick marks on a ruler, against which the light from a distant star can be examined, all at a microscopic scale.

Traditionally, laser combs use pulses of light, but the Caltech team used a microwave-modulated continuous laser source, producing tick marks 10 to 100 times wider than other combs.Any wobbles in the light from the star, such as from an orbiting planet, would be detectable by noticing the fluctuations against the ticks. The team said this could be useful for finding planets of all shapes and sizes, even ones similar to Earth.

The instrument isnt limited to one telescope, either. It could be used in a variety of observatories, allowing light from a distant star to be analysed and detect the presence of a planet, when other methods might struggle.

The spectrum of a cool star and the spectrum of the comb.Small shifts of the spectrum relative to the stable wavelength standard provided by the laser comb would yield a precision measurement, and help with the detection of habitable exoplanets. Yi et al./Caltech

“We believe members of the astronomical community could greatly benefit in their exoplanet hunting and characterization studies with this new laser frequency comb instrument,” saidXu Yi, a graduate student in Vahala’s lab and the lead author of the paper, in astatement.

Precision rulers help astronomers to characterize periodic changes in a stars motion. If theres an orbiting planet, a star wobbles, and by measuring the size of said wobble, scientists can infer the mass and orbital distance of the planet. Without these details, its not possible to assess if a planet is habitable or not.

The instrument has been tested both at NASA’s Infrared Telescope Facility and with the Near Infrared Spectrometer on the W. M. Keck Observatory’s Keck II telescope. The comb worked without problems in both tests, and the team believe that the technology is ready to go.

“Our goal is to make these laser frequency combs simple and sturdy enough that you can slap them onto every telescope, and you don’t have to think about them anymore,” addedpaper coauthor Charles Beichman,executive director of the NASA ExoPlanet Science Institute at Caltech.

“Having these combs routinely available as a modest add-on to current and future instrumentation really will expand our ability to find potentially habitable planets, particularly around very cool red dwarf stars.

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Read more: http://www.iflscience.com/space/new-tool-could-help-us-find-earth-planets

Planet-Forming Disc Found To Be Colder Than Expected

Astronomers observing a distant planet-forming disk of dust and gas have found that it ismuch colder than expected. The findings, published in Astronomy & Astrophysics Letters, could have implications for how planetary systems form.

This research was carried out by an international team led by Stephane Guilloteau at the Laboratoire d’Astrophysique de Bordeaux, France. They studied the young star 2MASS J16281370-2431391, located 400 light-years from Earth, which is surrounded by a protoplanetary disk.

These disks are formed in the early stages of a planetary system; a similar diskof dust and gas gave rise to the planets, moons, and other bodies in our own Solar System. And with advances in telescopes, we are starting to get better and better at observing other disks in our galaxy.

This particular disk, nicknamed the Flying Saucer for its appearance, proved to be rather unusual. Most models predict that the temperature of dust grains in such disks should be between -258 and -253C (absolute zero is -273.15C). This disk, though, had grains at a much colder temperature of -266C, at a distance about 15 billion kilometers (9 billion miles) from the star.

It might seem like a minor difference, but there are some intriguing implications. Namely, it means the dust grains may have different properties than those expected. For example, a colder temperature may mean the grains are larger, which suggests the disks could grow to huge masses, allowing for the formation of a range of planets at all distances from the stars including giant planets in close orbits, something we have a lot of evidence for but no solid explanation for their formation.

To work out the impact of this discovery on diskstructure, we have to find what plausible dust properties can result in such low temperatures, said study coauthorEmmanuel di Folco in a statement. We have a few ideas for example, the temperature may depend on grain size, with the bigger grains cooler than the smaller ones. But it is too early to be sure.

These results were obtained by combining measurements from the Atacama Large Milimeter/submillimeter Array (ALMA) in Chile and the IRAM 30-meter telescope in Spain.

Read more: http://www.iflscience.com/space/planet-forming-disc-found-be-colder-expected

Titan’s Sunsets Give Insight To Hazy Atmospheres of Exoplanets

Certain characteristics of exoplanets can be difficult to study due to their atmospheres obscuring details. NASA scientists have begun to Saturn’s moon Titan at sunset, in the hope that it will help them to understand the haze from the atmosphere and what it could reveal about surface conditions. The study was led by Tyler Robinson of NASA’s Ames Research Center and the paper was published in the Proceedings of the National Academy of Sciences.

An atmosphere can act like a prism, separating light that passes through it into a spectrum of its components. The result of this spectrum provides information about the planetary body’s atmospheric composition, temperature, and structure, giving clues about its habitability. For exoplanets, this information is obtained as it transits its parent star. The light that goes through the atmosphere isn’t much different, but different enough to obtain meaningful information.

Titan’s atmosphere produces a haze just like an exoplanet, and it is strongest at sunset. The Cassini orbiter, which has been studying Saturn up close since 2004, has also gathered a considerable amount of information about Titan. By comparing information about Titan from when it produces the heaviest amount of haze versus when the haze is not as strong, scientists will be able to clarify findings and refine techniques used on exoplanets.

“Previously, it was unclear exactly how hazes were affecting observations of transiting exoplanets,” Robinson said in a press release. “So we turned to Titan, a hazy world in our own solar system that has been extensively studied by Cassini.”

The heavy haze created by Titan, and presumably many exoplanets as well, may overcomplicate some of the spectral information collected by researchers. However, many models currently used by astronomers tend to err on the side of being overly simplified due to constraints of computing power. For this study, the researchers analyzed four instances of Titan’s haze, using Cassini’s visual and infrared mapping spectrometer instrument. 

They found that the haze makes it very difficult to collect information about anything beyond the uppermost layer of the atmosphere. Titan’s lack of gravity (when compared to Earth) allows its atmosphere to extend out about 600 km (370 miles) around it. However, the haze only allows instruments to detect the upper 150-300 km (90-190 miles). This prohibits scientists from gathering information about the lower parts of the atmosphere, which is more dense and has complex attributes.

“People had dreamed up rules for how planets would behave when seen in transit, but Titan didn’t get the memo,” said co-author Mark Marley. “It looks nothing like some of the previous suggestions, and it’s because of the haze.”

The team also found that the haze was more likely to block out blue light, which has a shorter wavelength. This could have considerable implications for previous analyses of exoplanets, as current models are based on the assumption that all wavelengths in the visible spectrum would be equally affected. 

The technique used on Titan could also be applied to Mars and Saturn. Using the information gathered from within our own solar system in the search for exoplanets greatly extends the usefulness of the orbiters and will allow scientists to gather more information about other worlds in the Universe.

Read more: http://www.iflscience.com/space/titan%E2%80%99s-sunsets-give-insight-hazy-atmospheres-exoplanets

Kepler Finds 100 New Exoplanets

Everyone can get a second chance, even broken space telescopes. Kepler, the planet hunting telescope, suffered a critical malfunction to its stabilizing system in May 2013. It seemedit was the end for the mission, but thanks to the clever men and women at mission control, they managed to reconfigure the probe and keep the search for exoplanets going.

Thissecond phase, called K2, discovered its first exoplanet at the end of 2014, and this week it was announced at the 227thAmerican Astronomical Society Meeting that 100 new exoplanets have now been discovered.

K2 campaigns run for about 80 days at atime, focusingon a particular patch of the sky, with five campaigns having run so far. “This is a validation of the whole K2 program’s ability to find large numbers of true, bona fide planets,” Ian Crossfield, an astronomer at the University of Arizona, said when presenting the results, as reported by Space.com.

Kepler has observed 60,000 stars and found 7,000 transit-like signals since it was restarted. The telescope uses the transit method to discover new planets. The spacecraft is sensitive enough to detect small dips in the brightness of stars and if the dips are repeated with regularity, that is an indication that a planet is orbiting that object.

This method requires extremely precise pointing; thus, the spacecraft had four stabilizing reaction wheels. Kepler only needed three to function so it was not a huge issue when one stopped functioning threeyears into the mission. When the second stopped working almost a year later, the situation seemed dire.

Luckily they were able to come up with a clever solution. Photons, particles of light, can apply a force to an object. This phenomenon, called radiation pressure, together with the other two stabilizers, was used to keep the telescope in position.

Kepler has been the most prolific planet-hunting mission to date, discovering over 1,000 exoplanets, and it looks like it will be able to see many more in the years to come.

[H/T: Space.com]

Read more: http://www.iflscience.com/space/kepler-back-and-brings-100-new-exoplanets

NASA Saves Kepler Spacecraft After Unknown Emergency Left It Stranded

NASAs planet-hunting Kepler spacecraft has been saved from disaster after an unknown problem left it floating helplessly in space 120 million kilometers (75 million miles) from Earth.

At the end of last week, NASA announced that Kepler had gone into a fail-safe Emergency Mode (EM) due to an unknown problem with the space telescope, leaving engineers rushing to findthe source of the problem over the weekend.

“During a scheduled contact on Thursday, April 7, mission operations engineers discovered that the Kepler spacecraft was in Emergency Mode (EM),” NASA said in astatement. “EM is the lowest operational mode and is fuel intensive. Recovering from EM is the team’s priority at this time.”

But now the agency has announced that Kepler has recovered. Unfortunately,the cause of the problem is still not clear, so Kepler is not completely out of the woods yet. The spacecraft reached a stable state on Sunday morning and has since switched into a low fuel-burn mode. Scientists will investigate the spacecraft this week to try and work out what the problem was.

“The anomalous EM event is the first that the Kepler spacecraft has encountered during its seven years in space,” NASA said in its latest statement, adding that mission operations “remain vigilant”.

NASA first detected the problem towards the middle of last week, when scientists had been trying to point the spacecraft towards the middle of the Milky Way for a new round of observations.Owing to the serious nature of the issue, NASA allocated the Kepler team priority access to the Deep Space Network, the Earth-based communications network used to talk to spacecraft around the Solar System. Even using this, though, back-and-forth communication with the spacecraft took 13 minutes, owing to its distance from Earth.

Kepler 452b is the most Earth-like planet found by Kepler to date.NASA/JPL-Caltech/T. Pyle

Kepler was initially launched in 2009 to find planets beyond the Solar System using the transit method observing the dip in distant stars as planets passed in front. Via this method,the spacecraft has found thousands of potential exoplanets, far more than every other planet-hunting telescope combined. Understandably, then,NASA is pretty keen to keep the successful mission going, at least until its successor the Transiting Exoplanet Survey Satellite (TESS) launches in 2017.

This is not the first time Kepler has encountered a bit of a setback, though. In July 2012, one of the four gyroscopic reaction wheels used to orientate the spacecraft failed, meaning scientists had to devise an ingenious solution to use pressure from solar wind to act as a makeshift fourth wheel.

Thanks to these efforts, the spacecraft was able to resume operations as part of the K2 mission in 2014, continuing to find planets beyond the Solar System. Earlier this year, 100 new planets were reported as part of this secondary mission.

And now, Kepler’s groundbreaking mission can hopefully continue.

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Read more: http://www.iflscience.com/space/NASA-Kepler-spacecraft-emergency

Earth Used To Be Orange

TodayEarth is a pale blue dot, as famously coined by the late Carl Sagan. But 2.5 billion years ago, it would have been a pale orange dot owing to the methane produced by organisms and finding exoplanets that look similar could suggest they, too,have life on their surface.

This is according to a new study by Giada Arney from the University of Washington and her colleagues, presented atthe American Astronomical Societys Division for Planetary Sciences conference inMaryland this week. The research used geological data to examine what Earth would have looked like in the Archaean era, 2.5 billion years ago, and see if this appearance could help in the hunt for habitable exoplanets. Turns out, it might.

During this era, methane molecules in the atmosphere broken downby light formed complex hydrocarbons, organic compounds of hydrogen and carbon, giving Earth an orange haze, or smog, that would have been visible from space. There are two possible sources for such methane biological, namely life, or geological processes, such as on Saturn’s moon Titan. Thus, finding exoplanets with anorange hue could suggest they are going through a similar process to that which occured on theyounger Earth.

As Arney explains, to find out if an exoplanets orange hue comes from biological or geological processes, youll need to find out how much carbon dioxide is there. If its a lot, it could be Earth-like; if not, its probably more like Titan.

If we saw a hydrocarbon haze in an exoplanets atmosphere, it could suggest a methane source consistent with biological methane production, but it isnt enough to just detect the haze, she told IFLScience. To argue that the haze is a sign of life, youd have to also characterize the background atmosphere, particularly the amount of carbon dioxide.

Arney said Archaean Earth’s hue would have been similar to Titan, shown. NASA

On Earth, our haze which would have extended 20 to 70 kilometers (12 to 43 miles)into the atmosphere eventually gave way to the relatively bluer appearance we have today as the amount of oxygen grew. Oxygen destroys methane, so once levels started rising 2.5 billion years ago, the haze disappeared for good. But its a good indicator of biosignatures.

At the moment, we know of a few exoplanets that have hazes or clouds in their atmospheres, but we cant be sure they are Earth-like hydrocarbon hazes just yet. Future telescopes like the James Webb Space Telescope(JWST), though, could potentially characterize them.

Perhaps, in the continuing search for worlds like Earth, we may have to start looking for more of these pale orange dots.

The study will be published in the journal Astrobiology.

Read more: http://www.iflscience.com/space/earth-used-look-orange

Here’s How We Could Find Aliens

Were spending quite a bit of time now looking for signals from aliens, or signs of life on a world outside the Solar System. But we havent really stopped to consider the opposite; what worlds are we visible to, and who might be trying to get in contact?

One team of astronomers has sought to address this problem. Ren Heller, an astronomer at the Max Planck Institute for Solar System Research in Gttingen, Germany, and Ralph Pudritz, an astronomer at McMaster University in Hamilton, Canada, report their findings in the April issue of Astrobiology Magazine.

Their argument is as follows. Our main method of finding planets at the moment is the transit method, where we look for the dip in light from distant stars as a planet passes in front. This relies on a planets orbital plane being visible from Earth; if we are seeing the system face on, the planet is undetectable via this method.

By the same token, any aliens residing on planets in the direction of our North and South poles would be unable to use this method to find us. Thus, in efforts of making first contact through initiatives like the Breakthrough Listen project the researchers say we should look for planets in the direction of our orbital path around the Sun, our transit zone.

There are, of course, other methods of detecting planets. These include the radial velocity method, looking for gravitationalwobbles in a starfrom the presence of a planet, and direct imaging. But Heller says that the ease of a transit method might make it attractive to a race at a similar technological level to us.

The transit method is a relatively cheap one to use, because the stellar transit of a planet yields a lot of information about the planetary atmosphere without the need to actually see the planet, Heller told IFLScience. Using transit spectroscopy, we have already identified traces of certain gases in the atmospheres of exoplanets.

Hence, others might also find it more comfortable and less expensive to find us via our solar transits.

The transit method relies on spotting dips in brightness from an orbiting planet in our line of sight. NASA

The researchers found 82 Sun-like stars that fall in the transit zone within 3,260 light-years from Earth, but they predict hundreds of thousands more could be viable targets. Two-way communication at these distances would be pretty difficult, but if an alien race sprung up a long time ago, perhaps they sent us a message from one of these worlds when they noticed we were a habitable planet with life albeit more primitive on the surface.

For this reason, the researchers argue in their paper that the transit zone is an ideal region to be studied in detail by projects such as Breakthrough, alongside existing projects like the Search for Extraterrestrial Intelligence (SETI), which uses the Allen Telescope Array in California. However, there are no current plans by the Breakthrough project to look in this region.

If any of these planets host intelligent observers, they could have identified Earth as a habitable, or even as a living, world long ago, and we could be receiving their broadcasts today, the researchers write.

Heller noted to IFLScience that direct observations of a planet, using large-large space telescopes,is something that might be possible in 100 years, and another race who has developed this technology would not need to rely on transit zones. But until then, its reasonable to think others might have progressed in a similar way to us, and at some point relied on the transit method.

So as we continue to study other worlds, perhaps it is important to ask: Is anyone studyingus?

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Read more: http://www.iflscience.com/we-should-look-worlds-where-aliens-might-be-looking-us-argue-astronomers