Tag Archives: Kepler space telescope

NASA’s Kepler Space Telescope discovers 104 new planets outside of Milky Way

Using data from NASA’s Kepler Space Telescope during the K2 mission in combination with observations from various Earth-based telescopes, an international team of astronomers has discovered 104 new exoplanets, four of which could hold the potential for life.

An illustration of NASA's Kepler Space Telescope during the K2 mission. Credit: NASA/JPL-Caltech

An illustration of NASA’s Kepler Space Telescope during the K2 mission. Credit: NASA/JPL-Caltech

Prior to the K2 mission, the Kepler focused specifically on measuring the frequency with which planets with sizes and temperatures similar to the Earth occurred around sun-like stars. Now, it focuses on cooler and smaller red dwarf-type stars, which are much more common in the Milky way than sun-like stars.

The new mission also focuses on both the northern and southern hemispheres, as opposed to the initial mission, which was limited to examining a specific portion of the sky in the northern hemisphere.

“Kepler’s original mission observed a small patch of sky as it was designed to conduct a demographic survey of the different types of planets,” said Ian Crossfield of the University of Arizona’s Lunar and Planetary Laboratory and leader of the research. “This approach effectively meant that relatively few of the brightest, closest red dwarfs were included in Kepler’s survey. The K2 mission allows us to increase the number of small, red stars by a factor of 20 for further study.”

Of the 104 new exoplanets discovered outside of our solar system, four are of particular interest due to their potential similarities to Earth. The set of planets are between 20 to 50 percent larger than Earth and orbit a star less than half the size of the sun. In addition, two of them are believed to experience radiation levels from their star that are comparable to those experienced by the Earth.

Although the orbits of the new set of planets are fairly tight, Crossfield believes that the current data suggests that we must consider the possibility of life on such planets until further research says otherwise

“Because these smaller stars are so common in the Milky Way, it could be that life occurs much more frequently on planets orbiting cool, red stars rather than planets around stars like our sun,” he said.

The findings were published in The Astrophysical Journal Supplement Series.

Kepler-11 is a sun-like star around which six planets orbit. At times, two or more planets pass in front of the star at once, as shown in this artist's conception of a simultaneous transit of three planets observed by NASA's Kepler spacecraft on Aug. 26, 2010. Image credit: NASA/Tim Pyle

Kepler crossed the 1,000 discovered alien planets milestone

Since it was first launched in 2009, the $600 Kepler mission has discovered more than 1,000 alien worlds. Arguably it’s one of the most successful space mission in history so far, further cementing its status as a legend. The milestone was breached after eight newly confirmed exoplanets were added to the tally, two of which are very similar to Earth and thus could support alien life.

The exoplanet hunter

Table Top model of the Kepler Telescope: A Mission in search of Habitable Planets around other stars. NASA Ames photographer Tom Trower

Table Top model of the Kepler Telescope: A Mission in search of Habitable Planets around other stars. NASA Ames photographer Tom Trower

The Kepler telescope was deployed to probe our Milky Way galaxy for alien planets, in order to see how frequent planets are. It wasn’t long until the first candidates came pouring in, and as of now there are 1,004 confirmed alien planets. Unfortunately, two of the four gyroscope-like reaction wheels that keep Kepler pointed in the right direction have broken down and can’t be fixed. But even if the telescope won’t be collecting any more planet-hunting data, there’s still lots of information to sift through. Scientists have  3,200 additional planet candidates marked by Kepler that they need to probe, 90% of which should end up being confirmed according to the statistical data available so far. Indeed, this should keep them busy for years and years ahead, long enough until the next generation exoplanet hunting telescope will come online: the James Webb Space Telescope.

“Each result from the planet-hunting Kepler mission’s treasure trove of data takes us another step closer to answering the question of whether we are alone in the Universe,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate at the agency’s headquarters in Washington. “The Kepler team and its science community continue to produce impressive results with the data from this venerable explorer.”

NASA Kepler's Hall of Fame: Of the more than 1,000 verified planets found by NASA's Kepler Space Telescope, eight are less than twice Earth-size and in their stars' habitable zone. All eight orbit stars cooler and smaller than our sun. The search continues for Earth-size habitable zone worlds around sun-like stars. Image: NASA

NASA Kepler’s Hall of Fame: Of the more than 1,000 verified planets found by NASA’s Kepler Space Telescope, eight are less than twice Earth-size and in their stars’ habitable zone. All eight orbit stars cooler and smaller than our sun. The search continues for Earth-size habitable zone worlds around sun-like stars. Image: NASA

Two of the newly validated planets, Kepler-438b and Kepler-442b, are less than 1.5 times the diameter of Earth. Kepler-438b, 475 light-years away, is 12 percent bigger than Earth and orbits its star once every 35.2 days. Kepler-442b, 1,100 light-years away, is 33 percent bigger than Earth and orbits its star once every 112 days. Both planets orbit smaller and cooler suns than our own

“With each new discovery of these small, possibly rocky worlds, our confidence strengthens in the determination of the true frequency of planets like Earth,” said co-author Doug Caldwell, SETI Institute Kepler scientist at NASA’s Ames Research Center at Moffett Field, California. “The day is on the horizon when we’ll know how common temperate, rocky planets like Earth are.”

Right now, following observations made between May 2009 to April 2013, the candidate count stands at a whooping 4,175.  Eight of these new candidates are between one to two times the size of Earth, and orbit in their sun’s habitable zone. This includes a planet that’s most similar to Earth in terms of size and mass, a Neptune-sized planet with water vapour in its atmosphere.

Kepler-11 is a sun-like star around which six planets orbit. At times, two or more planets pass in front of the star at once, as shown in this artist's conception of a simultaneous transit of three planets observed by NASA's Kepler spacecraft on Aug. 26, 2010. Image credit: NASA/Tim Pyle

Kepler-11 is a sun-like star around which six planets orbit. At times, two or more planets pass in front of the star at once, as shown in this artist’s conception of a simultaneous transit of three planets observed by NASA’s Kepler spacecraft on Aug. 26, 2010. Image credit: NASA/Tim Pyle

To discover alien planets, Kepler used the transient method in which blips in a star’s brightness are analyzed for telltale signs of an alien planet passover. When an exoplanet orbits its host star and reaches a point in line with the observer (kepler) and the host star, it blocks the incoming light in specific way. Judging from how long the brightness dip lasts, what wavelengths of light become absorbed and so on, scientists can infer size, mass and even atmospheric composition of planets even thousands of light years away. Obviously, bigger planets like those the size of Jupiter are easier to find; they’re the most numerous discovered thus far. Earth-like planets are harder to come by. Earth-like planets that orbit Sun-like stars are even rarer.

Illustration of a exoplanet transiting its parent star in the observational plane. (C) scienceoffice.org

Most Earth-like exoplanet in terms of size and mass discovered

Illustration of a exoplanet transiting its parent star in the observational plane. (C) scienceoffice.org

Illustration of a exoplanet transiting its parent star in the observational plane. (C) scienceoffice.org

Although the Kepler Space Telescope itself is defunct due to a malfunction that rendered it out of operation some months ago, the mission goes on as scientists churn through massive amounts of data gathered by Kepler, enough to keep them busy for years to come. One of the fruits of Kepler is an exoplanet called  Kepler 78b located just 400 light-years away, which apparently is the most Earth-like planet in terms of size and mass discovered thus far. The similarities end here, however. The planet completes a full orbit around its parent star every 8.5 hours compared to Earth’s steady 365-day orbit. This makes Mercury sound like the North Pole in comparison.

Kepler discovers worlds beyond our solar system by studying light. Each time a planet transits between the observational plane Kepler/parent star, a distinct wobble can be measured. Because Kepler 78b has such a short orbital period, scientists were able to gather a whole lot more data than usual, basically collecting enough data to characterize the planet in a few weeks compared to years with other exoplanets.

Each week Kepler 78b circles its star about 20 times, and based on this MIT researchers found the exoplanet is about 1.2 times Earth’s size — making Kepler 78b one of the smallest exoplanets ever measured. The mass was a lot trickier to determine, though. Each planet exerts a gravitational tug on its parent star, and this stellar motion can be detected as a very slight wobble, known as a Doppler shift. Analyzing this effects was daunting to say the least, since the star’s signal was very faint and besides  starspots –   dark patches on the surface of stars – also interfered with measurements.

By tracking the frequency at which certain starspots appeared and devising a set of clever calculations, the MIT researchers found the star completes a full rotation every 12.5 days and d that the star rotates relatively slowly, at 1.5 meters per second — about the speed of a jog, or a brisk walk.

“The star is moving at the same speed as when we walk to school or go grocery shopping,” notes  Roberto Sanchis-Ojeda, an MIT student who was part of the research. “The difference is that this star is 400 light-years away, so imagine how complicated it is to measure such speeds from so far away.”

The most Earth-like exoplanet in terms of size and mass

Knowing the star’s true Dopler Shift, the researchers determined Kepler 78b is  1.7 times more massive than Earth. When considering size as well, this implies that the exoplanet is similar in density to Earth and that it may be primarily made out of iron and rock. So, in many ways, Kepler 78 is pretty similar to Earth, but when considering how close its is to its star, all other similarities end here.

“It’s Earth-like in the sense that it’s about the same size and mass, but of course it’s extremely unlike the Earth in that it’s at least 2,000 degrees hotter,” says team member Josh Winn, an associate professor of physics at MIT and a member of the Kavli Institute for Astrophysics and Space Research. “It’s a step along the way of studying truly Earth-like planets.”

The researchers say they still have a lot to learn about the planet, like its surface and atmospheric composition. Just earlier this month is was reported that a team of NASA scientists made the first cloud map of an exoplanet, Kepler 7b.

Artie Hatzes, a professor of astronomy at the Institute of Thuringer Landessterwarte in Germany, says this is the first Earth-like planet, in terms of mass, size, and composition, that has been fully characterized.

“This is a tricky measurement to make because the star is very active and it has starspots,” says Hatzes, who did not participate in the research. “These create a false Doppler signal often referred to as ‘activity jitter.’ You can use special tricks to disentangle the Doppler wobble due to the planet, and the Doppler velocity variation caused by the spots on the star. If the planet had a much longer orbital period, it would be much more difficult to do so.”

The exoplanet Kepler 78b was characterized in a paper recently published in the journal Nature.

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Kepler telescope malfunction might end search for alien planets

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Dire news came today. Astronomers, and people dreaming of life beyond our solar system alike all over the world, are morning the loss of the Kepler – the space telescope tasked with discovering exoplanets capable of supporting life. One of the telescope’s wheels failed and as such, the telescope can’t stabilize its gaze on a particular position. For now, it’s been put in standby, but realistically speaking the chances of restoring the telescope are very dim.

The $600 million Kepler mission was launched in 2009, and since then it has confirmed  132 planets and spotted more than 2,700 potential ones. Of these confirmed planets, several have been identified as being the so-called “Goldilocks zone”, meaning they’re located on an orbit around their parent stars where conditions necessary for harboring life are possible – primarily the right temperature for sustaining liquid water. The likeliest Earth-like planet found by Kepler is actually a planetary pair, which was discovered just last month.

Bottom line, Kepler has fundamentally altered our view of the Universe and how alien planets form in the Milky Way. Before Kepler there were so many blank spots that one could speculate just about anything. We’ve  now garnered a much deeper and solid understanding of how planets form and just how common they are beyond our solar system – indeed, it turns out most stars have planets orbiting around them, and quite a few of them can be classed as Earth-like.

“Tears are coming to my eyes on and off,” said UC Berkeley astrophysicist Geoff Marcy, a co-investigator on the Kepler mission. “I really think this telescope was a gift to our civilization.”

Since Kepler orbits the sun, mechanically repairing it on-site is out of the question.  Engineers on the ground are trying to restart one of Kepler’s faulty wheels or find a workaround, and if this doesn’t work the telescope could be used for other purposes if it can no longer track down planets. To be fair, the telescope’s 3.5-year-long mission officially ended in 2012, but NASA agreed to keep it running through 2016 at a cost of about $20m a year.

This issue wasn’t entirely unexpected, said John Grunsfeld, associate administrator of NASA’s science mission directorate.

“We have some history with these wheels by this manufacturer, that they have a limited lifetime,” Grunsfeld said.

“Kepler’s not in a place where I can go up and rescue it,” the former astronaut said. Still, he added, “I wouldn’t call Kepler down and out just yet.”

ZME folks, let’s all hope for the best. Kepler, you’ve been wonderful!