Seeker Archives

Kepler Makes First Exoplanet Discovery After Mission Reboot

NASA's Kepler space telescope has detected its first new extrasolar planet after mission engineers were able to save the mission from a premature death after two of the exoplanet hunter's four stabilizing reaction wheels failed last year.

NASA's Kepler space telescope has detected its first new extrasolar planet after mission engineers were able to save the mission from a premature death after two of the exoplanet hunter's four stabilizing reaction wheels failed last year.

Called "K2″, the extended mission arose from an "innovative idea" that appears to have given the prolific telescope a new lease on life.

NEWS: Kepler Returns! Exoplanet Mission Makes New Discoveries

"Last summer, the possibility of a scientifically productive mission for Kepler after its reaction wheel failure in its extended mission was not part of the conversation," said Paul Hertz, NASA's astrophysics division director at the agency's headquarters in Washington D.C. "Today, thanks to an innovative idea and lots of hard work by the NASA and Ball Aerospace team, Kepler may well deliver the first candidates for follow-up study by the James Webb Space Telescope to characterize the atmospheres of distant worlds and search for signatures of life."

During its primary mission, Kepler was kept steady by four functioning reaction wheels, allowing extremely precise observations of one small area of the sky along the Cygnus Arm of the Milky Way. The field of view kept an unblinking eye on tens of thousands of target stars. Throughout the campaign, Kepler detected the slight dimming of starlight caused by hundreds of exoplanets passing in front of their host stars - events known as transits.

After many transits, Kepler was able to identify and characterize some of the most profound exoplanetary discoveries of our time.

NEWS: Exoplanet-Hunting Kepler Telescope Gets New Mission

Unfortunately, in May 2013, a second reaction wheel failed inside the instrument, destabilizing it. Kepler was therefore unable to stay trained on that specific area of sky. But that didn't stop mission engineers from thinking up a new mission profile that would allow Kepler to widen its search.

Instead of staying fixed on one part of the sky, earlier this year, Kepler was tasked with repeatedly studying different areas of the Milky way along the plane of the solar system as it orbited, with Earth, around the sun. To maintain stability during its new campaign, mission engineers turned to the sun for help, using the continuous pressure of photons from sunlight to act as a counterbalance.

By February 2014, K2 had gathered its first test results and Andrew Vanderburg, a graduate student at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., spotted an exoplanetary candidate in the publicly available test data.

The coordinates of the candidate was then sent to ground observatories and a discovery was consequently confirmed - the revitalized Kepler mission was back in the exoplanet-hunting business!

ANALYSIS: How Kepler Could Die and Keep Giving

K2′s first exoplanet has been designated HIP 116454b, an alien world that is approximately 2.5 times the diameter of Earth with a fast, 9-day compact orbit around its host star. HIP 116454b is 180 light-years away in the constellation Pisces.

"The Kepler mission showed us that planets larger in size than Earth and smaller than Neptune are common in the galaxy, yet they are absent in our solar system," said Steve Howell, Kepler/K2 project scientist at NASA's Ames Research Center in Moffett Field, Calif. "K2 is uniquely positioned to dramatically refine our understanding of these alien worlds and further define the boundary between rocky worlds like Earth and ice giants like Neptune."

Having embarked on its third campaign, K2 has already studied dense star clusters, star forming regions and observed several celestial objects in our own solar system. It seems that having only half of its reaction wheels functioning hasn't held the mission back and scientists are excited as to what Kepler will discover next, in turn, helping future missions, like the JWST, to seek out hints of habitability in these distant alien worlds' atmospheres.

Source: NASA

Exquisite Exoplanetary Art

Sept. 19, 2011 --

They're alien worlds orbiting distant stars far out of reach of detailed imaging by even our most advanced telescopes. And yet, day after day, we see vivid imaginings of these extrasolar planets with the help of the most talented space artists. The definition of an extrasolar planet -- or "exoplanet" -- is simply a planetary body orbiting a star beyond our solar system, and nearly 700 of these extrasolar worlds have been discovered so far (plus hundreds more "candidate" worlds). With the help of NASA's Kepler space telescope, the ESO's High Accuracy Radial velocity Planet Searcher (HARPS), French COROT space telescope and various other advanced exoplanet-hunting observatories, we are getting very good at detecting these worlds, but to glean some of the detail, we depend on artist's interpretations of fuzzy astronomical images and spectral analyses. That's the way it will be until we build a vast telescope that can directly image an exoplanet's atmosphere or physically travel to an alien star system. So, with the flurry of recent exoplanet discoveries, Discovery News has collected a few of the dazzling pieces of art born from one of the most profound searches mankind has ever carried out: the search for alien worlds orbiting other stars; a journey that may ultimately turn up a true "Earth-like" world.

The Transit

As an exoplanet passes in front of its star as viewed from Earth, a very slight dip in starlight brightness is detected. Observatories such as NASA's Kepler space telescope use this "transit method" to great effect, constantly detecting new worlds.

Hot Jupiters

Some exoplanets orbit close to their parent stars. Due to their close proximity and generally large size, worlds known as "hot Jupiters" are easier to spot than their smaller, more distant-orbiting cousins.

Habitable Worlds

The primary thrust of exoplanet hunting is to find small, rocky worlds that orbit within their stars' "habitable zones." The habitable zone, also known as the "Goldilocks zone," is the region surrounding a star that is neither too hot nor too cold. At this sweet spot, liquid water may exist on the exoplanet's surface. Where there's water, there's the potential for life.

A Phantom

Usually, exoplanet hunters look for the slight dimming of a star or a star's "wobble" to detect the presence of an exoplanet. However, in the case of Kepler-19c, its presence has been detected by analyzing its gravitational pull on another exoplanet, Kepler-19b. Kepler-19c is therefore the Phantom Menace of the exoplanet world.

Keeping Warm

The habitable zone seems to be the pinnacle of extraterrestrial living. If you're an alien with similar needs to life on Earth, then you'll need liquid water. If your planet exists outside your star's habitable zone, well, you're in trouble. Either your world will be frozen like a block of ice, or boiling like a kettle. But say if your world had the ability to extend your star's habitable zone? There may be some atmospheric factors that might keep water in a comfy liquid state. Even better, if you like deserts, a dry world could even be oddly beneficial.

Crazy Aurorae

Planets with a global magnetic field, like Earth, have some dazzling interactions with the winds emanating from their stars. The high-energy particles bombard the planet's atmosphere after being channeled by the magnetism. A wonderful auroral lightshow ensues. But say if there's an exoplanet, with a magnetosphere, orbiting really close to its star? Well, stand back! The entire world would become engulfed in a dancing show, 100-1000 times brighter than anything we see on Earth.

The "Candidates"

"Candidate" exoplanets are often mentioned, especially when talking about detections by the Kepler space telescope. But what does this mean? As a world passes in front of its star, slightly dimming the starlight, this isn't considered a "confirmed" exoplanet detection. To make sure that signal is real, more orbital passes of the exoplanet need to be logged before a bona fide discovery can be announced. Until then, these preliminary detections are called exoplanet candidates.

Angry Suns, Naked Planets

Exoplanets come in all sizes and all states of chaos. Some might have wonky orbits, others might be getting naked. Other times, they're simply being ripped apart by X-rays blasted from their parent star. Bummer.


Super-Earths get a lot of press. Mainly because "Earth" is mentioned. Sadly, most of these worlds are likely completely different to anything we'd call "Earth." And you can forget calling the vast majority of them "Earth-like." It's simply a size thing -- they're bigger than Earth, yet a lot smaller than Jupiter, hence their name, "super-Earth." Easy.

Let's Go!

For now, we have to make do with artist's renditions of exoplanets for us to visualize how they may look in their alien star systems. However, plans are afoot to send an unmanned probe to an interstellar destination. Although these plans may be several decades off, seeing close-up photographs of these truly alien worlds will be well worth the wait.