Category Archives: Exoplanets

Exoplanets, General, SpaceCasts

Space on the John Batchelor Show: Bob Zimmerman & Hotel Mars, May 21-23, 2013

Bob Zimmerman reports on the latest space news during regular weekly slots (usually Tuesday and Thursdays) on the John Batchelor radio program. See the iTunes free Podcast for links to the latest shows.

Tuesday 05/21/13 Batchelor Hour 4 : Science and politics:

  1.  Climate scientists are forced to revise their climate models because of lack of warming for 15 years.
  2. Democratic senator blames Republicans for Oklahoma tornado, caused by global warming.

Thursday: Space:

  1. Mice and gerbils die on Russian 30 day biology spaceflight.
  2. The impact of a 100 pound meteorite on the Moon produced the brightest flash on record.
  3. Opportunity now has the American record for the longest travel on another planet.
  4. Great Britain gets its first official astronaut.
  5. Scaled Composites blows up a SpaceShipTwo engine on purpose during testing.

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William  (Bill) Borucki, Principle Investigator for the Kepler Space Telescope, talked with Batchelor and David Livingston during the latest Mars Hotel segment. They discussed the status of Kepler after the loss of its reaction wheel and about the Transiting Exoplanet Survey Satellite (TESS) and the Terrestrial Planet Finder (TPF):  John Batchelor Show Hotel Mars, Wednesday, 5-22-13 – Thespaceshow’s Blog.

Exoplanets, Space Systems

Kepler space telescope loses reaction wheel – exoplanet searching crippled

With the loss of another reaction wheel, he Kepler space telescope has lost the ability to maintain the stable orientation needed for observing stars to detect transits of exoplanets: Kepler Mission Manager Update – NASA.

The managers of the project, however, insist that the mission is not finished and they will still be able to do some interesting science with the spacecraft. There is also a lot of data left to analyze.

Nevertheless, for small planets with orbit periods like the earth or Mars, the longer the observation time the better. A earth sized planet only decreases the star’s light by about 0.01% when it transits across the face of the planet. So the more transits, the better. At least three transits are needed for confirmation of an exoplanet. Kepler began observations in 2009 so there would have been 3-4 transits at an earth size orbit but only 1-2 for a Mars orbit.

There was a NASA briefing this afternoon on the situation and some notes were posted at

Examples:

Alan Boyle : “[Principle Investigator William Borucki] bristles at suggestion that @NASAKepler‘s planet-hunting mission is over. “Reasonable possibility” of resuming data collection.”

Jeff Foust: “Bill Borucki: well on our way to determining “eta Earth”, fraction of stars with Earth-sized planets in hab zones. (key goal of mission)”

Jeff Foust: “Borucki: we’ll declare the mission over when there’s no possibility of getting critically important science.”

Astronomy, Exoplanets, Space participation

Planet Hunter citizen scientists confirmed exoplanet in star’s habitable zone

Earlier this year participants in the Planet Hunters citizen science project

confirmed with 99.9 percent confidence the discovery of a Jupiter-sized planet called PH2b orbiting within the “habitable zone” of its star, the range where earth-like planets could have liquid water and possibly sustain life. The researchers also announced 42 new planet candidates, including 20 located in the habitable zone of their respective stars.

– Planet Hunters Project Confirms a New Planet in the “Habitable Zone” – Yale Scientific Magazine.

Participants in the project examine data from the Kepler space observatory, which monitors the light from over 100,000 stars simultaneously to look for dimming when a planet passes in front of the star as seen from earth.

With_sun_spotPlanets transiting across the face of a star will dim its light output.

While the Kepler group have software to find such dimming from the planet transits across the face of stars, there are significant advantages of humans examining the light data directly

Citizen scientists working on Planet Hunters, on the other hand, can consider transits on a case-by-case basis, and can visually detect planets which produce fewer dips in the light-curve; these are the planets with a wider orbit and a longer orbital period that Kepler algorithms often overlook. Nine of the recent planet candidates have orbital periods over 400 days, and most have periods longer than 100 days.

“I didn’t expect that volunteers would be able to find a significant number of planets that the Kepler computers couldn’t. Everything found by volunteers causes Kepler to improve their algorithms,” Professor Fischer added.

Examples of a Kepler data for a planetary transit:

SPH10102031 SPH10102031b