Across the Universe: Myriad planets

This column first ran in The Tablet in September 2012 One hundred thousand planets. That’s the census we can infer for just one corner of the Milky Way Galaxy being watched by the Kepler space telescope, according to results presented [August 2012] at the International Astronomical Union in Beijing. Watching each of 145,000 stars in a bit of the Milky Way about 10 degrees wide over many years (three and a half years, [as of that time]), Kepler is looking for faint dips in brightness occurring on a regular basis that can be attributed to the passage, a “transit”, of a planet in front of that star. So far some 2300 candidate planets have been identified. (Many stars have more than one candidate.) But in order for us to see such a blip, the planet’s orbit must be lined up almost exactly between the star and us; we’re missing any planets whose orbits are tilted above or below their star … Continue reading