Kepler living up to its promise
The Kepler mission was launched March 6th, 2009 from Cape Canaveral. It’s about 2.7m diameter and 4.7m long, and weighed about a tonne at launch. Its 1.4m mirror is coupled to a sensitive photometer and it will be spending three and a half years staring at the same spot in the sky.
Sound kinda boring? Well, staring at one place means that it can very accurately measure the brightness of starts in its field of view. Some of these stars will dim, brighten, and ‘blink’ over time. Above the earth’s atmosphere, this can’t be caused by the air around us – it’s not the same kind of twinkling (“scintillation”) we see from the back garden.
What some of these ‘blinks’ actually indicate is a distant planet in orbit around the star. When it passes in front of the star, a tiny part of the starlight is hidden. When the planet completes its transit, the brightness increases again. Watching very carefully over long periods of time, this information can be used to work out how many planets are in orbit, how big they are, and how closely they orbit their parent star.
Kepler was specifically designed to analyse stars to understand the characteristic makeup of other solar systems, and in particular to search for Earth-like planets which may be host to alien life.
Watch this space. There will be many more.