Looking for New Earth
New extrasolar planets no longer make the news. The number of known exoplanets currently stands at 218 and climbing, and the International Astronomical Union has deemed it utterly impractical to give them names. However, most of the known exoplanets are inhospitably large and gaseous – like Jupiter, but bigger. This is simply because bigger planets are easier to find. Although we have actual pictures of some planets (where “pictures” means the entire planet is shown in about the same number of pixels as Mario’s head on the original NES, but you take what you can get) the smaller ones have all been detected indirectly, by examining the minute wobbles a planet produces in its star’s position or gravitational field.
In today’s issue of Nature, scientists at NASA’s Jet Propulsion Laboratory report on a lab prototype telescope capable of visually resolving Earth-like planets at a distance of 30 light-years. It’s an immense technical feat, but a number of engineering challenges (and yeah, political challenges too) remain before the device can be put into orbit with the Terrestrial Planet Finder project.