In the late 20th century the scientific community was pretty sure there were other planets (and another Earth-like planet) around distant stars, but they were still to be discovered. In 1995 the astronomical community rejoiced as the first exoplanet was discovered around another star. We have come a very long way since then.
While we have detected Earth-like planets before, they have always been around red dwarf stars. The decreased glare from these comparatively small stars make the smaller rock planets easier to detect. Astronomers have now found an Earth-like planet that is orbiting a star very similar to our own Sun for the first time.
The exoplanet is called KOI-456.04 (sexy name, I know) and it is less than twice the size of Earth. It’s orbiting the star Kepler-160, which has about 93 percent the brightness of our Sun. This new Earth-like planet even orbits the host star at more or less the same distance as ours does, and it takes 378 days to complete one orbit or the star.
There are many ways we detect exoplanets these days, but the most popular methods are the transit method and the wobble method, also know. as radial velocity. A few exoplanets have been discovered by direct imaging and microlensing.
The MIT team that made the discovery found the planet by combing through old Kepler Space Telescope data using two new algorithms meant to study the star’s brightness. Instead of seeing a sudden dimming of the star’s light (as used with the transit method), the usual sign of a passing planet, the algorithms checked for subtler dimming.
While it is still being confirmed by colleagues and peers, the publishers of the study is confident that it is the first time we’ve found such a planet. It is 3,140 lightyears away, so while you won’t be going there anytime soon it is in our astronomical backyard.