One of the exciting adventures of astronomy is to find other planets like the earth orbiting other stars. The first such planet was found in 1992. On March 6, 2009, NASA launched a planet-hunting satellite called Kepler. Its job was to stare at a spot in the sky containing 150,00 stars, in the Constellation Cygnus, looking for dips in starlight as an orbing planet passed between us and its sun. Kepler collected this data in two missions.
Until its fuel ran out last October, Kepler confirmed 2,800 planets. Nearly 3,000 more candidates remain to be confirmed by follow up observations. Ten years after its launch, one of those candidate planets has been confirmed. The planet is a Jupiter sized planet orbiting a star known as Kepler 1658, about 2,600 light years away.
This giant planet orbits its star in just in 3.8 days. Much work remains to confirm the remaining Kepler candidates.
Based on Kepler's findings astronomers estimate the Milky Way have as many as a trillion or more planets. The exciting question is how many may be Earth-like.