Exoplanet hunters have been busy. Since 2011 astronomers have discovered, on average, about three exoplanets every week—a precious few of which lie in the “habitable zone,” where water could take liquid form. This chart maps the known cosmic neighborhood of 861 planets. Click on the options under "Select layout" to map the planets based on their location in the sky, or on their distance from the Sun. (Since the Kepler planet-hunting satellite aims at a single spot in the Northern Hemisphere, a huge group of planets can be found near the 18-hour mark.)



Here we've separated the planets into four categories. Gas giants, the easiest to find, are massive planets the size of Jupiter, Saturn and above. Neptunian planets are smaller gaseous objects that still weigh more than 10 Earth masses. Super-Earths weigh between two and 10 Earth masses; these planets could be either rocky or perhaps made of gas. And the Terrestrial planets are those with an Earth-like size.



Despite the apparent multitude of nearby planets, researchers have been able to find just a minuscule fraction of what’s out there. Astronomers estimate that our Milky Way galaxy holds more than 100 billion planets.

Graphics and interactive by Jan Willem Tulp (Sources: the Exoplanet Data Explorer at exoplanets.org; planetquest.jpl.nasa.gov; “The Exoplanet Orbit Database,” by J. T. Wright et al., in Publications of the Astronomical Society of the Pacific, Vol. 123, no. 902; 2011)