Planet bonanza: NASA announces discovery of 715 new worlds

The NASA’s Kepler mission announced the discovery of 715 new planets. These newly-verified planets orbit 305 stars, revealed multiple-planet systems much like our own solar system.  This discovery marks a significant increase in the number of known small-sized planets more akin to Earth than previously identified exoplanets, which are planets outside our solar system. 
About the discovery of 715 new planets

  • Technique used by scientists: Verification by multiplicity that relies in part on the logic of probability.
  • Used the planet-hunting Kepler telescope. It observed 150,000 stars and has found a few thousand of those to have planet candidates.
  • Nearly 95% of these planets are smaller than Neptune that is almost four times the size of Earth.
  • Four of the new planets are less than 2.5 times the radius of Earth, and they orbit their host suns in the “habitable zone” – the region around a star where water can keep a liquid state. In other words, it is defined as the range of distance from a star where the surface temperature of an orbiting planet may be suitable for life-giving liquid water.
  • One of these new habitable zone planets known as Kepler-296f – orbits a star half the size and 5% as bright as our sun. Kepler-296f is twice the size of Earth, but scientists do not know whether the planet is a gaseous world, with a thick hydrogen-helium envelope, or it is a water world surrounded by a deep ocean.
  • This latest discovery brings the confirmed count of planets outside our solar system to nearly 1700.

Key terms:

  • Exoplanet (or extrasolar planet): A planet outside the Solar System.
  • Habitable zone:  The region around a star where water can keep a liquid state 

Kepler space telescope mission

  • Launched in 2009, with the sole purpose of finding new stars and planets. In other words, the Kepler space telescope sought to find Earth-like worlds orbiting distant stars in the Constellation Lyra.
  • Orbits around the Sun, 40 million miles from Earth.
  • Named after 17th Century astronomer Mr. Johannes Kepler. 

Outcome of the discovery: The study indicates that the planets in these multi-systems are small and their orbits are flat and circular, resembles pancakes, not our classical view of an atom.