NASA Announces 7 Earth-Size Planets Found Around Single Star, with Some in Habitable Zone

[Guest_Jim_*]

Last year three planets were discovered in the TRAPPIST-1 system and today it has been announced that, with the help of the Spitzer Space Telescope, four more planets have been found there, bringing the total to seven. Using Spitzer's data the sizes of these planets have been measured and first estimates of the inner-six's masses have also been made. Based on that information, these planets are most likely rocky planets, like Earth, and also Earth-like in size. While it will take more observations, it is possible all seven of these worlds possess liquid water on their surfaces, though only three of them are actually within the host-star's habitable zone. The seventh planet, which has not yet had its mass estimated, could be an icy, "snowball-like" world.

While these planets may have some similarities to Earth, the TRAPPIST-1 system is very different. The star is considered an ultra-cool dwarf, which means it is cool enough for even the nearest planet to have liquid water on its surface. In fact, all of these planets are closer to this star than Mercury is to the Sun. The orbits are also so close together that if someone were to stand on the surface of one planet, they may be able to make out geological features and even clouds on another. Being so close to the host star, it is possible the planets are tidally locked, meaning one side is always facing the star, just like how one side of the Moon always faces Earth.

For now we can expect at least NASA's Spitzer Space Telescope, Hubble Space Telescope, and the Kepler observatory, specifically designed for planet-hunting, to continue studying TRAPPIST-1, which is named for the Transiting Planets and Planetesimals Small Telescope in Chile that originally found the system. This new information will be used to help plan the missions for the upcoming James Webb Space Telescope, launching next year with the capability to detect the fingerprints of water, methane, oxygen, ozone, and other chemicals in the planets' atmosphere.

 

 

Source: NASA

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