NASA/JPL Revealed Discovery of 7 Earth-Sized Planets Existing In A Habitable Zone Around a Single Star

This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system. The double star Alpha Centauri AB also appears in the image. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface. Credits: ESO/M. Kornmesser

NASA streamed a live press conference on its website Wednesday morning to inform the world of its discovery of not one, but seven Earth-sized planets that exist in a habitable zone around a single nearby star.

The planets were observed by NASA’s Spitzer Space Telescope around a tiny, nearby, ultra-cool dwarf star called TRAPPIST-1, according to a NASA press release.

Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.

“This is the most exciting result I have seen in the 14 years of Spitzer operations,” said Sean Carey, manager of NASA’s Spitzer Science Center at Caltech/IPAC in Pasadena, “Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets.”

NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate. Science operations are conducted at the Spitzer Science Center at Caltech.

A paper published in this week’s science journal Nature suggests that the six inner planets are located in the temperate zone, where the temperature at the surfaces of these planets could be between 0 and 100 degrees Celsius.

In May 2016, Michaël Gillon and colleagues reported the detection of three exoplanets transiting an ultracool dwarf star called TRAPPIST-1, which is located 12 parsecs (about 39 light years) from the Sun, according to Nature.

Motivated by this discovery, the authors conducted a monitoring campaign of the star from the ground and from space that allowed them to identify four additional planets in this system. Initial mass estimates suggest that the six inner planets have masses that are similar to the mass of Earth and probably have rocky compositions.

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.

“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”

Following up on the Spitzer discovery, NASA’s Hubble Space Telescope has initiated the screening of four of the planets, including the three inside the habitable zone. These observations aim at assessing the presence of puffy, hydrogen-dominated atmospheres, typical for gaseous worlds like Neptune, around these planets.

Spitzer, Hubble, and Kepler will help astronomers plan for follow-up studies using NASA’s upcoming James Webb Space Telescope, launching in 2018. Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone, and other components of a planet’s atmosphere With much greater sensitivity.

Webb also will analyze planets’ temperatures and surface pressures which are key factors in assessing their habitability, according to NASA.

For more information about Spitzer, visit http://www.nasa.gov/spitzer.

For more information on the TRAPPIST-1 system, visit https://exoplanets.nasa.gov/trappist1.

For more information on exoplanets, visit http://www.nasa.gov/exoplanets.