Eddie Gonzales Jr. – MessageToEagle.com – An international team of astronomers led by Cornell’s Lisa Kaltenegger has characterized the first potentially habitable world – more massive than our own blue planet – outside of our own solar system.
Located about 31 light-years away, the super-Earth planet – named GJ 357 d – was discovered in early 2019 owing to NASA’s Transiting Exoplanet Survey Satellite (TESS), a mission designed to comb the heavens for exoplanets.
“This is exciting, as this is TESS’s first discovery of a nearby super-Earth that could harbor life – TESS is a small, mighty mission with a huge reach,” Kaltenegger, associate professor of astronomy, director of Cornell’s Carl Sagan Institute and a member of the TESS science team, said in a press release.
“With a thick atmosphere, the planet GJ 357 d could maintain liquid water on its surface like Earth, and we could pick out signs of life with telescopes that will soon be online,” she said.
Astronomers from the Institute of Astrophysics of the Canary Islands and the University of La Laguna, both in Spain, showed that the distant solar system – with a diminutive M-type dwarf sun, about one-third the size of our own sun – harbors three planets, with one of those in that system’s habitable zone: GJ 357 d.
Last February, the TESS satellite observed that the dwarf sun GJ 357 dimmed very slightly every 3.9 days, evidence of a transiting planet moving across the star’s face. That planet was GJ 357 b, a so-called “hot Earth” about 22% larger than Earth, according to the NASA Goddard Space Flight Center, which guides TESS.
Follow-up observations from the ground led to the discovery of two more exoplanetary siblings: GJ 357 c and GJ 357 d. Exoplanet GJ 357 c sizzles at 260 degrees Fahrenheit and has at least 3.4 times Earth’s mass. However, the system’s outermost known sibling planet – GJ 357 d, a super-Earth – could provide Earth-like conditions and orbits the dwarf star every 55.7 days at a distance about one-fifth of Earth’s distance from the sun. It is not yet known if this planet transits its sun.
Researchers simulated light fingerprints, climates and remotely detectable spectra for a planet that could range from a rocky composition to a water world.
“We built the first models of what this new world could be like,” Jack Madden said.
“Just knowing that liquid water can exist on the surface of this planet motivates scientists to find ways of detecting signs of life.”
“If GJ 357 d were to show signs of life, it would be at the top of everyone’s travel list – and we could answer a 1,000-year-old question on whether we are alone in the cosmos,” Kaltenegger said.
Written by Eddie Gonzales Jr. – MessageToEagle.com Staff