ESOcast 137 Light: Temperate Planet Orbiting Quiet Red Dwarf (4K UHD)
- Author: Marlene Weaver Nov 16, 2017,
Nov 16, 2017, 2:06
Astronomers spotted the planet using the European Southern Observatory's High Accuracy Radial velocity Planet Searcher (HARPS) in Chile.
Ross 128b is 2.6 times more distant from Earth than Proxima b, the potentially habitable planet found in the nearest solar system to the sun.
Where should we look for alien life? There's always some play in these numbers - since we haven't found a guaranteed-habitable planet yet, we can't say for certain if the habitable zone is properly calibrated. "Restricting the target list to quiet stars would disqualify Proxima Cen b and leave Ross 128 b as the best temperate planet known to date".
"Proxima Centauri is particularly active, with frequent, powerful flares that may sterilize (if not stripped out) its atmosphere", lead author Xavier Bonfils of Institut de Planétologie et d'Astrophysique de Grenoble told Futurism via email. That makes this planetary system much more conducive to hosting any potential life. The HARPS instrument, which is mounted aboard a 3.6-meter optical and near-infrared telescope, does not directly observe exoplanets, but instead watches for a minute wobble in the motion of a host star created by the gravitational influence of an orbiting world. "Only HARPS has demonstrated such a precision, and it remains the best planet hunter of its kind, 15 years after it began operations". Notably, this planet has a mass that is similar to Earth's. It is estimated that Ross 128 b's surface temperature is close to Earth's, because the luminosity of the star and the planet's distance from it suggest the Earth-like world doesn't get hit with much more energy than our own planet does. But it is close enough to Ross 128 that it absorbs warmth sufficient for liquid water, one of the requisite ingredients for life, to potentially exist on the surface. Close inspection reveals that Ross 128 has a unusual multiple appearance as this image was created from photographs taken over a more than forty year period by the Digitized Sky Survey 2, and the star, which is only 11 light-years from Earth, moved across the sky significantly during this time. If the planet is too close to the star, its water would evaporate; too far away and the water would freeze into ice. "Depending on its composition and the reflectivity of its clouds, the exoplanet may be life friendly with liquid water as the Earth, or sterile like Venus".
"Ross 128b is very close, which will allow us to see it with a telescope such as E-ELT (European Extremely Large Telescope) in construction for 2025", Bonfils said. Earlier this year, Ross 128 made headlines because it appeared to be sending out a semi-repeating radio signal. I know just where we can start. Sure, it seems to have a lot of good stats, but scientists still don't know what the planet's climate is like, and that could seriously impact its habitability.