Having lost its original atmosphere, this strange planet is now growing a new one – tech2.org

Having lost its original atmosphere, this strange planet is now growing a new one


Artist's rendering of the exoplanet GJ 1132 b,

Artist’s rendering of the exoplanet GJ 1132 b,
Picture: NASA / ESA / R. Injured (IPAC / Caltech)

Who says you can’t lose your atmosphere with a nearby red dwarf? and then grow a new one with the help of volcanic activity? Tits resilient planet, located 41 light-Earth years, seems to be thriving again after a tough encounter with their host star.

The exoplanet GJ 1132 b is similar to and very different from Earth. Sure, it’s several times wider than our planet, but both worlds share similar densities and atmospheric pressures, and both appeared approximately 4.5 billion years ago. And like our planet, it started out hot with a hydrogen-rich atmosphere, and then gradually cooled down.

However, the backstories of these two planets are distinctively different.

While Earth has always been a rocky, terrestrial world, GJ 1132 b began life as a Neptune-like planet. But as new research shows, a nearby red dwarf erased its original hydrogen- and helium-rich atmosphere with powerful radiation, so GJ 1132 b, having been stripped of its rocky core, is now technically a terrestrial planet. The new article will appear in an upcoming issue of the Astronomical Journal, but a prepress it is available in arXiv.

The authors of the article reached these conclusions based on direct observations of the exoplanet and theoretical models. The telescope chosen was the hubble space telescope, which allowed the team to detect the “secondary atmosphere,” which consists of molecular hydrogen, hydrogen cyanide, methane, and an aerosol haze that resembles smog on Earth.

“It’s very exciting because we think the atmosphere we see now has regenerated, so it could be a secondary atmosphere,” said Raissa Estrela, study co-author and planetary scientist at NASA’s Jet Propulsion Laboratory. in Southern California, explained in a statement. “We first thought that these highly irradiated planets might be pretty boring because we thought they had lost their atmospheres. But we looked at the existing observations of this planet with Hubble and said, ‘Oh no, there’s an atmosphere there.’

In terms of an explanation, the authors say that much of the planet’s current hydrogen was retained earlier, after being absorbed by the blanket of molten magma. Volcanic processes are now causing this stored hydrogen to leak from below, replenishing the new atmosphere, according to the research.

“This process works early in a planet’s life, when the star is at its hottest,” said JPL scientist Mark Swain. lead author of the study, in the NASA statement. “Then the star cools and the planet just stays there. So you have this mechanism where you can cook the atmosphere in the first 100 million years, and then things settle down. And if you can regenerate the atmosphere, maybe you can conserve it. “

GJ 1132 b, which takes just 1.5 days to make a full orbit of its starving host star, is likely prone to tidal warming, in which gravitational forces churn the planet from within. The exoplanet, despite its short year, is in an elliptical orbit, resulting in an effect known as “gravitational pumping.” As GJ 1132 b rocks back and forth, it alternates between crushing and stretching actions, producing a motor that propels the tidal forces. Y, in turn, the preservation of a liquid mantle.

The surface of this exoplanet is probably not very thick, maybe only a few hundred feet deep, according to the authors. The terrain is likely to be fairly flat, with cracks caused by the pumping actions of the tides, from which hydrogen is constantly escaping.

The new study has implications for studying similar worlds located elsewhere in the galaxy.

“Detection of an atmosphere on this rocky planet raises the possibility that the many powerfully irradiated Super-Earth planets, believed to be the evaporated cores of Sub-Neptune, may, under favorable circumstances, harbor detectable atmospheres.” the authors write in the study.

The big question now is, how often does this happen? Is this simply a abnormal occurrence? That could be answered by the upcoming James Webb Space Telescope, which, with its infrared capabilities, should be able to detect planets like this with ease. Furthermore, JWST could also be used to study GJ 1132 by providing new data to affirm these results.

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