GJ 1132 b: An Earth-Sized Exoplanet with a New Atmosphere
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Exoplanet Terraforming and Its Possibilities
Terraforming remains a significant topic of discussion in the field of astronomy, especially as human missions to Mars draw closer. This concept involves the transformation of a planet that is currently uninhabitable into one with a life-supporting atmosphere. The methods to achieve this transformation are still being debated. Entrepreneur Elon Musk has introduced provocative ideas, such as the controversial notion of "Nuking Mars" to initiate terraforming processes.
While it is not uncommon to find exoplanets devoid of atmospheres, evidence supporting the existence of a "secondary atmosphere" on these celestial bodies has been limited. However, new findings from astronomers at the Jet Propulsion Laboratory in Southern California may have uncovered a significant breakthrough. GJ 1132 b, an exoplanet located approximately 41 light-years from Earth, appears to be regenerating its atmosphere after the initial one was stripped away by intense radiation from its host red dwarf star.
Evolution of GJ 1132 b
Researchers speculate that GJ 1132 b began as a "sub-Neptune" but has since transformed into a terrestrial, rocky planet with characteristics somewhat similar to Earth. Formed around 4.5 billion years ago, both planets share similar densities and atmospheric pressures, rich in hydrogen that has gradually cooled over time. Nonetheless, their evolutionary paths have been notably different.
"The detection of an atmosphere on this rocky planet raises the possibility that the numerous powerfully irradiated Super-Earth planets, believed to be the evaporated cores of Sub-Neptunes, may, under favorable circumstances, host detectable atmospheres."
~ Study Authors
Unlike Earth, which has always been a rocky planet, GJ 1132 b initially resembled a gas giant like Neptune. According to the research, the intense radiation from the red dwarf star stripped GJ 1132 b of its hydrogen and helium-rich atmosphere, exposing its rocky core. What makes this case intriguing is what researchers observed using the Hubble Telescope.
Observations of Atmospheric Regeneration
The Hubble Telescope allowed astronomers to detect signs that GJ 1132 b is acquiring a new atmosphere. Typically, exoplanets lacking any atmosphere are viewed as "uninteresting," yet GJ 1132 b has captured researchers' attention for what appears to be a regeneration of its atmosphere.
Based on direct observations and theoretical modeling, the team suggests that the new atmosphere comprises molecular hydrogen, hydrogen cyanide, methane, and an aerosol haze reminiscent of Earth's smog. The study authors propose that the hydrogen lost earlier was absorbed back into the planet’s molten core and is now leaking out, replenishing the atmosphere.
GJ 1132 b completes an orbit around its red dwarf star in just 1.5 days due to its close proximity. Its elliptical orbit may also create "gravitational pumping" effects, potentially leading to extreme tidal forces acting upon the exoplanet. Researchers believe that the planet's crust could be only a few hundred feet thick and that its flat surface might exhibit cracking due to these tidal flexing forces.
Future Research and Questions
This raises a critical question: are these observations merely an unusual occurrence or indicative of a more common phenomenon in the universe? The upcoming launch of the James Webb Space Telescope (JWST), equipped with advanced infrared capabilities, will be pivotal in validating these findings and identifying other exoplanets exhibiting similar characteristics.
The complete research can be accessed on the preprint server arXiv and is expected to feature in a forthcoming edition of the Astronomical Journal. Stay updated with relevant content—consider subscribing to my mailing list.