Five years after its discovery, one of Milky Way’s most exciting exoplanets got even more interesting. GJ 1132 b, once one of the most important planets outside the Solar System, seems to have lost its sense of purpose – and has since evolved into a new one.
This is probably the first time we have identified an exoplanet that has radically reshaped the atmosphere with volcanic activity.
Not only has this allowed scientists to study the magmatic composition of an exoplanet by studying the atmosphere, it raises the possibility that many more exoplanets of this type could harboring an atmosphere we could study. A paper outlining the findings was approved The Astronomical Journal, with an introduction available on arXiv.
“It’s very interesting because we believe that the atmosphere we see now has been regenerated, so it could be a secondary atmosphere,” said astronaut Raissa Estrela of the Jet Propulsion Laboratory. Laboratory (JPL) at NASA in Pasadena, California.
“At first we thought these high-altitude planets could be very depressing because we believed they had lost their atmosphere. But we looked at the preconceived notions of the this planet by Hubble and we said, ‘Oh no, there’s a feeling.’ “
GJ 1132 b built a puzzle for scientists. His discovery was announced in 2015 to a long-awaited stay. It’s a rocky world, 1.66 times bigger and 1.16 times the size of Earth – and it’s just 41 light-years away. Astronomers thought that a study could help us gain a better understanding of the rocky planets in our own Solar System (like Earth, Venus, and Mars).
There are important differences, however. GJ 1132 b is on a 1.6-day orbit around its host star, GJ 1132. Although GJ 1132, a small red dwarf, is much colder and lower than the Sun, its temperature would still be very hot – around 530 Kelvin (257 ° C, 494 ° F). It would also lose GJ 1132 b with 19 times as many stellar radiation events as the Earth receives from the Sun.
Moreover, GJ 1132 b is thought to have originated as a type of exoplanet quite different from Earth, Mars and Venus. Astronomers believe that the exoplanet originated as a mini-Neptune – smaller than Neptune but larger than Earth – and that is what remains of the rocky heart after the original hydrogen atmosphere was evaporated by stellar radiation during the 5 billion year life of the exoplanet, leaving just a few hundred million years.
Astronauts used the MPG / ESO telescope in Chile to look at the exoplanet as it passed between us and its star. These transitions cause relatively low doses of starlight – but, if an exoplanet has an atmosphere, some waves of light can be captured or emitted by the atoms in the atmosphere, which ‘appears to contain a number of elements.
According to MPG / ESO data, the GJ 1132 b actually had an atmosphere – and it appeared to be high in hydrogen, which was consistent with the mini-Neptune situation.
Now, a closer look at the exoplanet with the Hubble Space Telescope has turned that idea upside down.
GJ 1132 will not harbor a simple hydrogen sensor, Hubble data revealed. Instead, it is a complex mixture of hydrogen, hydrogen cyanide, methane, and ammonia, with a thick hydrocarbon mist similar to Earth ‘s smog.
According to the team’s data, the atmospheric pressure at the surface is similar to the Earth’s atmospheric pressure. Given that this feeling is still leaking into space, that is surprising.
To find out what ‘s going on, the team turned to computer modeling. The most likely explanation seems to be that the original hydrogen atmosphere of GJ 1132 was introduced into the ocean of molten magma that covered the exoplanet when it was still very young.
Although the surface of the exoplanet is cooled by this, the interior is still warm and active as the interaction of gravity with the star keeps it hot and soft. Volcanic activity releases that hydrogen, among other elements, to create a new feeling. As the felt drains, it is replenished with hydrogen still stored in a GJ 1132 b suit.
This discovery may explain why there are so many micro-Neptunes out there. It could also mean the beginning of life as a Neptune mini as one way to create a world like Earth, Venus, and Mars – rocky, volcanic (at least at one point) active, and air harbor.
“How many terrestrial planets don’t start as boundaries? Some can start as sub-Neptunes, and they become terrestrial areas through a device that takes pictures of the private atmosphere. This process works early in the life of a planet , when the star is warmer, “said astronaut Mark Swain of JPL, lead author of the study.
“Then the star cools down and the planet just sits there. So you have this equipment where you can cook the feeling in the first 100 million years, and then things will settle. And if you can refresh the atmosphere, you probably can. “
It is also very interesting in itself. The atmospheric combination of GJ 1132 b, even with the limited observations we received, reflects the geological processes within exoplanet 41 light-years away. That’s wild – but it also suggests that we may be able to learn even more with the launch of next-gen instruments like the James Webb Space Telescope.
“This second feeling comes from the surface and interior of the planet, so it’s a window on the geology of another world,” said astronaut Paul Rimmer of Cambridge University in the UK.
“A lot more work needs to be done to look through it, but finding this window is very important.”
The research will be published in The Astronomical Journal, and is available on arXiv.