Also, the exoplanet exists a mere 1.4 miles (2.3 kilometers) from its sun-like star, 55 Cancri A.
“This atmosphere is probably supported by outgassing from the rocky interior of 55 Cancri e, and we think this is the first measurement of a secondary atmosphere on a rocky exoplanet.
Two possible scenarios exist to explain the atmosphere of 55 Cancri e. First, the super-Earth could be a lava world atop which a thin, vaporized silicate atmosphere exists.
If it’s rock, it’s molten lava, which helps the outgassing process that supports a secondary atmosphere because of a molten surface.”
He explained that gas dissolves in 55 Cancri’s global lava ocean, constantly “bubbling out” to form the secondary atmosphere.
However, the composition of the secondary atmosphere that replaced the first remains uncertain.
But if the rock is more like Earth’s mantle, water, carbon monoxide and carbon dioxide would dominate the secondary atmosphere.”
Hu pointed out that, on both counts, 55 Cancri e seems to be “optimized” for replacing a lost primary atmosphere with a secondary atmosphere.
Scientists have found that a blazing hot lava planet thought to be made of diamond developed a second atmosphere using the James Webb Space Telescope (JWST), but only after its star destroyed the planet’s first atmosphere.
Known as 55 Cancri e, the planet is roughly 41 light-years away from Earth and has a mass approximately nine times that of Earth and a width nearly twice that of Earth. This planet is categorized as a “super-Earth” among the many extrasolar planets, or “exoplanets,” that scientists have compiled over the years. In other words, it is far lighter than planets like Uranus and Neptune but much more massive than Earth. However, for 55 Cancri e, that is the extent of the resemblance to our world.
Due to its extreme density, astronomers have surmised that the majority of this exoplanet is made of compressed carbon, or diamond. Furthermore, the exoplanet is only 1.4 miles (2.03 kilometers) away from 55 Cancri A, its sun-like star. In terms of distance between Earth and the sun, that is equivalent to 0.01544. Its close proximity to its host star causes 55 Cancri e to orbit it once every 17 Earth hours, resulting in a surface temperature that is scorching hot at 4,400 degrees Fahrenheit (\2,400 degrees Celsius).
As is the case with other rocky planets that orbit their stars at such close distances, 55 Cancri has thus lost its original or primary atmosphere due to radiation from its star. Though the scientists behind the discovery believe they understand how this happened, the new research suggests a thick layer of gases surrounds the planet, suggesting it has “grown” a second atmosphere.
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The planet has a significant atmosphere, according to the measurement of the thermal emissions from this rocky planet, according to Renyu Hu, a researcher at the California Institute of Technology (Caltech) and member of the team behind this discovery, who spoke with Space . com. Our estimation is that this is the first measurement of a secondary atmosphere on a rocky exoplanet, and it is most likely supported by outgassing from 55 Cancri e’s interior. It is really thrilling. “.
How the star defied 55 Cancri e.
Because of the “wobble” it produced in the motion of its host star as observed from Earth, 55 Cancri e was discovered in 2004. For exoplanet discovery, this is known as the radial velocity exoplanet discovery method. When the planet was first discovered orbiting a far-off main sequence star—a star whose core is still converting hydrogen to helium—it was known by the name Janssen.
Scientists discovered more about the planet’s 0.7 Earth-day orbit and carbon makeup as they conducted additional research on it. In 2016, the Hubble space telescope conducted the first atmospheric study of an exoplanet and discovered that 55 Cancrie had hydrogen and helium in its atmosphere.
There are two explanations for the atmosphere of 55 Cancri e.
Firstly, the super-Earth might be a lava world with a thin silicate atmosphere on top that has evaporated. It would consist of the volatiles and chemical elements that are easily lost from the planet as a result of radiation from its star, such as carbon, nitrogen, hydrogen, and sulfur. Or, on the other hand, volcanism over time may have produced a dense secondary atmosphere on the planet.
Using JWST observations of the planet during its so-called secondary eclipse—when it passed behind the star 55 Cancri A—Hu and colleagues looked into which of these scenarios was true. Information from two subsequent eclipses of 55 Cancri e excluded the possibility that it is a nearly barren lava world with no significant atmosphere.
The team believes that the molten nature of the planet is what allowed 55 Cancri e to grow its secondary atmosphere, and there is no denying that the planet is a lava-covered hellscape.
55 Cancri e receives a lot of heat in the form of radiation from its close proximity to the host star. Earth’s temperature is maintained at a very high level by that heat, according to Hu. All matter on Earth is liquefied at these temperatures. If it’s rock, it’s molten lava, which facilitates the process of outgassing that makes a secondary atmosphere possible due to a molten surface. ****.
He explained that the global lava ocean of 55 Cancri dissolves gas, which then continuously “bubbles out” to form the secondary atmosphere.
According to the research, hydrogen and helium would have made up the majority of 55 Cancrie’s initial atmosphere, which it would have had since forming around its star. The contents of the secondary atmosphere that took the place of the first, however, are still unknown.
“What makes up the rock beneath it determines the makeup of the secondary atmosphere,” Hu explained. One can also create a hydrogen-helium atmosphere similar to the primary atmosphere if the rock is very reducing (i.e., composed of compounds that gain electrons and hydrogen). However, water, carbon monoxide, and carbon dioxide would predominate in the secondary atmosphere if the rock resembled the Earth’s mantle. “.
Hu continued, stating that models used to explain the measurements favor a significant amount of carbon dioxide and carbon monoxide, even though the JWST observations of 55 Cancri e do not definitively state what the planet’s atmosphere is composed of.
Is it possible for 55 Cancri e to really produce a secondary atmosphere?
Though Hu notes that it is one of the hottest of its kind, 55 Cancri e is by no means the only rocky planet observed orbiting so near to its host star. The group isn’t sure if this suggests that the other intensely hot terrestrial worlds could have also developed secondary atmospheres.
This can be attributed to the fact that 55 Cancri e is rather unique.
With a mass of 1.08 times that of Earth, the chunk of rock serves as a protective shield for the volatiles from star radiation, according to Hu. It’s anticipated that a tiny, rocky planet in a close orbit around its star may lose all of its volatile material and eventually lose its atmosphere. “.”.
This implies that whether a planet will keep its atmosphere and “grow” another, it depends not only on how far away it is from its star but also on how big that world is. Hu noted that 55 Cancri e appears to be “optimized” for substitute primary atmosphere replacement on both counts.
Hu said that the JWST’s observing power and infrared sensitivity, which make it perfect for characterizing exoplanet atmospheres, would not have allowed for the analysis of 55 Cancri e in this manner.
