Tuesday, 21 November 2023 – 10:01 WIB
Jakarta – Scientists from the United States Aeronautics and Space Administration or NASA are confused by several planets that appear to be shrinking. They suspect the cause could be radiation.
Reporting from SciencalertTuesday, November 21 2023, there are many planets outside the solar system, such as foreign planets that are very far away, called exoplanets, their shape can be filled with Jupiter gas, or even rocky balls the size of planet Earth.
However, recently it was discovered that there is a mysterious gap where there should be planets that are 1.5 to twice the width of Earth.
Mysterious Gap
Among the more than 5,000 exoplanets that NASA has discovered, there are many super-Earths (which are 1.6 times larger than Earth) and many sub-Neptunes (about two to four times the diameter of Earth), but almost no planets in between.
“Exoplanet scientists have enough data to say that this gap is not a coincidence. There is something going on that is preventing planets from reaching and/or staying at this size,” said Jessie Christiansen, a research scientist at Caltech and science lead for NASA Exoplanets Archive.
Scientists suspect this is happening because some sub-Neptunes are shrinking – losing their atmospheres and accelerating through the size gap until they become as small as a super-Earth.
Reporting from the same source, the latest research conducted by Christiansen shows that these planets are shrinking because radiation from the planet’s core is pushing its atmosphere away.
This research, published in The Astronomical Journal, may be able to solve the mystery of lost exoplanets.
The Planets Themselves Are Pushing Their Atmospheres Away
A shrinking planet may not have the mass (and therefore the gravity) to maintain its atmosphere. However, the exact mechanism for atmospheric loss remains unclear.
The new study supports one hypothesis that scientists call “core-powered mass loss,” according to the article.
Core-powered mass loss is not a trendy new workout plan. This occurs when a planet’s core emits radiation that pushes against its atmosphere from below, causing the atmosphere to separate from the planet over time.
Another hypothesis, called evaporation, says that a planet’s atmosphere is dissipated by radiation from its host star.
However, evaporation is expected to occur by the time the planet is 100 million years old – and loss of core-powered mass could occur closer to the planet’s billionth birthday, according to the release.
To test these two hypotheses, Christiansen’s team looked at data from NASA’s now-defunct Kepler Space Telescope.
They examined star clusters that are more than 100 million years old. Because the planets are thought to be the same age as their host stars, the planets in this cluster are old enough to experience evaporation, but not old enough to experience core-powered mass loss.
Scientists discovered that most of the planets there still have atmospheres, so the possibility of mass loss caused by core energy is greater.
“However, recent research suggests an ongoing mass loss sequence in which both processes operate,” Christiansen wrote on X, the platform formerly known as Twitter, sharing a link to Harvard’s assessment posted online in July
According to Christiansen’s statement in the release, the research isn’t finished either – especially as our understanding of exoplanets will evolve over time.
2023-11-21 03:01:01
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