Methane ice of unknown origin exists on the surfaces of the icy dwarf planets Eris and Makemake. Analysis of data from the NASA/ESA/CSA James Webb Space Telescope shows that Ellis and Makemake have rocky cores that have undergone significant radiation heating and are still hot/hot enough to produce methane. There is a possibility.
grain other. Researchers have discovered evidence of hydrothermal or metamorphic activity deep within the icy dwarf planets Eris and Makemake. Image courtesy of Southwest Research Institute.
“We're seeing some interesting signs of a hot period in a cool place,” said Dr. Christopher Grein, a planetary researcher at the Southwest Research Institute.
“I approached this project thinking that because the cold surfaces of large Kuiper Belt Objects (KBOs) can store volatile materials like methane, they should have ancient surfaces with material inherited from the proto-solar nebula. I participated.”
“Instead, Webb had a surprise for us! We found evidence of a thermal process producing methane from inside Ellis and Makemake.”
Dr. Grein and his colleagues used the Webb to observe isotope molecules on the surfaces of Ellis and Makemake for the first time.
These so-called isotopologues are molecules containing atoms with different numbers of neutrons. These provide data that helps us understand the evolution of planets.
The astronomers measured the composition of the dwarf planet's surface, specifically the ratio of deuterium (deuterium, D) to hydrogen (H) in methane.
Deuterium is thought to have formed in the Big Bang, and hydrogen is the most abundant atomic nucleus in the universe.
The D/H ratio of planetary bodies provides information about the origin, geological history, and formation routes of hydrogen-containing compounds.
“The moderate D/H ratio observed by Mr. Webb discredits the existence of primordial methane on the ancient Earth's surface. The D/H ratio of primordial methane would be much higher,” Dr. Grein said. I did.
“Instead, the D/H ratio indicates the geochemical origin of the methane produced deep inside. The D/H ratio is like a window. You can use it to look into the subsurface.”
“Our data suggest that temperatures in the cores of these world rocks could increase and methane could be cooked.”
“Nitrogen molecule (N2) may be generated as well, and this has also been confirmed in Eris. ”
“Hot cores may also indicate a potential source of liquid water beneath the surface of the ice.”
“If Eris and Makemake harbored, or perhaps still harbor, warm or hot geochemistry in their rocky cores, then the surface of these planets is probably geologically recent, due to cryogenic volcanic activity. could be supplied with methane,” said Dr. Will Grundy. Astronomer at Lowell Observatory.
“We discovered the carbon isotope ratio (13C/12C) suggests that the surface has been resurfaced relatively recently. ”
“Following NASA's New Horizons flyby of the Pluto system, and with this discovery, the Kuiper Belt turns out to be much more alive than we imagined in terms of hosting a dynamic world.” said Dr. Grein.
“It's not too early to start thinking about sending spacecraft to fly close to other of these objects to put Webb's data into geological context. I'm sure we'll see the surprises that lie ahead. I think you’ll be surprised!”
of study It was published in the magazine Icarus.
_____
Christopher R. Grein other. 2024. Moderate D/H ratios in the Ellis and Makemake methane ices indicate evidence of hydrothermal or metamorphic processes in the interior: a geochemical analysis. Icarus 412: 115999; doi: 10.1016/j.icarus.2024.115999
Source: www.sci.news
