The James Webb Telescope reveals details of Pluto’s moon – 10/02/2024 – Science

Observations by the James Webb Telescope provide scientists with a more complete understanding of the formation and evolution of Charon, a moon of Pluto and the largest orbit of any of the dwarf planets in our solar system.

For the first time, Webb detected carbon dioxide and hydrogen peroxide — both frozen as solids — on the surface of Charon, a spherical body about 1,200 kilometers in diameter, according to He studies Released this Tuesday (1). These elements are in addition to water ice and compounds containing ammonia and organic materials that have previously been documented on the moon’s natural surface.

Charon was discovered in 1978, and is the largest moon in the solar system relative to the size of the planet it orbits. With a diameter of about half the diameter and one-eighth the mass of Pluto, it is a dwarf planet located in a cold region of the outer solar system called the Kuiper Belt, beyond the distant planet Neptune.

The distance between Charon and Pluto is about 19,640 kilometers, compared to the average of 384,400 kilometers that separates the Earth from the Moon.

Most of Charon’s surface is grey, with red areas around its poles made up of organic matter.

Webb’s observations are based on data obtained when NASA’s New Horizons spacecraft flew over Charon while visiting the Pluto system in 2015. The new study took advantage of the capabilities of a telescope that launched in 2021 and began collecting data next year to make observations across the range. Wider wavelengths than previously available.

The presence of hydrogen peroxide indicates irradiation processes that Charonte has undergone over time, according to the researchers. Furthermore, carbon dioxide is suspected to be an indigenous component dating back to the formation of the Moon about 4.5 billion years ago.

Hydrogen peroxide was formed, according to the researchers, when water ice on the surface of the satellite changed chemically due to the constant bombardment of ultraviolet rays coming from the Sun, as well as energetic particles from the solar wind and galactic cosmic rays passing through the Earth. universe.

The carbon dioxide recorded by the telescope was likely buried beneath the surface but ended up exposed due to impacts on the moon, the researchers said. It must have been part of the primordial matter from which Charon and Pluto were originally formed.

Scientists were surprised that carbon dioxide had not been detected before.

“The discovery of carbon dioxide was a satisfactory confirmation of our expectations,” said Sylvia Protobaba, associate director of the Division of Space Studies at the Southwest Research Institute in Boulder, Colorado, a co-investigator on the New Horizons mission and lead author of the report. A study published in a journal nature Communications.

“The discovery of hydrogen peroxide on Charon’s surface was unexpected. Frankly, I did not expect to find evidence of its presence on the surface,” Protobaba added.

The new observations help tell a broader story about the celestial bodies that populate our solar system.

“Every small object in the outer solar system is a unique piece of a larger puzzle that scientists are trying to put together,” Protobaba said.

The researchers used a web tool to conduct four observations in 2022 and 2023, to get complete coverage of Charon’s northern hemisphere.

“Webb’s new observations add carbon dioxide and hydrogen peroxide to the known inventory of Charon’s surface components. Both provide insight into the ongoing processes of irradiation and resurfacing due to the impact,” said study co-author Ian Wong, a space telescope science scientist. Institute in Baltimore.