NEW YORK: Scientists have discovered, for the first time, water molecules on the surface of an asteroid.
The team at the Southwest Research Institute (SwRI) in the US observed four silicate-rich asteroids using the FORCAST instrument at the retired Stratospheric Observatory for Infrared Astronomy (SOFIA) to isolate mid-infrared spectral signatures indicative of molecular water in two of them. they. . SOFIA is a joint project of NASA and the German Space Agency.
“Asteroids are remnants of the planetary formation process, so their composition varies depending on where they formed in the solar nebula,” said lead author Anicia Arredondo of SwRI.
“Of particular interest is the distribution of water on asteroids, because it may shed light on how water arrived on Earth,” Arredondo added. Anhydrous or dry silicate asteroids form close to the Sun, while icy materials coalesce further away.
Understanding the distribution of water in our solar system will provide information about the distribution of water in other solar systems and, since water is necessary for all life on Earth, will indicate where to look for potential life, both in our solar system and beyond. .
“We detected a feature that is unequivocally attributed to molecular water on the asteroids Iris and Massalia,” Arredondo said. “We based our research on the success of the team that found molecular water on the sunlit surface of the Moon. We thought we could use SOFIA to find this spectral signature on other bodies.” The findings are detailed in an article in The Planetary Science Journal.
SOFIA detected water molecules in one of the largest craters in the moon’s southern hemisphere.
Previous observations of both the Moon and asteroids had detected some form of hydrogen, but could not distinguish between water and its close chemical relative, hydroxyl. Scientists detected roughly the equivalent of a 12-ounce bottle of water trapped in a cubic meter of soil spread across the lunar surface, chemically bound to minerals.
“Based on the band intensity of the spectral features, the abundance of water on the asteroid is consistent with that of the sunlit moon,” Arredondo said. “Similarly, on asteroids, water may also be bound to minerals, adsorbed on silicate, and trapped or dissolved in silicate impact glass.”
While SOFIA’s FORCAST instrument is apparently not sensitive enough to detect the spectral feature of water if it is present, the team is enlisting NASA’s James Webb Space Telescope, the premier infrared space telescope, to use its precise optics and its superior signal-to-noise ratio to investigate more targets.