Water is common across our planet and it’s crucial to life but it is always a rare commodity elsewhere in the inner Solar System. The discovery of ice in the craters of the Moon or buried in deposits on Mars is extremely intriguing. Researchers have looked further now, at the asteroid belt, and investigated if objects that should not have any water might instead be hiding some. And in two cases, they have found it right on the surface.
Researchers from various institutions across the States have employed the data from the retired Stratospheric Observatory for Infrared Astronomy (SOFIA) to look at four dry silicate asteroids. They formed close to the Sun so should be quite devoid of water. The objects in question are Iris, Parthenope, Melpomene, and Massalia, all in the main Asteroid Belt.
“We detected a feature that is unambiguously attributed to molecular water on the asteroids Iris and Massalia,” lead author Dr Anicia Arredondo, from the Southwest Research Institute, said in a statement. “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.”
Previous observations of asteroids couldn’t distinguish between actual water and a close chemical relative: hydroxyl. That’s just oxygen bound to a hydrogen atom. The new work dispels this confusion and estimates that there is about a soda cans worth of water for each cubic meter of asteroid soil, similar to the value based on the observations of the Moon from SOFIA.
“Based on the band strength of the spectral features, the abundance of water on the asteroid is consistent with that of the sunlit Moon,” added Dr Arredondo. “Similarly, on asteroids, water can also be bound to minerals as well as adsorbed to silicate and trapped or dissolved in silicate impact glass.”
SOFIA was a joint project of NASA and the German Space Agency at DLR and it has been instrumental in observing the universe, near and far, in infrared. The specific interest in asteroids is about the past of our Solar System. Understanding these objects can tell how planets evolved.
“Asteroids are leftovers from the planetary formation process, so their compositions vary depending on where they formed in the solar nebula,” explained Dr Arredondo. “Of particular interest is the distribution of water on asteroids, because that can shed light on how water was delivered to Earth.”
A paper describing the discovery is published in The Planetary Science Journal.
Source Link: Water Found On The Surface Of Two Asteroids For First Time Ever