Researchers have detected presence of water in grains of dust obtained from the asteroid Itokawa. This finding can be a important clue on how water formed in Earth. The studies have been published in the journal Science Advances.
The peanut shaped asteroid, Itokawa was found in 1998 by LINEAR, a collaboration of NASA with United States Air Force. It has been named after Japanese engineer, Hideo Itokawa. It has a very low density and has a rotation time of 12 hours.
A team of researchers from Arizona State University has measured the quantity of water in the small particles of dust which were carried to earth by the Japanese spacecraft, Hayabusa. Hayabusa, a robotic space probe is manufactured by the Japan Aerospace Exploration Agency for studying the elements, characteristics of Itokawa. It started its journey, collected more than 1500 regolith particles and returned back to Earth in 2010. Though this is not the first evidence of presence of water in an asteroid, scientists have detected water for the first time in laboratory. In other cases, it was done with the help of information collected by telescopes or the equipments present in the spacecrafts.
The first proof of water in asteroid was found in 2010 when scientists used Infrared Telescope Facility of NASA to detect water ice on the asteroid Themis. Also in December, 2018 scientists detected hydrated minerals while studying the rocks of the asteroid Bennu. After these discoveries, scientists have come to the conclusion that presence of water is quite common in our solar system. It may be present either in the form of water ice or hydrated minerals.
From the current findings, the scientists at ASU have concluded that the silaceous asteroids like Itokawa , which are stony asteroids composed of silicates and also one of the most frequently found rocks in space might have delivered almost half of Earth’s water during its formation.
Ziliang Jin, researcher at School of Earth and Space Exploration at ASU along with fellow cosmochemist Maitrayee Bose calculated the abundance of water along with the percentage composition of deuterium and hydrogen, a factor which can indicate the similarity of the water to the water found on Earth. It has been found that the composition of isotopes of hydrogen are similar to Earth.
The team at ASU received five samples out of the 1500 ones brought by spacecraft Hayabusa. Each one measured about half of width of human hair. They have been obtained from the Moses Sea, lying in the middle of the asteroid Itokawa.