The AKARI infrared satellite has detected the existence of water in a number of asteroids for the first time, bringing scientists a step closer to discovering the origin of water on Earth.
A Japanese research team has used the AKARI satellite and discovered that water in the form of hydrated minerals exists in several asteroids. The discovery will contribute to scientific understand of how water is distributed in the solar system, and the origin of water on Earth.
The origins of water on Earth
The Earth is an aqua-planet, and the only planet in our solar system where the presence of water on the surface has been confirmed. However, it is unclear how water on Earth originated. Recent studies have shown that other celestial bodies have, or used to have, a form of water.
Asteroids are one of the candidates that brought water to the Earth. While liquid water is not flowing on the surface, water is retained in them as hydrated minerals, which were produced by chemical reactions of water and anhydrous rocks (aqueous alteration).
At the early stage of the solar system formation, a number of small bodies including asteroids were larger than they are now, and collisions must have been more frequent. For this reason, it is expected that at least some water was brought to Earth by such collisions.
The spectra of the observed asteroids show common patterns. The size and distance of the asteroid is important in making differences of the spectra. To fully understand the patterns they have observed, further observations of more asteroids and a comparison of the measurement of meteorites collected on Earth are required.
Dr. Usui comments: “By solving this puzzle, we can make a significant step towards identifying the source of Earth’s water and unveiling the secret of how life began on Earth”.