Japanese Probe Finds Water On The Surface Of An Asteroid

For the first time, scientists were able to measure the water content of samples from the surface of an asteroid.

Back in 2003, Japan’s Aerospace Exploration Agency (JAXA) developed and launched a robotic spacecraft, Hayabusa, to explore a small near-Earth Asteroid named 24143 Itokawa.

Thanks to the Japanese probe, scientists were able to study details of the asteroid at the time. These include its composition, shape, density, color, spin as well as its history.

In June 2010, Hayabusa left Itokawa. But before leaving, the robotic probe retrieved 1,500 particles from a part of the asteroid known as the Muses Sea and brought the samples back to Earth for further analysis.

Now, scientists have published a study in the Journal Science Advances, detailing the analysis of five of the asteroid samples. The results are interesting.

Finding Water on An Asteroid

According to CNN, the researchers had no intention of testing the sample for evidence of water. However, two researchers from Arizona State, Jin and Maitrayee Bose, proposed it and the team agreed.

As you may have guessed, they discovered the presence of water in the asteroid samples.

Two of the five samples contain pyroxene – a mineral material that is known to hold water. Upon further analysis, the researcher noted something astonishing. Although Itokawa is dry, samples collected from the asteroid were rich in water.

In a statement to CNN, lead study author and a postdoctoral scholar in Arizona State University’s School of Earth and Space Exploration, Ziliang Jin said:

“We found the samples we examined were enriched in water compared to the average for inner solar system objects.”

Itokawa: A Dry Asteroid With Water

The peanut-shaped Itokawa was once a part of a larger body which was once 12 miles wide. With time, the vast body became exposed to several conditions that induced rough changes.

Between a high temperature of about 1,000 to 1,500 Fahrenheit and the multiple impacts, the asteroid eventually shattered. Then about 8 million years ago, two of the fragments, known as lobes, merged.

The researchers believe that the samples collected by the space probe were 328 feet deep in the larger parent body before it broke into pieces. After the asteroid shattered, the samples were presumably exposed to radiation as well as impacts by micrometeorites.

This could explain why it retained water and why some of the minerals are similar to compositions found on Earth. The scientists theorized that Earth’s early impact with such an asteroid may be responsible for about half of our ocean water.

In a statement to CNN, Bose said:

“This means S-type asteroids and the parent bodies of [non-modified asteroids] are likely a critical source of water and several other elements for the terrestrial planets,” Bose said. “That makes these asteroids high-priority targets for exploration.”