The Japan Aerospace Exploration Agency (JAXA) has confirmed that the tiny particles inside the Hayabusa spacecraft‘s sample return container are in fact from the asteroid Itokawa.
Scientists examined the particles to determine if the probe successfully captured and brought back anything from the asteroid, and in a press release said “about 1,500 grains were identified as rocky particles, and most were determined to be of extraterrestrial origin, and definitely from Asteroid Itokawa.”
These are the first samples from an asteroid ever returned to Earth by a space mission. Studying the samples will help astrobiologists understand the compositon of asteroids and their potential role in delivering materials to the Earth that were essential for the origin of life.
Previously, JAXA said that although particles were inside the container, it wasn’t clear if they were from the asteroid or if they could be of terrestrial origin (dust from Earth that could have been inside the container).
Most of the particles are extremely small, about 10 microns in size and require special handling and equipment. Unfortunately they aren’t the “peanut-sized” chunks of rock that the mission originally hoped to capture. This will make analyzing the particles difficult, but not impossible.
During the seven-year round trip journey, Hayabusa arrived at Itokawa in November, 2005. The mechanism that was intended to capture the samples apparently failed, but scientists were hopeful that at least some dust had made its way into the return canister. After a circuitous and troubled-filled return trip home, the sample return capsule was ejected and landed in Australia in June of this year.
Here are the other successful sample return missions: