In 2003, the Japan Space Exploration Agency (JAXA) launched the Hayabusa spacecraft, the world’s first mission of sample recovery from an asteroid. The target, a nearby space rock dubbed 25143 Itokawa, was classified as a near-Earth object and a potentially hazardous asteroid.
This intriguing asteroid has fascinated researchers for almost two decades now. Aside from the prospect that it could smash into our planet within the next few million years, as shown by computer simulations of its trajectory, Itokawa has stumped astronomers with “its unusual structure and mysterious lack of craters,” states NASA.
The elongated space rock, measuring some 500 meters (1,640 feet) in diameter, was visited by Hayabusa (or “Peregrine Falcon” in Japanese) 13 years ago and the encounter yielded precious asteroid samples that are still being studied today.
“Beset by many problems, after a seven-year, six-billion-km odyssey Hayabusa returned around 1,500 precious asteroid grains to Earth,” notes the European Space Agency (ESA), which recently unveiled a unique photo of one of these asteroid grains, examined in detail under a microscope.
“Seen on a microscopic support, this sharp-edged grain of rock is an extraterrestrial object — a tiny sample from the Itokawa asteroid, retrieved by Japan’s Hayabusa mission and now being tested by ESA researchers,” the space agency explained in the photo release.
This tiny speck of asteroid dirt, which Space.com noticed “looks like a weird strand of ‘extraterrestrial’ hair,” is now part of a study that aims to understand what happens on the surface of asteroids by examining the static charging properties of the sample.
Despite being incredibly tiny, no wider than a human hair, the asteroid grain displays tiny cracks and “microcraters,” created as a result of exposure to solar wind — the outflow of highly charged particles coming from the sun, the Inquisitr previously reported.
Measuring just 40.95 microns across, the minuscule speck of alien rock has extremely sharp edges since the vacuum of space has kept Itokawa safe from the normal wear and tear that terrestrial rocks experience under the actions of water.
Charged By The Solar Wind
Asteroids hurtling through space lack the protective atmospheres that planets have, which means their surface is directly exposed to the solar wind.
As the charged particles of the solar wind batter the surface of an asteroid, they transfer some of their charge into the material that makes up the outer surface.
The same goes for Itokawa, says ESA scientist Fabrice Cipriani, who is currently studying the asteroid grain to uncover how static electricity influences the interactions between asteroid particles in the outer surface.
According to his findings, the static charging properties of asteroid surface dust can impact the entire structure of the space rock.
“The way the layers are held together, especially if the asteroid body is very small, is affected,” Cipriani explains in the video below.
The researcher and his team are currently conducting an experiment in which grains from the Itokawa asteroid are examined in a test chamber, where the scientists “bombard them with electrons and measure the amount of charges which are accumulating on the surface, and how those charges distribute on the surface,” Cipriani detailed.
Hayabusa And Hayabusa-2
The asteroid grain was retrieved by Hayabusa after its historic touchdown on Itokawa in November 2005, when the spacecraft managed to snag the asteroid dust samples. Five years later, Hayabusa had completed the journey back home, bringing its invaluable cargo along with it.
“Extremely precious, these Hayabusa grains have become the focus of scientific study around the world — and three of them are currently here, at ESA’s ESTEC technical center in the Netherlands,” state ESA officials.
Meanwhile, the mission’s successor, Hayabusa-2, is busy studying another asteroid. After chasing asteroid Ryugu for 3.5 years through space, the Japanese orbiter finally stationed itself in the space rock’s orbit in late June and has recently snapped the first close-up photo of this mysterious asteroid, the Inquisitr reported earlier today.