"S-type asteroids are one of the most common objects in the asteroid belt," says Bose.
Bose explains, "This means S-type asteroids and the parent bodies of ordinary chondrites are likely a critical source of water and several other elements for the terrestrial planets."
"This means S-type asteroids and the parent bodies of ordinary chondrites are likely a critical source of water and several other elements for the terrestrial planets," Bose explained."And we can say this only because of in-situ isotopic measurements on returned samples of asteroid regolith - their surface dust and rocks.
Itokawa is an S-type asteroid that is around 1,800 feet long and around 700 - 1,000 feet wide.
Many of the asteroids we've examined close up have been of just one type--the so-called S-type asteroids (S stands for silicaceous).
What we think we know is that the S-type asteroids are the source of the ordinary chondrites, which are the most common stony meteorites that fall on Earth.
are of a stony composition, and Itokawa is often referred to as a "rubble pile" due to the boulders, rocks and dust all stuck together by gravity (and possibly van der Waals forces).
Most asteroid specialists suspect that S-type asteroids
have undergone some kind of "space weathering," a catchall term applied to the various processes that might somehow transform the surfaces of ordinary chondrite asteroids into ones with S-type spectra.
Although its disk was not resolved, Masursky's reflectivity suggests that it may not be an S-type (stony) asteroid, as had been assumed based on its orbital association with the Eunomia family of S-type asteroids
. It was named for renowned planetary geologist Harold Masursky (1923-90).
They found that the inner asteroid belt is dominated by S-type asteroids
. The minor planets 951 Gaspra and 243 Ida, studied by Galileo in 1991 and 1993, respectively, are S types, as is 433 Eros.
Spectroscopically, S-type asteroids
bear some resemblance to the meteorite varieties called ordinary chondrites and stony-irons, both of which contain the silicate minerals pyroxene and olivine as well as iron.
Carlson, who heads the NIMS team, the object consists of roughly the same material as Ida itself, with a moderately reflective rocky composition common to S-type asteroids
. "We know for sure it's not an interloper," says imaging-team leader Michael J.