This eight-frame animation is based on the first ever images [
http://www.boulder.
] of a double asteroid [
http://www.boulder.
]! Formerly thought to be a single enormous chunk of rock, asteroid 90 Antiope [
http://cfa-www.harv
NumberedMPs00001.htm l ] resides in the solar system's [
http://space.jpl.na
] main asteroid belt [
http://seds.lpl.ari
asteroids.html ] between Mars and Jupiter. Now, these premier images reveal Antiope to actually consist of two 50 mile wide asteroids separated by about 100 miles. Like weights on each end of an elastic string, the pair mutually orbit [
http://hyperphysics
orbv.html#bo ] their center of mass, or balance point in the space between them, once every 16.5 hours. Binary asteroids and asteroids with moons [
http://antwrp.gsfc.
] are believed to be rare, but observations of their orbits allow a direct determination of asteroid masses and densities. Surprisingly, Antiope and known [
http://www.cfht.haw
] asteroid-moon [
http://antwrp.gsfc.
] systems are found to have densities closer to ice than rock, despite their relatively dark and unreflective surfaces. These sharp images were made at the Keck Observatory atop the Hawaiian volcano Mauna Kea using newly developed adaptive optics [
http://www.mtwilson
AdapOpt/Overview/ ] technology to overcome the blurring effect [
http://antwrp.gsfc.
] of Earth's atmosphere.
Explanation
This eight-frame animation is based on the first ever images [
http://www.boulder.
] of a double asteroid [
http://www.boulder.
]! Formerly thought to be a single enormous chunk of rock, asteroid 90 Antiope [
http://cfa-www.harv
NumberedMPs00001.htm l ] resides in the solar system's [
http://space.jpl.na
] main asteroid belt [
http://seds.lpl.ari
asteroids.html ] between Mars and Jupiter. Now, these premier images reveal Antiope to actually consist of two 50 mile wide asteroids separated by about 100 miles. Like weights on each end of an elastic string, the pair mutually orbit [
http://hyperphysics
orbv.html#bo ] their center of mass, or balance point in the space between them, once every 16.5 hours. Binary asteroids and asteroids with moons [
http://antwrp.gsfc.
] are believed to be rare, but observations of their orbits allow a direct determination of asteroid masses and densities. Surprisingly, Antiope and known [
http://www.cfht.haw
] asteroid-moon [
http://antwrp.gsfc.
] systems are found to have densities closer to ice than rock, despite their relatively dark and unreflective surfaces. These sharp images were made at the Keck Observatory atop the Hawaiian volcano Mauna Kea using newly developed adaptive optics [
http://www.mtwilson
AdapOpt/Overview/ ] technology to overcome the blurring effect [
http://antwrp.gsfc.
] of Earth's atmosphere.
Explanation