In the lower left portion of this image, the Earth can be seen, as well as the much smaller Moon to Earth's right. When MESSENGER took this image, a distance of 183 million kilometers (114 million miles) separated the spacecraft and Earth. To provide context for this distance, the average separation between the Earth and the Sun is about 150 million kilometers (93 million miles). Though it is a beautiful, thought-provoking picture, viewing our planet from far away was not the main reason that the mission team planned the collection of this image. Instead, this image was acquired as part of MESSENGER's campaign to search for vulcanoids, small rocky objects that have been postulated to exist in orbits between Mercury and the Sun. Though no vulcanoids have yet been detected, the MESSENGER spacecraft is in a unique position to look for smaller and fainter vulcanoids than has ever before been possible. MESSENGER's vulcanoid searches occur near perihelion passages, when the spacecraft's orbit brings it closest to the Sun. Today is another such perihelion, and MESSENGER is taking a new set of images to search for tiny asteroids lurking close to the Sun.
Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
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