Earth from Deep Space

On May 6, 2010, the MESSENGER spacecraft now in orbit around Mercury, transmitted photos of the Earth and Moon from
183 million kilometers (114 million miles) away.

The average distance between the Earth and the Sun is about 150 million kilometers (93 million miles). The photographs were taken at a distance more than 30 million miles farther away than the Sun.

The 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.

The orientation of the image (shown full size below) has north near the bottom of the image. Earth is seen near the boundary of the constellations Libra and Scorpius. Specifically, the right ascension and declination coordinates for Earth in this image are 15:37:04 and -20:45:42, respectively. The bright star directly to the right of the Earth-Moon pair and almost to the edge of the image is the star delta Scorpii, a bright star near the "head" of that constellation. The pair of stars in the lower-right corner are the stars omega-1 and omega-2 Scorpii.
Click here to download a detailed star map with Earth's position plotted.
Earth and Moon from MESSENGER
Earth and Moon from 114 Million Miles

Some of the bright features in this image, such as the streaks located near the upper right, are not stars but rather are due to cosmic ray particles striking the MESSENGER camera while the image was being taken.

Images used to search for vulcanoids involve 10-second exposure times, which is a relatively long time in comparison to imaging planetary surfaces, like Mercury's. The longer exposure time makes it more likely that such a cosmic ray strike will occur. Consequently, when searching for vulcanoids, four 10-second images are taken back to back; by comparing the images, bright features that appear in only one can be identified as being due to a cosmic ray strike.


NASA Lunar Science Institutre