OSIRIS-REx Captures Unique View Of Earth, Moon And Pleiades

Earth and moon look like two planets in conjunction in the constellation Cetus seen from NASA’s OSIRIS-REx asteroid mission on Jan. 17. Click HERE for a higher-resolution view. NASA

I do enjoy a big picture perspective. You too? As part of an engineering test, NASA’s OSIRIS-REx spacecraft captured this image of the Earth and Moon using its navigation camera on January 17 from a distance of 39.5 million miles (63.6 million km). When the camera snapped the image, the spacecraft was moving away from Earth at 19,000 miles per hour (8.5 km/sec).

Earth and the fainter, smaller moon dominate the photo. From the spacecraft’s perspective they’re in the head of the constellation Cetus the Whale. At upper is the familiar Seven Sisters star cluster also known as the Pleiades (PLEE-uh-deez), while Aries the Ram, the smallest zodiac constellation, occupies the upper right.

Here’s a map of the same section of sky you can see this week in the southwestern sky around 7 o’clock local time. Sorry, no Earth and moon here. You’re standing on them. Stellarium

Whenever we see two planets next to each other in conjunction, the event takes place against the backdrop of the familiar constellations. While we’ve seen photos of Earth and the moon taken from spacecraft before, this image is one of the few (only?) that so clearly shows them against a recognizable backdrop. It pointedly reminds us that we live on a small ball of rock orbited by a smaller ball of rock both ensconced in the vastness of space.

Since the view is clearly a wide-angle one and resembles almost one-for-one what the stars look like with the naked eye, the image conveys a good “naked eye” view of the scene as if the viewer were on board the spacecraft.

Meanwhile, OSIRIS-REx continues on its mission to rendezvous with the carbon-rich asteroid Bennu this August. After studying it from orbit, the spacecraft will spiral down to the surface, grab a 2.1-ounce sample of dust and pebbles and return it to Earth in a canister that will land in the Utah desert in September 2023.