10/03/2017 – Ephemeris – OSIRIS-REx and the asteroid Bennu

Ephemeris for Tuesday, October 3rd. The Sun will rise at 7:43. It’ll be up for 11 hours and 35 minutes, setting at 7:18. The Moon, 2 days before full, will set at 6:11 tomorrow morning.

Eleven days ago, on September 22nd, a small spacecraft named OSIRIS-REx zipped past the Earth to gain speed and alter the inclination of its solar orbit to reach the asteroid Bennu late next year. Bennu is rated as a potentially hazardous asteroid, with a tiny chance of colliding with the Earth late in the next century.

Discovered in 1999, and named by a 9-year-old boy in a contest run by the Planetary Society after an Egyptian god who is depicted as a heron, because the spacecraft kinda looked like one. It is a carbonaceous asteroid, containing very primitive material from the dawn of the solar system. OSIRIS-REx will take a sample of the asteroid and return it to the Earth in 2023 if all goes well. The Earth pass also allowed it to calibrate its instruments.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Artist’s conception of OSIRIS-REx about to collect a sample from asteroid Bennu. Image Credit:
NASA/Goddard/Chris Meaney

OSIRIS-REx observes the Earth. Here is the Pacific Ocean with Australia at the lower left, and the western US and Baja California at the upper right. Credit: NASA’s Goddard Space Flight Center/University of Arizona

NASA’s caption:  A color composite image of Earth taken on Sept. 22 by the MapCam camera on NASA’s OSIRIS-REx spacecraft. This image was taken just hours after the spacecraft completed its Earth Gravity Assist at a range of approximately 106,000 miles (170,000 kilometers). MapCam is part of the OSIRIS-REx Camera Suite (OCAMS) operated by the University of Arizona. Visible in this image are the Pacific Ocean and several familiar landmasses, including Australia in the lower left, and Baja California and the southwestern United States in the upper right. The dark vertical streaks at the top of the image are caused by short exposure times (less than three milliseconds). Short exposure times are required for imaging an object as bright as Earth, but are not anticipated for an object as dark as the asteroid Bennu, which the camera was designed to image.