PASADENA, Calif. — A NASA spacecraft that discovered and characterized tens of thousands of asteroids throughout the solar system before being placed in hibernation will return to service for three more years starting in September, assisting the agency in its effort to identify the population of potentially hazardous near-Earth objects, as well as those suitable for asteroid exploration missions.

The Wide-field Infrared Survey Explorer (WISE) will be revived next month with the goal of discovering and characterizing near-Earth objects (NEOs), space rocks that can be found orbiting within 28 million miles (45 million kilometers) from Earth’s path around the sun. NASA anticipates WISE will use its 16-inch (40-centimeter) telescope and infrared cameras to discover about 150 previously unknown NEOs and characterize the size, albedo and thermal properties of about 2,000 others — including some which could be candidates for the agency’s recently announced asteroid initiative.

“The WISE mission achieved its mission’s goals and as NEOWISE extended the science even further in its survey of asteroids. NASA is now extending that record of success, which will enhance our ability to find potentially hazardous asteroids, and support the new asteroid initiative,” said John Grunsfeld, NASA’s associate administrator for science in Washington. “Reactivating WISE is an excellent example of how we are leveraging existing capabilities across the agency to achieve our goal.”

via NASA Spacecraft Reactivated to Hunt for Asteroids | NASA.

PASADENA, Calif. — The larger of the two moons of Mars, Phobos, passes directly in front of the other, Deimos, in a new series of sky-watching images from NASA’s Mars rover Curiosity.

A video clip assembled from the images is at http://youtu.be/DaVSCmuOJwI .

Large craters on Phobos are clearly visible in these images from the surface of Mars. No previous images from missions on the surface caught one moon eclipsing the other.

The telephoto-lens camera of Curiosity’s two-camera Mast Camera (Mastcam) instrument recorded the images on Aug. 1.  Some of the full-resolution frames were not downlinked until more than a week later, in the data-transmission queue behind higher-priority images being used for planning the rover’s drives.

These observations of Phobos and Deimos help researchers make knowledge of the moons’ orbits even more precise.

“The ultimate goal is to improve orbit knowledge enough that we can improve the measurement of the tides Phobos raises on the Martian solid surface, giving knowledge of the Martian interior,” said Mark Lemmon of Texas A&M University, College Station.  He is a co-investigator for use of Curiosity’s Mastcam.  “We may also get data good enough to detect density variations within Phobos and to determine if Deimos’ orbit is systematically changing.”

The orbit of Phobos is very slowly getting closer to Mars. The orbit of Deimos may be slowly getting farther from the planet.

Lemmon and colleagues determined that the two moons would be visible crossing paths at a time shortly after Curiosity would be awake for transmitting data to NASA’s Mars Reconnaissance Orbiter for relay to Earth. That made the moon observations feasible with minimal impact on the rover’s energy budget.

Although Phobos has a diameter less than one percent the diameter of Earth’s moon, Phobos also orbits much closer to Mars than our moon’s distance from Earth. As seen from the surface of Mars, Phobos looks about half as wide as what Earth’s moon looks like to viewers on Earth.

via NASA Rover Gets Movie as a Mars Moon Passes Another | NASA.