Lying near the asteroid rich abyss between Mars and Jupiter high above our Solar System, a unique family of space rocks called Euphrosyne asteroids just got discovered by the scientists at NASA's Jet Propulsion Laboratory (JPL).
The Euphrosynes are distributed at the outer edge of the asteroid belt. These distant asteroids have been dark and distant so far. Their orbital path is unusual, just well above the elliptic, and were named after an asteroid named Euphrosyne. This particular asteroid is 260 kilometers (156 miles) across and is one of the 10 largest asteroids in the main belt. Current-day Euphrosyne is thought to be a remnant of one of the last great collisions that took place 700 million years ago.
WISE obtained the images used to create this view over a period of about a day around May 17, 2010, during which it observed the asteroid four times.
In a new study, the scientists at NASA's JPL, used the agency's orbiting Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) telescope to look at these asteroids to learn more about Near Earth Objects, or NEOs, and what threat they pose to our planet.
Occasionally, NEOs can have close approaches to Earth. Therefore, for the safety of our own planet, we need to study these objects.
After the study, the JPL researchers found that gravitational interactions with Saturn, Euphrosyne asteroids can evolve into NEOs over timescales of millions of years. They believe that these asteroids may be the source of some of the dark NEOs found to be on long, highly inclined orbits.
The heat sensing capability of NEOWISE allowed scientists to measure the sizes of these asteroids more accurately. The scientists were also able to measure how much solar energy they reflect. NEOWISE can see dark objects far better than telescopes operating at visible wavelengths, which sense reflected sunlight.
The 1,400 Euphrosyne asteroids studied by the team of scientists were large and dark, with highly inclined and elliptical orbits. Therefore, scientists believe they may be the source of some of the dark NEOs previously detected by NEOWISE.
A better understanding of the Euphrosyne asteroids will give the scientists a clearer picture of the origin and behaviour of the asteroids in general and the NEOs in particular. Such studies are important to the safety of our home planet.
Featured image: The asteroid Euphrosyne glides across a field of background stars in this time-lapse view from NASA's WISE spacecraft (photo credit: JPL).