This is an artist's illustration of asteroid 2011 AG5. See the actual planetary radar observations in the image below.
NASA's Deep Space Network monitored one of the most long-lasting asteroids ever seen by planetary radar.
On February 3, an oblong asteroid, measuring more than three times its length as it is wide, safely flew past Earth at a distance of about 1.1 million miles (1.8 million kilometers, or a little less than five times the distance between the Moon and Earth).
The enormous 230-foot (70-meter) Goldstone Solar System Radar antenna dish at the Deep Space Network's facility near Barstow, California, revealed the dimensions of the highly elongated asteroid.
This is one of the most extended we've seen of the 1,040 near-Earth objects we've seen to date, according to Lance Benner, JPL's principal scientist who led the research.
a day after the asteroid made its close approach to Earth on February 3, the 2011 AG5 is one of the most elongated asteroids to be detected by planetary radar to date. Credit: NASA/JPL-Caltech
The Goldstone radar observations took place between January 29 and February 4, gathering additional data: 2011 AG5 has subtle dark and lighter areas that might suggest small-scale surface features a few hundred meters across. If the asteroid were seen by the human eye, it might appear as dark as charcoal.
The Goldstone radar observations reveal a key feature of the asteroid's orbit around the Sun. Scientists at NASA's Center for Near Earth Object Studies (CNEOS) will be able to determine the asteroid's orbital path in 2040.
"2011 AG5 became a poster-child asteroid shortly after its discovery when our analysis showed it had a small probability of an impact," said Paul Chodas, JPL's director of CNEOS. "These new ranging measurements will further refine where it will be far into the future."
The Goldstone Solar System Radar Group and CNEOS are supported by NASA's Near-Earth Object Observations Program at the agency's headquarters in Washington, D.C. The Deep Space Network receives programmatic oversight from the Space Communications and Navigation program office within the NASA Space Operations Mission Directorate.