Astronomers are getting a chance to view one of the clearest images ever taken of an asteroid as it glides silently past Earth.
Scientists Marina Brozovic and Lance Benner of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., used Earth-based radar to capture clear images of the near-Earth object classified as 2014 HQ124. The 21 radar images, taken over a period of four-and-a-half hours, were captured on June 8, 2014, NASA said in a statement.
During the four-and-a-half hour time span, the asteroid rotated a few degrees per frame, suggesting to NASA scientists that its rotation period is a little less than 24 hours. The asteroid appears to be an elongated, irregularly shaped object that is at least 1,200 feet (370 meters) wide on its long axis, according to Benner.
“This may be a double object, or ‘contact binary,’ consisting of two objects that form a single asteroid with a lobed shape.”
On June 8, asteroid 2014 HQ124 made its closest approach to Earth, coming within 776,000 miles (1.25 kilometers), three times more distant than the moon. The new observations reveal features as small as 12 feet (3.75 meters) wide.
To get these new images, researchers paired together the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif., with two other radio telescopes, one at a time, the space agency said. As the Goldstone antenna beams radar signals at an asteroid, the other antenna receives the reflections. This technique significantly improves the amount of detail that can be seen.
First, the Goldstone antenna was paired with the 1,000 foot (305-meter) Arecibo radio telescope located in Puerto Rico. Then they paired Goldstone with a smaller 112-foot (34-meter) antenna some 20 miles away, NASA explained. A recent upgrade in equipment at the Arecibo site allowed the two facilities to work together for the first time and produce images with stunning detail.
“By itself, the Goldstone antenna can obtain images that show features as small as the width of a traffic lane on the highway,” said Benner. “With Arecibo now able to receive our highest-resolution Goldstone signals, we can create a single system that improves the overall quality of the images.”
NASA is putting substantial resources into understanding asteroids, the agency said. Through its Asteroid Initiative, scientists are working on a first-of-a-kind mission to identify, capture with robotic spacecraft, and redirect a potentially-destructive asteroid into a stable orbit around the moon.