Asteroid's potato shape revealed as it zips past Earth
Sen—As a large asteroid, 2014 HQ124, sped close by the Earth on Sunday (8 June), several telescopes on the ground teamed up to get radar images. The result shows an odd potato-shaped object that could be a single asteroid, or two smaller ones that are closely linked with each other.
"This may be a double object, or 'contact binary,' consisting of two objects that form a single asteroid with a lobed shape," said Lance Benner, a scientist at NASA's Jet Propulsion Laboratory, who co-led the research with fellow JPL scientist Marina Brozovic.
The 370 metre (1,300 ft) wide asteroid's closest approach to Earth was about three times the distance from our planet to the Moon. Images were obtained when the asteroid was between 1.39 million km and 1.45 million km (864,000 miles and 902,000 miles) from Earth and show features as small as 3.75 metres (12 ft) across.
Radar not only revealed the size of the asteroid's markings, but hinted at its rate of rotation. Across 4.5 hours of observations, scientists said the movement of the object suggested that its rotation period is approximately 24 hours—a single Earth day.
Radar images of asteroid 2014 HQ124 taken on June 8, 2014. Image credit: NASA/JPL-Caltech/Arecibo Observatory/USRA/NSF
It was a bit of a scramble to get the images, as the asteroid was only discovered on 23 April, 2014. Scientists linked the 70-meter (230ft) Deep Space Network antenna in Goldstone, Calif. with two other telescopes (but only one of those telescopes at the time).
One of the observatories taking part was the large telescope at the Arecibo Observatory in Puerto Rico, which has been used in movies ranging from Contact (1997) to the James Bond movie GoldenEye (1995). The 305-metre (1,000ft) dish is large, but also fixed.
The other observatory was a smaller antenna that was 34 metres (112ft) across and located about 32 km (20 miles) away from Goldstone.
"Using this technique, the Goldstone antenna beams a radar signal at an asteroid and the other antenna receives the reflections. The technique dramatically improves the amount of detail that can be seen in radar images," said a NASA spokesman.
Radar observations of asteroid 2014 HQ124 show an irregular, elongated object. Credit: NASA/JPL
NASA's efforts to image the asteroid are a part of its larger effort to better track and characterise near-Earth objects. The agency is one of several international entities working to figure out how threatening asteroids and other small objects can be to Earth's survival in the long term.
As a part of that, the agency is hoping to send astronauts to an asteroid in the coming years. The goal will be for a spacecraft to visit an asteroid and tow it closer to Earth for astronauts to explore.
In late March, NASA said it would offer up to US$6 million (£3.54 million) for concepts ranging from asteroid capture systems to sensors to get close to the asteroid to commercial spacecraft design.