New observations by NASA's Goldstone Solar System Radar in California, Arecibo Observatory in Puerto Rico and the Green Bank Observatory in West Virginia have revealed that the recently-discovered near-Earth asteroid 2017 YE5 is actually two objects - each about 3,000 feet (900 m) in size - orbiting each other. But the scientists couldn't tell if the two bodies were joined or separate until asteroids rotated; then the scientists were able to spot the gap.
Binary systems are typically between a larger asteroid and a smaller asteroid.
The asteroid was first spotted by the Morocco Oukaimeden Sky Survey in December of 2017. The effort confirmed the two lobes are separated and orbiting around one another.
After checking the results of observations, NASA announced that an asteroid 2017 YE5 is two objects, writes the online edition of the Chronicle.info with reference for a New time.
Then the Arecibo Observatory in Puerto Rico and the Green Bank Observatory in West Virginia did something incredible: using a technique called "bi-static radar configuration" Arecibo broadcasted a radar signal to detect 2017 YE5, which Green Bank then received. However, on June 21, 2018, as the asteroid came within 16 times the distance of the Earth to the Moon, astronomers at NASA's Goldstone Solar System Radar (GSSR) in California took advantage of the opportunity and conducted a series of radar observations. Together, they would study the asteroid using a bi-static radar configuration, in which radar signals are bounced off the asteroid by Arecibo and received by GBO.
The Arecibo, Goldstone and USRA planetary radar projects are funded through NASA's Near-Earth Object Observations Program within the Planetary Defense Coordination Office (PDCO), which manages the Agency's Planetary Defense Program.
Within two days both observatories declared that 2017 YE5 was the rare binary asteroid they'd been looking for.
Its dual nature wasn't the only odd attribute to come to light, either. The new observations revealed their true size, and scientists believe they're likely made of a dark material that doesn't reflect as much sunlight as a standard asteroid, leading to the original incorrect estimate. Researchers think the asteroids "may have different densities, compositions near their surfaces, or different surface roughnesses".
The video below discusses 2017 YE5. But if both asteroids are of almost equal size then the foci of their orbit sit in empty space, with neither asteroid acting as the center.