FILE - On August 20, 1975, Viking 1 was launched by a Titan/Centaur rocket from Complex 41 at Cape Canaveral Air Force Station in Florida at 5:22 p.m. EDT to begin a half-billion mile, 11-month journey through space to explore Mars. The 4-ton spacecraft went into orbit around the red planet in mid-1976.  (Image Credit: NASA)
FILE - On August 20, 1975, Viking 1 was launched by a Titan/Centaur rocket from Complex 41 at Cape Canaveral Air Force Station in Florida at 5:22 p.m. EDT to begin a half-billion mile, 11-month journey through space to explore Mars. (Image credit: NASA)

A scientist from the U.S. space agency says what was thought to be a small asteroid heading towards Earth may actually be a 54-year-old section from a rocket coming back home. 

The head of NASA’s Center for Near-Earth Object Studies (CNEOS), Paul Chodas, told the Associated Press the object was first spotted by a telescope in Hawaii last month as part of the ongoing effort to monitor space objects that may pass close to Earth and possibly pose a threat. 

Chodas said further observations of the object, named Asteroid 2020 SO, indicated it had that a near-circular orbit around the sun, similar to Earth’s, an unusual characteristic for an asteroid, and a first clue that it might have originated from here. 

Chodas said the object is also in the same orbital plane as Earth, not tilted above or below, while asteroids that originate in deep space the sun orbit at odd angles. Finally, its speed approaching Earth is about 2,400 kilometers per hour, slow by asteroid standards. 

The NASA scientist speculates 2020 SO is actually the upper stage of a Centaur rocket that successfully propelled NASA’s Surveyor 2 unmanned lunar probe to the moon in 1966 before it was discarded.  

The lander had been designed to land on the moon but crashed there after one of its thrusters failed.  The rocket, meanwhile, swept past the moon and into orbit around the sun as it was designed to do. 

Asteroid 2020 SO is estimated to be roughly eight meters long, based on its brightness, which would be roughly the size of the Centaur rocket section, which would be less than ten meters long and three meters in diameter.  

Chodas has made a personal hobby of trying find such discarded pieces of NASA history, and is excited about confirming his speculation as the object gets closer. He predicts once it gets close enough next month, Asteroid 2020 SO will be captured in Earth’s orbit and spend about four months circling Earth before shooting back out into its own orbit around the sun.