On August 19th this year, astronomers using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) observatory in Hawaii spotted an object destined to enter Earth orbit this fall. Designated as object 2020 SO, the item is now believed to be a rocket booster from NASA’s Surveyor 2 mission which crash landed on the Moon in 1966 during the Apollo-era of the Cold War’s space race.
“I suspect this newly discovered object 2020 SO to be an old rocket booster because it is following an orbit about the Sun that is extremely similar to Earth’s, nearly circular, in the same plane, and only slightly farther away the Sun at its farthest point,” Dr. Paul Chodas, the director of NASA’s Center for Near Earth Object Studies, explained in comments to CNN.
“That’s precisely the kind of orbit that a rocket stage separated from a lunar mission would follow, once it passes by the Moon and escapes into orbit about the Sun. It’s unlikely that an asteroid could have evolved into an orbit like this, but not impossible,” he said.
This specific type of event has only happened once before, namely in 2002 with a Saturn V upper stage from Apollo 12, according to Dr. Chodas. Of course, there’s still a chance that 2020 SO is actually an asteroid, in which case it would be considered a minimoon while in direct orbit around the Earth. However, an old rocket booster finding would merely be considered ‘space junk’ and join the 57,000-plus pieces of human debris currently being tracked by various entities.
“In a month or so we will get an indication of whether or not 2020 SO really is a rocket body, since we should start being able to detect the effect of sunlight pressure has on the motion of this object: if it really is a rocket body, it will be much less dense than an asteroid and the slight pressure due to sunlight will produce enough change in its motion that we should be able to detect it in the tracking data,” Dr. Chodas explained. Regardless of designation, 2020 SO will leave Earth’s orbit in February 2021.
The United States’ victory over the Soviet Union in landing the first humans on the Moon in July 1969 generally overshadows the rest of that portion of the space race in the 1960s. Russian probes reached the lunar surface first, one impacting in 1959 and the other landing in February 1966. Surveyor 1 landed on the Moon on June 2, 1966 to collect photographs for the Apollo program’s landing sight assessment; Surveyor 2, as detailed above, never completed its mission after launching aboard an Atlas LV-3C Centaur-D rocket.
One astronomer’s space ‘trash’ is a vintage space collector’s treasure? You decide. You can watch more on NASA’s Surveyor missions below: