Say Goodbye to Earth’s Second Moon — It’ll Be Gone Soon
In the weird and constant news cycle of 2020, you may have missed some bizarre astronomical news: Researchers discovered an object called 2020 SO, which appeared to be a second moon in orbit around our planet. This object, known as the “minimoon”, had a story of its own. But now it’s about leaving our planet’s orbit and venturing into the darkness of space.
The 2020 SO object was first discovered in September 2020 as it approached Earth. It was initially thought of as an asteroid, but it was at a relatively low altitude – roughly half the distance between Earth and the (real, primary) moon. A debate ensued about what it was, and most astronomers decided it was likely artificial in nature.
Observations of the object began with tools like the Infrared Telescope Facility (IRTF), and eventually NASA explained that the object was actually a rocket booster from the 1960s. The researchers were able to match the composition of the object to a similar booster from the 1970s that was also in orbit.
On December 1, 2020, the 2020 SO object came closest to Earth and has been in Earth’s gravity ever since. But now it is loosening and moving into a new orbit around the sun. NASA created an animation to show the path the object is taking:
The object will make its final approach to Earth this week, February 2nd, and will be within 140,000 miles of the planet, according to EarthSky. But by March it will have freed itself from Earth’s gravity and instead will start a new course in orbit around the sun.
If you want to see this visitor from another time and say goodbye before he finally leaves our planet, the Virtual Telescope Project is holding a “Farewell, Mini Moon” event on February 1st. You can tune in to see a live feed of the property as it happened to us the last time.