NASA’s OSIRIS-REx spacecraft, fresh off its successful mission to collect samples from the asteroid Bennu, is now gearing up for its next assignment – studying another asteroid during its upcoming close encounter with Earth.
After completing its seven-year, 4 billion-mile journey to collect samples from Bennu, the spacecraft has been repurposed to study the asteroid Apophis, which is expected to come closer to Earth in 2029 than any other similarly-sized asteroid in recorded history. The mission has been renamed OSIRIS-APEX (Origins, Spectral Interpretation, Resource Identification, and Security – Apophis Explorer) in light of this new assignment.
Apophis, a more than 1,000-foot-wide asteroid named after an Egyptian deity and nicknamed the “God of Chaos,” is expected to pass within 20,000 miles of Earth’s surface on April 13, 2029, in what scientists are calling a historically close encounter. Such asteroids only pass this closely once every 7,500 years, according to scientific estimates.
The close approach of Apophis to Earth will offer unique research opportunities. “The close approach is a great natural experiment,” said Dani Mendoza DellaGiustina, principal investigator for OSIRIS-APEX. “We know that tidal forces and the accumulation of rubble pile material are foundational processes that could play a role in planet formation. They could inform how we got from debris in the early solar system to full-blown planets.”
In light of the close encounter, NASA’s OSIRIS-APEX will take pictures of Apophis about two weeks before it passes Earth and then arrive at the asteroid on April 13, 2029, to stay with it for the next year and a half, studying any changes caused by the close encounter. Unlike its previous mission to Bennu, OSIRIS-APEX won’t make contact with Apophis. Instead, the spacecraft will drop within 16 feet of the asteroid’s surface and fire its thrusters to stir up rocks and dust, giving scientists a glimpse of what lies beneath.
NASA is optimistic that this new mission will lead to a host of new discoveries, with the project scientist, Amy Simon, saying, “We learned a lot at Bennu, but now we’re armed with even more questions for our next target.”