NASA’s OSIRIS-REx spacecraft recently delivered a precious bounty – sending a sample collected from asteroid Bennu as it zipped through Earth’s atmosphere and landed in the Utah desert. A team immediately picked up the sample and took it for analysis, and enjoyed the largest sample ever collected from an asteroid.
But the spacecraft did not land on Earth with the samples. Rather, it released the sample as it passed Earth and continued its journey. Although the spacecraft only had the capability to collect a single sample, it carried a full suite of scientific instruments. So instead of letting it go to waste, the spacecraft will now move on to investigate another asteroid. Its new mission is also marked by a new name: the spacecraft is now OSIRIS-APEX.
The spacecraft will now travel to visit asteroid Apophis, best known as a near-Earth asteroid that was once thought to be in danger of impacting planet Earth. Recent measurements have shown that we are not in danger of an impact in the near future, but the asteroid may still be passing close to our planet.
“Apophis is a notorious asteroid,” the OSIRIS-Apex mission’s new principal investigator, Dani Dellagistina of the University of Arizona, said in a statement. “When it was discovered in 2004, there were fears that it was going to impact Earth in 2029, but that risk was averted. Then there was another fear that it was going to impact Earth exactly seven years later, in 2036, but now observations combined with modeling suggest that Apophis poses no threat for at least the next hundred years. Despite this, Apophis still has this role in the psyche of all of us who study these things. “Although it is not going to impact Earth in 2029, it still comes very close.”
Osiris-Apex will meet Apophis in April 2029 when it comes within 20,000 miles of Earth. The asteroid is about 340 meters wide, and asteroids of this size come this close to Earth only once every 7,500 years. It is believed to be an S-type asteroid, meaning it is composed of silicate or rocky materials, like the asteroid Bennu. Researchers want to know how strong and dense an asteroid is, which is important both for future planetary defense planning and for understanding how asteroids form and evolve.
By combining data on Bennu and Apophis, researchers can learn more about asteroids that could one day threaten Earth. “We learned a lot at Bennu, but now we’re armed with even more questions,” said Amy Simon, OSIRIS-APEX mission project scientist.