NASA’s OSIRIS-REx mission, now known as OSIRIS-APEX, is preparing to investigate Apophis, a celestial object named after the ancient Egyptian god of chaos and darkness. This mission is scheduled for approximately 5 ½ years from now, when Apophis will approach within 20,000 miles of Earth on April 13, 2029. OSIRIS-APEX, short for Origins, Spectral Interpretation, Resource Identification, and Security-APophis Explorer, will closely orbit Apophis for 18 months, aided by Earth’s gravity. The primary purposes are to conduct scientific research and enhance Earth’s defense mechanisms against potential asteroid threats. Although OSIRIS-APEX won’t collect samples from Apophis like its predecessor did with Bennu, it will employ gas thrusters to stir up dust and rocks for study. Comparing Apophis, an S-type asteroid, to Bennu’s C-type composition will provide valuable insights into stony asteroid structure and potential impacts on Earth, contributing to planetary defense strategies.

Dani DellaGiustina, OSIRIS-APEX’s principal investigator, notes that Apophis is a well-known asteroid. While initial concerns about an impact in 2029 have been dispelled, Apophis will make an incredibly close approach, coming within one-tenth the distance between Earth and the moon, a unique scientific observation opportunity. During the 2029 encounter, people in Europe and Africa will even be able to spot Apophis with the naked eye. Continuous monitoring of Apophis will supply essential data about its orbit, surface, and rotation rate, ensuring Earth’s safety from potential future asteroid impacts.