The NASA probe that delivered precious samples of the space rock Bennu to Earth is now on an prolonged voyage to review an infamous near Earth asteroid.
OSIRIS-REx accomplished NASA’s first asteroid sample return mission on Sunday (Sept. 24), when its reentry capsule landed within the western Utah desert. But now the most important spacecraft has launched into a side quest: to scope out and stand up close with Apophis, an asteroid previously thought to potentially pose a threat to Earth.
The spacecraft used its return to Earth to fling itself on a course toward Apophis. It fired its engines about 20 minutes after releasing the reentry capsule containing pristine material from the early solar system, effecting a trajectory change and setting it on one other long, looping voyage.
Related: Apophis: The infamous asteroid we thought might hit us
That complex journey will take OSIRIS-REx much closer to the sun than it was originally designed to get, passing throughout the orbit of Venus quite a lot of times and revisiting Earth, eventually allowing it to finally rendezvous with Apophis. It’s planned to achieve the article, also referred to as asteroid 99942, on April 8, 2029.
OSIRIS-APEX is not going to collect samples from Apophis, but it’ll study the asteroid for 18 months. These proximity operations will include imaging and mapping the asteroid and a close-up rendezvous maneuver just like the one used to acquire material from Bennu in October 2020. While we cannot get to investigate parts of Apophis on Earth, this move will give unique insights into its subsurface, composition and properties.
Apophis is an intriguing and high-profile near Earth object (NEO). The roughly 1,100 feet (340 meters) object was once thought to have a probability of smashing into Earth in 2068. Apophis is not any longer considered a threat, and the celestial dance of the solar system will as a substitute offer a probability to stand up close with this former nemesis.
Apophis’ next close approach to Earth will see it get inside around 20,000 miles (32,000 kilometers) of us on Friday, April 13, 2029. While an inauspicious date to some, it presents humanity with a terrific opportunity to review the space rock and learn more about not only asteroids but in addition the evolution of the solar system.
Apophis is a “typical” near-Earth asteroid, Olivier Hainaut, an astronomer working on NEOs on the European Southern Observatory (ESO), told Space.com.
“By studying it, we are going to learn more about these objects, most of which were formed at the identical place because the Earth,” Hainaut said. “In a way, you may have a look at Apophis and the NEOs as crumbs left over while making the Earth.”
Bennu is a carbon-rich, B-type asteroid, but Apophis is an S-type, or “stony” asteroid composed mainly of silicate and nickel iron. These relics of that primordial era are common within the inner solar system and will yield untold secrets of the origins of the planets and the processes that led to their formation.
Due to its common properties, it’ll even be useful for planetary protection efforts. “It’s super interesting scientifically and super-interesting for the protection of the Earth,” Hainaut said. “While Apophis just isn’t dangerous, we expect it to be very much like other NEOs that would collide with the Earth.”
But an asteroid is probably not what it appears, as OSIRIS-REx found at Bennu: That space rock’s surface behaved, surprisingly, like a ball pit. We cannot know what Apophis is like until the probe gets up close and private with it.
And OSIRIS-APEX is probably not the one visit to Apophis, if scientists get their way.
NASA’s Small Bodies Assessment Group recently called for the agency to discover a strategy to fly by Apophis before its close encounter with Earth. This may “provide a whole investigation of this remarkable opportunity to quantify and understand in real time the implications of planetary tides on the evolution of asteroids and glean vital information on Apophis’ interior structure, which is otherwise unobtainable,” the group stated.
Elsewhere, a workshop is being organized for 2024 to explore international collaboration opportunities for each Earth-based observations and potential in situ investigations of Apophis.
Whether these extra missions occur or not, OSIRIS-APEX will provide more pieces of the puzzle, helping researchers understand the primordial objects in our neighborhood, our planet and tips on how to protect it.