NASA and the European Space Agency (ESA) are preparing for the close approach of near-Earth object, asteroid 99942 Apophis.
In 2029, Apophis – believed to be one of the most hazardous asteroids to Earth when it was first discovered in 2004 – will come within 32,000 kilometers (20,000 miles) of the Earth’s surface, giving scientists the opportunity to study the object up close. Closer than some of our artificial satellites, the asteroid should be visible from the Eastern Hemisphere without the aid of a telescope or binoculars.
During the approach, Apophis will be influenced by Earth’s gravity.
Image credit: ESA
Five years ahead of the close approach, scientists have been proposing potential missions to study the asteroid at the Apophis T-5 Years: Knowledge Opportunity for the Science of Planetary Defense workshop organized by ESA.
NASA already has one visit to the asteroid planned, dubbed OSIRIS APEX. The mission will repurpose the asteroid sampler formerly known as OSIRIS-REx, sending it to greet the asteroid shortly after its flyby.
“Our planet’s gravitational pull is expected to alter the asteroid’s orbit, change how and how fast it spins on its axis, and possibly cause quakes or landslides that will alter its surface,” NASA explains of their planned mission. “OSIRIS-APEX will allow scientists on Earth to observe these changes. Additionally, the OSIRIS-APEX spacecraft will dip toward the surface of Apophis – a ‘stony’ asteroid made of silicate (or rocky) material and a mixture of metallic nickel and iron – and fire its engines to kick up loose rocks and dust. This maneuver will give scientists a peek at the composition of material just below the asteroid’s surface.”
At the ESA meeting, private companies proposed other missions to the asteroid, Space News reports.
Blue Origin’s idea is to use its Blue Ring spacecraft to deliver up to 13 payloads totaling up to 2 metric tons to the asteroid, launching in 2027 and approaching the asteroid shortly before its closest approach to Earth. Meanwhile, NASA’s Jet Propulsion Laboratory outlined its Distributed Radar Observations of Interior Distributions (DROID) mission.
“DROID’s architecture calls for a dedicated launch of three spacecraft: an ESPA Grande-class Mothership and two CubeSats,” JPL explains in a proposal. “The Mothership carries the CubeSats to Apophis, achieves the rendezvous cruise trajectory, performs high resolution imaging with a narrow-angle camera, and acts as a Direct-to-Earth (DTE) node for the constellation. Once Apophis’s physical characteristics (shape, spin, gravity field) are characterized sufficiently the Mothership deploys both CubeSats, which each carry a wide-angle camera and low-frequency radar (60 MHz, based on JuRa) and insert themselves into coordinated low orbits to perform monostatic and bistatic radar observations.”
While it is hoped that the flyby will help us learn more about planetary defense from such objects, there is nothing to fear from Apophis.
In 2021, Apophis made a flyby of Earth, at which point astronomers made powerful radar observations in order to better define its orbit. Before that, NASA believed that it had a chance of impact later in the century, but the observations ruled that out.
“A 2068 impact is not in the realm of possibility anymore,” Davide Farnocchia of NASA’s Center for Near-Earth Object Studies said of the asteroid, “and our calculations don’t show any impact risk for at least the next 100 years.”
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
