A giant asteroid is approaching Earth. Be excited, not scared.

Apophis is a once-in-a-lifetime opportunity to study an asteroid like never before. Observing Apophis up close will help scientists figure out how to protect our planet from future asteroids that could hit Earth.

But space missions take years to develop, and Apophis is less than five years away from approaching Earth.

“We’re running out of time,” said Jason Kalirai, director of space formulation at the Johns Hopkins Applied Physics Laboratory.

Meet Apophis

Apophis is about the same width as the Eiffel Tower is tall, and although scientists have yet to take a picture of the asteroid, they have used radar data to estimate that it is roughly the shape of a peanut.

While the asteroid, which scientists believe has two lobes, has been living a peaceful life in space, that wasn’t the case when it was discovered by scientists at Kitt Peak National Observatory in June 2004. Later that year, researchers calculated that there was a 2.7 percent chance that the asteroid would result in a violent collision rather than a harmless flyby when it encounters Earth in 2029.

“If it hits a densely populated area, it could potentially destroy a city the size of New York,” said Daniella DellaGiustina, chief scientist for NASA’s Apophis mission (OSIRIS-APEX).

Apophis made such a bad first impression that it was named after the Egyptian snake god of darkness and chaos.

It wasn’t until March 2021 that scientists were able to rule out the possibility that Apophis would collide with Earth within at least the next 100 years. Using a 70-meter radio antenna in California, scientists gathered the data they needed to clear Apophis’ name and remove it from NASA’s Sentinel Impact Risk Table, a list of asteroids that could potentially impact Earth within the next century.

Apophis will be within 32,000 kilometers of Earth, give or take a few miles. When two objects are close together in space, they exert forces on each other. Just as Earth is subject to tidal forces from the Moon, so too will Apophis be subject to tidal forces from Earth.

The Moon’s gravity causes tides on Earth, while Earth’s gravity could cause small earthquakes on Apophis. A flyby of Apophis would mark the first opportunity to observe seismic activity on an asteroid.

Asteroid Space Chase

Now that scientists know Apophis won’t collide with Earth, they’ve turned their attention to another problem: How to reach Apophis in time.

“What did we do with Apophis? I don’t think enough was done,” Carile said.

Although Apophis has fascinated us for 20 years, no one knows exactly what it looks like. Many of its basic properties remain unknown, including its mass and structure.

Earth’s planetary defense capabilities have been tested recently NASAThe Double Asteroid Redirection Test (DART), in which Johns Hopkins University researchers successfully slammed a spacecraft into an asteroid to change its orbit.

While researchers are proud of Dart, they emphasize that Earth’s self-defense toolkit is not complete. Planetary defense is more than just delivering a celestial uppercut. Scientists need to be able to locate asteroids and study their properties to mount an effective response.

“Apophis is an opportunity to practice what types of characterization work we can do to better understand a particular object. We can learn from it when we find asteroids flying toward us in the future,” said Terrick Daly, a planetary scientist on Dart and the OSIRIS-Apophis mission.

NASA’s Osiris-Apex mission will redirect existing spacecraft to characterize Apophis after its closest approach to Earth. The mission will use high-resolution images of Apophis’ surface to study how the asteroid is affected by Earth’s gravity.

The OSIRIS-APEX spacecraft can also use its thrusters to kick up dust on the asteroid. With this capability, scientists will get a sense of the strength of Apophis’ surface, which will inform how to deflect the asteroid in the future if necessary.

If the asteroid’s surface is hard and not easily broken up, then an impact method like Dart may not be effective in changing the asteroid’s orbit.

Observing asteroids carefully could also help answer long-standing questions about the solar system, including where Earth’s water came from. By comparing water on Earth to water on asteroids, scientists can look for similarities that could help them understand how this important resource came to our planet billions of years ago.

But OSIRIS-Apophis can’t go it alone. With the mission’s spacecraft already in orbit and limited fuel, it can only reach Apophis in June, two months after its closest approach to Earth.

If scientists are to fully understand Apophis and how it is affected by Earth, they need to study it both before and during its closest approach to Earth.

So far, OSIRIS-APEX is the only confirmed and fully funded Apophis mission.

“No money, no Bruce Willis”

At the two-day Apophis T-5 annual workshop, scientists proposed a total of more than 20 spacecraft and payloads to promote international cooperation on the Apophis mission.

“Ideally, we would have a fleet of vehicles going to Apophis,” Kalirai said. But scientists have less than five years to develop, build and launch the vehicles.

In addition to time, there is a lack of money to fund the Apophis mission.

“Without the money, there’s no Bruce Willis,” Binzel said.

As a result, many scientists are trying to repurpose old tasks to save time and money.

Experts urged NASA to study the Janus spacecraft before the Apophis flyby, which was originally scheduled to launch as part of another mission in 2023. Since that mission was delayed, both spacecraft have been put on hold indefinitely.

Scientists on the Apophis T-5 probe described the pre-flight encounter with Apophis as a search mission for a spacecraft. They believe that the Janus satellite could meet this need, and that the Janus satellite is the search mission spacecraft.

Blue Origin, the private space company founded by Jeff Bezos, reported that its Blue Ring spacecraft could encounter Apophis three months before its flyby. The spacecraft has 13 payload slots, allowing multiple parties to share the cost of the mission. (Bezos owns Washington post.

Of all the proposals circulating, the mission developed by the European Space Agency is closest to realization. Similar to Osiris-Apex, ESA’s rapid Apophis space safety mission Ramses uses technology developed for the Hera mission, which is expected to launch this year to study the aftermath of Dart.

Ramses will encounter Apophis two months before its flyby and closely observe how it is affected by Earth’s gravity. The mission will monitor how Earth changes Apophis’s rotation, which has a significant impact on the asteroid’s future orbit.

The Space Safety Program Committee has given ESA the go-ahead to start the mission. Ramses, however, is not yet certain: the mission is awaiting final funding approval from ESA’s Council of Ministers, which will make a decision by the end of next year.

While space exploration is technically complex, many advances have been made that make more missions possible and successful. Scientists have even launched a spacecraft to dig up an asteroid and bring its fragments back to Earth. Therefore, much of the technology needed to explore Apophis already exists, making the bottleneck mainly funding.

Although the probability of the Earth encountering an asteroid capable of causing mass extinction in the short term is almost zero, there is a 100% chance that The probability that a devastating asteroid will hit Earth at some point.

“The question is when and if we can stop this before it happens,” said Bruce Bates, chief scientist at the Planetary Society, which advocates for space exploration.

Unlike most natural disasters, asteroid collisions are avoidable if the tools are available to track space rocks and take self-defense action if necessary.

Building Earth’s planetary defense toolkit isn’t motivated by fear, Binzel said. “It’s just smart responsibility.”

Joel Achenbach contributed to this report.