ESA’s Hera spacecraft set to conduct asteroid ‘crime scene investigation’

Europe’s Hera probe is tentatively scheduled to launch Monday to inspect the damage caused by a NASA spacecraft when it crashed into an asteroid in the first test of Earth’s planetary defenses.

In a scene that seems straight out of science fiction, the spacecraft deliberately crashed into the pyramid-sized asteroid Dimorphos in 2022, about 11 million kilometers (6.8 million miles) away. ) of the Earth.

The refrigerator-sized impactor used in the Double Asteroid Redirection Test (DART) successfully knocked the asteroid off course.

This demonstrated that the idea worked: humanity may no longer be helpless against potentially planet-destroying asteroids that could approach in the future.

But much about the impact remains unknown, including the extent of the damage caused and the exact state of the asteroid before it was hit.

So the European Space Agency announced it would send Hera to the asteroid to conduct a “crime scene investigation” in hopes of finding out how Earth can best fend off asteroids that pose a threat.

The spacecraft is scheduled to blast off on Monday aboard a SpaceX Falcon 9 rocket from Cape Canaveral in the US state of Florida.

An “anomaly” could delay the launch

However, an “anomaly” involving a Falcon 9 rocket during Saturday’s launch of SpaceX’s Crew-9 astronaut mission could potentially delay the launch date, Ian Carnelli, ESA’s Hera project manager, said during a press conference.

The ESA hopes to receive approval by Sunday from the U.S. Federal Aviation Administration, NASA and SpaceX, Carnelli said.

The mission launch window will remain open until October 27.

Once launched, Hera is expected to fly by Mars next year, then arrive near Dimorphos in December 2026 to begin its six-month investigation.

A kilometer (0.6 mile) wider asteroid – which could trigger a global catastrophe on a scale such as the extinction of the dinosaurs – is estimated to hit Earth about every 500,000 years.

An asteroid about 140 meters (460 feet) wide – which is a bit smaller than Dimorphos but could still destroy a major city – hits our planet about every 20,000 years.

Most of these celestial objects come from the asteroid belt between Mars and Jupiter. Almost all of them more than a kilometer wide are known to scientists, and none are expected to threaten Earth over the next century.

There are also no 140 meter asteroids on a collision course with Earth, but only 40% of these space rocks are thought to have been identified.

Although asteroids are one of the least likely natural disasters to hit the planet, humans now have “the advantage of being able to protect against them,” said Patrick Michel, principal investigator of the Hera mission.

Rubble ‘defies intuition’

Dimorphos, which is actually a moon orbiting its big brother Didymos, has never posed a threat to Earth.

After the DART impact, Dimorphos lost material to the point that its orbit around Didymos was shortened by 33 minutes, proof that it was successfully deflected.

Analysis from the DART mission suggested that rather than being a single hard rock, Dimorphos was instead a pile of rubble held together by gravity.

“The consequence of this is that instead of creating a crater” on Dimorphos, DART could have “completely distorted” the asteroid, Michel explained.

But there are other possibilities, he said, adding that the behavior of these low-gravity objects is little understood and “defies intuition.”

The mission, costing 363 million euros ($400 million), will be equipped with 12 scientific instruments and two nanosatellites.

The Juventas nanosatellite will aim to land on Dimorphos, which would be a first on such a small asteroid. It will use radar to probe deep into the asteroid’s interior and a gravimeter to measure its gravity.

From further afield, the Milani nanosatellite will use cameras and other instruments to study the asteroid’s composition and assess the impact of DART.

Once their work is done, the team on the ground hopes that Hera will be able to land gently on Dimorphos or Didymos, where she will spend the rest of her days.

© 2024 AFP