After NASA crashes a car-sized spacecraft into an asteroid next week, it will be up to the European Space Agency’s Hera mission to investigate the “crime scene.”
After NASA intentionally crashes a car-sized spacecraft into an asteroid next week, it will be up to the European Space Agency’s HERA mission to investigate the “crime scene” and uncover the secrets of these potentially devastating space rocks.
NASA’s Double Asteroid Redirection Test (DART) aims to collide with asteroid Demorphos on Monday night, hoping to alter its course a bit — the first time such an operation has been attempted.
While Demorphos is 11 million kilometers (6.8 million miles) away and poses no threat to Earth, the mission is a test run in case the world ever needs to shove an asteroid off its course.
DART’s effect will be watched by astronomers around the world, and its impact will be closely watched to see if the mission passes the test.
Next, ESA’s Hera mission, named after the ancient Greek queen of the gods, will follow in the footsteps of this journey.
The Hera spacecraft is scheduled to launch in October 2024, with the goal of reaching Demorphos in 2026 to measure the exact impact that DART has had on the asteroid.
But scientists are excited not only to see the DART crater, but also to explore an object very far from this world.
– ‘new world’ –
Demorvos, which orbits the larger asteroid Didymos as they both dash through space, not only provides “the perfect testing opportunity for a planetary defense experience, but also an entirely new environment,” said Ian Carnell, ESA’s HERA mission manager.
HERA will be loaded with cameras, spectrometers, radars, and even toaster-sized nanosatellites to measure the asteroid’s shape, mass, chemical composition, and more.
It’s very important to understand the size and composition of such asteroids, said NASA’s Bhavya Lal.
“If an asteroid is made up of, say, loose pebbles, the ways to disrupt it may differ from whether it is a metal or another type of rock,” she told the International Astronautical Congress in Paris this week.
So little is known about Demorphos that scientists will be discovering a “new world” at the same time as the public on Monday, said Patrick Michel, the principal investigator for the Hera mission.
“Asteroids are not boring space rocks – they are very interesting because they have such a wide variety” of size, shape and composition, Michel said.
And because its gravity is low compared to Earth, the matter there can behave very differently than expected.
“Unless you touch the surface, you can’t tell the mechanical response,” he said.
– ‘Act like liquid’ –
For example, when a Japanese probe dropped a small explosive near the surface of the asteroid Ryugu in 2019, it was expected to make a crater two or three meters high. Instead, it made a 50-meter crater.
“There was no resistance,” Michel said.
He added that “the surface was behaving like a liquid,” not solid rock. “How strange is that?”
One of the ways the Hera Dimorphos mission will test is by landing a nano-satellite on its surface, in part to see how well it bounces.
Binary systems such as Dimorphos and Didymos account for about 15 percent of known asteroids, but they have not yet been explored.
At just 160 meters in diameter – roughly the size of the Great Pyramid of Giza – Demorphos would also be the smallest asteroid ever studied.
Recognizing the effect of DART is important not only for planetary defense, but also for understanding the history of our solar system, Michel said, since most cosmic bodies were formed through collisions and are now riddled with craters.
This is where DART and Hera can shed light not only on the future, but on the past.
#NASA #asteroid #collides #HERA #investigate #crime #scene