When a NASA spacecraft struck an asteroid, new images show fireworks

 

Credit: ASI/NASA

NASA's DART spacecraft collided with the asteroid Dimorphos on September 26 and was captured by telescopes on Earth and in space.According to NASA's associate administrator for science Thomas Zurbuchen, the collision was "the first human experiment to deflect a celestial body" and "an enormous success."

Andy Rivkin, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, who is working on the mission, says, "We’re all pretty stoked here."

LICIACube, a tiny Italian spacecraft that flew with DART and captured images of the 11 million kilometre-distance impact, provided a ringside view.The first images from LICIACube, which were published on September 27 by the Italian Space Agency, show Dimorphos being hit by DART and producing a massive, fireworks-like plume.Like a huge puff of smoke, the cloud of rocks and other debris expanded quickly.

Credit: ATLAS Project, University of Hawaii

Elisabetta Dotto, the science team leader for LICIACube at the National Institute for Astrophysics in Rome, stated at a press conference that the evolution of the plume will shed light on the physical properties of Dimorphos. Researchers are able to estimate how much of DART's kinetic energy was used to eject debris from Dimorphos and how much might have been used to alter the asteroid's orbit—the mission's objective—by examining how the plume formed and dispersed.

The spacecraft itself has been completed. According to physicist Megan Bruck Syal, who works at the Lawrence Livermore National Laboratory in California, "a lot of it is pulverized, and some of it is melted. "It's hard to say, but I doubt that any significant portions will remain.

Credit: NASA, ESA, Jian-Yang Li (PSI)/Animation by Alyssa Pagan (STScI)

LICIACube, Italy's first deep space mission, used autonomous guiding to keep its cameras focused on Dimorphos as it whizzed by 55 kilometers from the asteroid following the DART crash. It took pictures of Dimorphos before and after the crash with two cameras: one in black and white with the name LEIA and one in three colors with the name LUKE. The images show the plume expanding and drifting outward in the minutes that followed, beginning with a dramatic brightening at the time of impact. According to Bruck Syal, the debris plume's intricate structures, which in some places are almost "spidery," will assist modelers in comprehending the precise course of the impact.

Over 600 images are still stored on board LICIACube and are awaiting download to Earth in the coming weeks.

A ‘big jumble of rocks’

At 7.14 p.m. Eastern Standard Time, DART, which is the size of a golf cart, accomplished its goal of the Great Pyramid. A little over three hours later, the first images from LICIACube arrived at a control center in Turin, Italy.

Dimorphos is largely intact despite the enormous cloud of debris that was ejected. Another view of the impact that was captured by ground-based telescopes showed the plume puffing outwards as the rest of the asteroid hurtled onwards, confirming this.Since Dimorphos is currently only visible from the Southern Hemisphere, telescopes on Réunion Island in the Indian Ocean and South Africa made these initial observations. It is still being tracked by dozens of telescopes to see if its course has changed.

Credit: NASA/Johns Hopkins APL

Astronomers won't know for days or even weeks if DART was successful in its primary objective, which was to accelerate Dimorphos's orbit around Didymos, its partner asteroid, by at least 10 minutes. The purpose of the test, despite the fact that neither asteroid poses a threat to Earth, is to determine whether humans have the ability to alter an asteroid's trajectory in the event that a potentially hazardous space rock is discovered in the future heading toward Earth.

Before DART arrived, Dimorphos had never been seen up close. The asteroid's egg-shaped shape was discovered as the spacecraft got closer and closer to it. During its descent, DART took a series of pictures that showed that Dimorphos is also covered in boulders. Rivkin claims, "It's pretty clear that it's a pile of rubble. "merely a huge mess of rocks."