Scientists hail DART success 6 months after historic asteroid crash

Five of the rocks on the beaten asteroid Dimorphos have been given new names.

Scientists declare that NASA's spectacular Double Asteroid Redirection Test (DART) was a resounding triumph.

Before the DART spacecraft purposefully collided with Dimorphos on September 26, 2022, scientists had little knowledge of the asteroid's dimensions, makeup, or form. Now, six months later, they can see its complete body, which is 580 feet (177 meters) broad, more clearly than ever before.

A new high-resolution mosaic of Dimorphos was unveiled on Monday (March 13) at the 54th Lunar and Planetary Science Conference (LPSC), which is taking place in Texas and online. Carolyn Ernst, a planetary scientist at The Johns Hopkins University Applied Physics Laboratory (APL), described the mosaic as looking like a happy fish swimming to the left with its nose kind of pointed up.

The mosaic was created using the last 10 pictures that the Didymos Reconnaissance and Asteroid Camera for Optical Navigation (DRACO), a camera mounted on DART, sent home. DRACO took a photograph of Dimorphos every second for the final four hours before DART collided with the planet.

Planetary scientist Nancy Chabot at APL said, "I knew the finished pictures were going to be magnificent, and they still managed to surpass my expectations. Chabot attributed the mission's success to the cooperation of a massive squad that included researchers from 100 schools in 28 different nations.

The collision of DART shortened Dimorphos' orbital period of Didymos, its bigger asteroid companion, by 33 minutes, to 11 hours and 23 minutes. Scientists used observatories on each of the seven continents to study the binary Didymos system in order to determine that number.

The Planetary Data Center of NASA now has more than 259,000 pictures taken by DRACO online (opens in new tab). Researchers were able to corroborate that Dimorphos is a pile of debris thanks to these pictures, which also show some of the 2.2 million pounds (1 million kilograms) of ejecta that were propelled off Dimorphos by the collision.

With the aid of this information, researchers were able to recreate the collision and the closing seconds of DART. According to Ernst, the probe's intended impact location measured 25 inches (66 centimeters) in width. The star tracker that was shooting out from the bottom of the probe was probably the first component to be struck because that is smaller than the cross section of DART. DART's solar panels collided with a boulder on Dimorphos microseconds later, but there was no time for one component of the spaceship to alert the others to the impact, according to Ernst.

The titles of five characteristics on Dimorphos' surface have been approved by the International Astronomical Union (IAU), which is in charge of naming celestial objects, scientists also reported on Monday.

The Hubble Space Telescope observations of the ejecta and tail formations, as well as DART's closing seconds, were some of the new study that was shared. These results, which were released on March 1st, highlighted the expedition as the first to observe Dimorphos develop not one, but two tails. (Previously, scientists had seen tails on asteroids, but they had never actually seen one develop.) Didymos will be watched by the Hubble Space Telescope until it is too near to the sun to do so securely, which will occur in early July.

Additionally, according to scientists, when DART impacted between Atabaque and Bodhran on Dimorphos, it left a crater between 130 and 196 feet (40 and 60 meters) in width.

LICIACube (short for "Light Italian Cubesat for Imaging of Asteroids"), a 31-pound (14 kilogram), smaller-than-a-shoebox satellite that rode DART and moved away to a safe distance two weeks before impact, observed the entire spectacle firsthand. The brilliant flash that occurred immediately after DART's collision with Dimorphos was among the many images the satellite captured.

"From a science standpoint, it is really a treasure collection," said Maurizio Pajola, a member of the LICIACube Science Team and a planetary scientist at the Italian National Institute for Astrophysics.

The mission crew earlier in March received the 2023 Nelson P. Jackson Aerospace Award from the National Space Society and Foundation for DART's "outstanding service" to the space industry.

Scientists said that while the information gleaned from DART's success up to this point is crucial, it is insufficient on its own to comprehend the mission's significance in the wider framework of planetary defense. More investigation will be needed in order to apply a similar "kinetic impactor" method to another asteroid threat, and continuing study into how the ejecta from such an impact will behave and evolve will be crucial, they said.

Scientists hope to gain a better understanding of what to anticipate when the Hera mission from the European Space Agency arrives at the Didymos-Dimorphos system in 2026 using all the data that DART sent home as well as additional information being gathered by ground-based observatories.