After 10 months flying in space, NASA’s Double Asteroid Redirection Test (DART) – the world’s first planetary defense technology demonstration – successfully impacted its asteroid target on Monday, the agency’s first attempt to move an asteroid in space.
Mission control at the Johns Hopkins
Applied Physics Laboratory (APL) in Laurel, Maryland, announced the successful
impact at 7:14 p.m. EDT.
As a part of NASA’s overall planetary defense strategy, DART’s impact with the
asteroid Dimorphos demonstrates a viable mitigation technique for protecting
the planet from an Earth-bound asteroid or comet, if one were discovered.
“At its core, DART represents an
unprecedented success for planetary defense, but it is also a mission of unity
with a real benefit for all humanity,” said NASA Administrator Bill Nelson. “As
NASA studies the cosmos and our home planet, we’re also working to protect that
home, and this international collaboration turned science fiction into science
fact, demonstrating one way to protect Earth.”
DART targeted the asteroid moonlet
Dimorphos, a small body just 530 feet (160 meters) in diameter. It orbits a
larger, 2,560-foot (780-meter) asteroid called Didymos. Neither asteroid poses
a threat to Earth.
The mission’s one-way trip confirmed NASA
can successfully navigate a spacecraft to intentionally collide with an
asteroid to deflect it, a technique known as kinetic impact.
The investigation team will now observe
Dimorphos using ground-based telescopes to confirm that DART’s impact altered
the asteroid’s orbit around Didymos. Researchers expect the impact to shorten
Dimorphos’ orbit by about 1%, or roughly 10 minutes; precisely measuring how
much the asteroid was deflected is one of the primary purposes of the
full-scale test.
“Planetary Defense is a globally unifying
effort that affects everyone living on Earth,” said Thomas Zurbuchen, associate
administrator for the Science Mission Directorate at NASA Headquarters in
Washington. “Now we know we can aim a spacecraft with the precision needed to
impact even a small body in space. Just a small change in its speed is all we
need to make a significant difference in the path an asteroid travels.”
The spacecraft’s sole instrument, the
Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO),
together with a sophisticated guidance, navigation and control system that
works in tandem with Small-body Maneuvering Autonomous Real Time Navigation
(SMART Nav) algorithms, enabled DART to identify and distinguish between the
two asteroids, targeting the smaller body.
These systems guided the 1,260-pound
(570-kilogram) box-shaped spacecraft through the final 56,000 miles (90,000
kilometers) of space into Dimorphos, intentionally crashing into it at roughly
14,000 miles (22,530 kilometers) per hour to slightly slow the asteroid’s
orbital speed. DRACO’s final images, obtained by the spacecraft seconds before
impact, revealed the surface of Dimorphos in close-up detail.
Fifteen days before impact, DART’s CubeSat
companion Light Italian CubeSat for Imaging of Asteroids (LICIACube), provided
by the Italian Space Agency, deployed from the spacecraft to capture images of
DART’s impact and of the asteroid’s resulting cloud of ejected matter. In tandem
with the images returned by DRACO, LICIACube’s images are intended to provide a
view of the collision’s effects to help researchers better characterize the
effectiveness of kinetic impact in deflecting an asteroid. Because LICIACube
doesn’t carry a large antenna, images will be downlinked to Earth one by one in
the coming weeks.
“DART’s success provides a significant
addition to the essential toolbox we must have to protect Earth from a
devastating impact by an asteroid,” said Lindley Johnson, NASA’s Planetary
Defense Officer. “This demonstrates we are no longer powerless to prevent this
type of natural disaster. Coupled with enhanced capabilities to accelerate
finding the remaining hazardous asteroid population by our next Planetary
Defense mission, the Near-Earth Object (NEO) Surveyor, a DART successor could
provide what we need to save the day.”
With the asteroid pair within 7 million
miles (11 million kilometers) of Earth, a global team is using dozens of
telescopes stationed around the world and in space to observe the asteroid
system. Over the coming weeks, they will characterize the ejecta produced and
precisely measure Dimorphos’ orbital change to determine how effectively DART
deflected the asteroid. The results will help validate and improve scientific
computer models critical to predicting the effectiveness of this technique as a
reliable method for asteroid deflection.
“This first-of-its-kind mission required
incredible preparation and precision, and the team exceeded expectations on all
counts,” said APL Director Ralph Semmel. “Beyond the truly exciting success of
the technology demonstration, capabilities based on DART could one day be used
to change the course of an asteroid to protect our planet and preserve life on
Earth as we know it.”
Roughly four years from now, the European
Space Agency’s Hera project will conduct detailed surveys of both Dimorphos and
Didymos, with a particular focus on the crater left by DART’s collision and a
precise measurement of Dimorphos’ mass.
Johns Hopkins APL manages the DART mission for NASA's Planetary Defense Coordination Office as a project of the agency's Planetary Missions Program Office.
To see the final images before DART's
impact, visit: https://go.nasa.gov/3Rer1NW
For more information about DART, visit: https://www.nasa.gov/dart
Source: NASA’s
DART Mission Hits Asteroid in First-Ever Planetary Defense Test | NASA
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