Later this month, NASA’s DART will intentionally crash into Dimorphos, the asteroid moonlet of Didymos.
While the asteroid poses no threat to Earth, this is the world’s first test of the kinetic impact technique, using a spacecraft to deflect an asteroid for planetary defense.
Double Asteroid Redirection Test (DART)
DART is the first-ever mission dedicated to investigating and demonstrating one method of asteroid deflection by changing an asteroid’s motion in space through kinetic impact.
This method will have DART deliberately collide with a target asteroid which poses no threat to Earth, in order to change its speed and path.
DART’s target is the binary, near-Earth asteroid system Didymos, composed of the roughly 780-meter (2,560-foot) -diameter “Didymos” and the smaller, approximately 160-meter (530-foot)-size “Dimorphos,” which orbits Didymos.
DART will impact Dimorphos to change its orbit within the binary system.
DART is also carrying a cubesat that will film the larger spacecraft's impact and beam the footage back to researchers on Earth.
At the time of DART's impact, Didymos will be visible enough to be a good candidate for study and distant enough to be no danger, at approximately 6.8 million miles (11 kilometers) away from Earth.
DART is a test of our ability to achieve a kinetic impact on an asteroid and observe the asteroid’s response.
After DART’s kinetic impact with its target asteroid Dimorphos, an investigation team will measure how much the impact changed the asteroid’s motion in space using telescopes on Earth.
This mission engages the international planetary science community and embraces worldwide cooperation to address the global issue of planetary defense.
DART’s Mission Objectives:
Demonstrate a kinetic impact with Dimorphos.
Change the binary orbital period of Dimorphos.
Use ground-based telescope observations to measure Dimorphos’ period change before and after impact.
Measure the effects of the impact and resulting ejecta on Dimorphos.
What is an Asteroid?
Asteroids are small, airless rocky worlds revolving around the sun that are too small to be called planets.
They are also known as planetoids or minor planets.
In total, the mass of all the asteroids is less than that of Earth’s moon. But despite their size, asteroids can be dangerous.
Many have hit Earth in the past, and more will crash into our planet in the future.
Where asteroids are located?
Most asteroids lie in a vast ring between the orbits of Mars and Jupiter.
Not everything in the main belt is an asteroid, for instance, comets have recently been discovered there, and Ceres, once thought of only as an asteroid, is now also considered a dwarf planet.
Many asteroids lie outside the main belt. For instance, a number of asteroids called Trojans lie along Jupiter’s orbital path.
Three groups — Atens, Amors, and Apollos — known as near-Earth asteroids orbit in the inner solar system and sometimes cross the path of Mars and Earth.