At first glance, the mission, called Double Asteroid Redirection Inspection, or DART, might sound a little silly (sorry, NASA). Like a billiard cue that hits an asteroid with an eight-ball that looks like what Nathan Field might suggest in an episode of “Nathan For You.” You can almost imagine this comic calmly pitching to a staff of NASA engineers: “The plan? Save Earth from a harmful asteroid by colliding with a $1,000,000 spacecraft. ,
However, NASA has high hopes for the mission. If profitable, it could change the way we fund and develop planetary conservation missions.
Asteroids are notorious sticky crickets. On the one hand, they are relics from the beginning of our photovoltaic systems; relics from the very beginning – or whatever our work was. Or, the asteroid has done unimaginable damage to our planet. About 66 million years ago, a 6-mile-wide asteroid collided off the coast of what is now Mexico’s Yucatan Peninsula. An asteroid gives us the chance to see pterosaurs soar through the sky, or eat with them, depending on which way you look at it.
Dart can’t undo the damage from previous asteroid strikes, but it may help us stop them sooner or later. Through dart collisions, scientists have investigated a planetary protection technique, commonly referred to as “kinetic impactor expertise,” whose goal is to manipulate — rather than destroy — an object.
In Dart’s case, the target was Dimorphos, a rock orbiting each other, and a larger asteroid known as Didymos. (In astronomical terms, this makes Dimorphos “moonlight.”) If all goes according to plan, Dart will push Dimorphos closer to its guardian asteroid, orbiting Didymos for 11.9 to 11.8 hours. Modified the time taken – a small but significant change.
Fortunately, Didymos and Dimorphos pose no threat to Earth, so no matter what happens on Monday, humanity is temporarily protected. However, as near-Earth asteroids, Didymos and Dimorphos belong to a class of rocks that we need to consider additionally. According to NASA’s Center for Near-Earth Object Research, about 29,000 such objects have been discovered. Of that number, several thousand are considered “possibly harmful,” but precise numbers are hard to find.
While the chances of a giant asteroid actually hitting Earth may be very small, when near-Earth objects (asteroids and comets in general) enter our environment, the results can be catastrophic. In 1908, an asteroid or comet traveling at about 33,500 mph exploded 3 to 6 miles above the Tunguska River in Podkamena, Siberia. The exact details about that event, known as the Tunguska influence, are still shrouded in the thriller. However, the life force released by the explosion leveled the entire forest, killing a wide variety of wood and animals. It is estimated that the driving force of the explosion could be as high as 15 megatons of TNT.
History repeated itself in 2013 — albeit to a much lesser degree, fortunately — when the 65-foot asteroid exploded over Chelyabinsk, Russia, about 14 miles before reaching land, producing a giant gas and Mud cloud. The ensuing earthquake damaged 7,200 buildings in six cities and injured 1,500 people.
What makes asteroids and such occasions so terrifying is that they are completely out of our control. The idea of objects randomly hitting the Earth and causing a lot of damage is hard to come by.
It’s true that we can’t manipulate the trajectory of every NEO, but we can determine and monitor their orbits in higher elements earlier than ever before. Furthermore, investing in planetary protection missions like DART brings us one step closer to stopping the one thing that cannot be stopped at any time.
“Planet Safety” sounds like something out of a regional thriller, like Michael Bay’s 1998 blockbuster “Doomsday.” However, this is not science fiction. In fact, my Planetary Society has made the defense of Earth one of the many core tenets of our mission. We try to guide the public on missions like DART, entice Congress to fund planetary conservation, and fund novice astronomers working to capture NEOs.
Deflecting an asteroid is a daring endeavor — even impractical. Yet so is saving the world. Each is worth the effort.