NASA plans to launch a spacecraft next month to visit an incoming asteroid that has a chance of striking Earth in the late 22nd century, but even if its does strike the planet, civilization won’t end.
The OSIRIS-REx spacecraft will spend the next two years chasing down the asteroid known as Bennu before it rendezvouses with the space rock in 2018, collects surface samples in 2020 and returns to Earth in 2023.
NASA classifies the asteroid Bennu as a dangerous asteroid, but it’s not a planet killer. The space agency gives the 1,650 foot wide asteroid a 1-in-2,700 chance of striking Earth, but even if it does civilization won’t end, principal investigator Dante Lauretta told Space.com
“We’re not talking about an asteroid that could destroy the Earth. We’re not anywhere near that kind of energy for an impact.”
The danger will come in 2135 when Bennu does a near Earth flyby; the asteroid has the possibility of hitting an orbit altering “keyhole” that could send it on a collision course with the planet later in the century.
That’s one of the reasons NASA has chosen to send the $800 million Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft out to meet the asteroid.
The mission will help NASA scientists better understand the asteroid’s orbit. Lauretta told Scientific American.
“Our uncertainties will shrink, so that will allow us to recalculate the impact probability. We don’t know which direction it’ll go.”
The OSIRIS-Rex will launch from Florida’s Cape Canaveral Station Sept. 8 atop an Atlas V rocket and spend the next two years flying out to meet Bennu. In August, 2018, the spacecraft will reach the space rock, and it will spend the next two years studying in orbit around the space rock before grabbing a 2.1 ounce surface sample in July 2020.
When the OSIRIS-REx spacecraft returns to Earth in 2023, NASA researchers will study the sample, which they hope will help them better understand the role asteroids played in helping life develop on Earth, Lauretta told Scientific American.
“Did these kinds of bodies deliver organic material and water, in the form of hydrated minerals like clays, to the surface of our planet that created the habitability and the environments that may have led to the origin of life?”
The mission’s secondary objectives include learning more about the possibility of mining valuable resources that could be in asteroids circling the Earth. The scientific data gathered by OSIRIS-REx will also help NASA scientists recalculate the asteroids impact probability; but even if the Bennu does strike Earth, it won’t end civilization.
Astronomers say space rocks must be at least six miles wide to cause serious damage; for comparison, the asteroid the killed the dinosaurs was about six miles wide, while Bennu is a mere 1,600 feet wide.
Even if the asteroid is heading for Earth, an impact isn’t certain; with a decade to prepare, NASA could always nudge the asteroid off course with “gravity tractor” probes or “kinetic impactors.”
There’s also the possibility of firing off a nuclear missile to stop the asteroid from striking Earth. Russia is working on such a planetary defense system now, and they’re equipping former Cold War era ballistic missiles with the capability to shoot down potentially killer asteroids.
It’s space rocks like this that prompted a group of concerned scientists to start Asteroid Day, an international awareness movement educating people around the globe about the dangers of falling space rocks and what we can do to protect ourselves.
Asteroid Day is celebrated June, 30 to commemorate the largest asteroid impact in Earth’s history, besides the one that killed the dinosaurs, when a huge space rock struck Siberia in 1908.
[Photo credit: NASA YouTube video screenshot]