NASA’s new asteroid-sampling goal will do a lot of engaging things, though assisting ready amiability for Earth’s approaching destruction is not among them.
There is indeed a possibility that a 1,650-foot-wide (500 meters) asteroid Bennu — the aim of NASA’s OSIRIS-REx spacecraft, that is scheduled to launch subsequent month — could strike Earth late in a 22nd century.
But, goal officials stressed, that possibility is slim, and a space stone is not scarcely large adequate to poise an existential hazard to a planet, notwithstanding what some media reports claimed over a weekend. [Potentially Dangerous Asteroids (Images)]
“We’re not articulate about an asteroid that could destroy a Earth,” OSIRIS-REx principal questioner Dante Lauretta, of a Lunar and Planetary Laboratory during a University of Arizona, told Space.com. “We’re not anywhere nearby that kind of appetite for an impact.”
Sampling an asteroid
If all goes according to plan, a $800 million OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) goal will lift off atop a United Launch Alliance Atlas V rocket from Florida’s Cape Canaveral Air Force Station on Sept. 8.
The booster will spend dual years chasing Bennu down, finally rendezvousing with a near-Earth asteroid in Aug 2018. OSIRIS-REx will afterwards examine a space stone from circuit for another dual years before grabbing during slightest 2.1 ounces (60 grams) of aspect element in Jul 2020.
In 2023, this comparatively large representation should make it behind to Earth, where researchers in laboratories around a creation will examine a element in a series of ways.
The goal group is customarily meddlesome in training a purpose that asteroids like Bennu — dark, obsolete and apparently carbon-rich objects — might have played in assisting life get a foothold on Earth, Lauretta said.
“Did these kinds of bodies broach organic element and water, in a form of hydrated minerals like clays, to a aspect of a world that combined a habitability and a environments that might have led to a start of life?” Lauretta said.
“That’s a primary mission,” to examine that question, he added.
There are delegate objectives as well, including training some-more about a profitable resources that Bennu-like asteroids might harbor, Lauretta said. And afterwards there’s a planetary-defense angle, that has gotten a lot of attention in a final few days.
A potentially dangerous asteroid
Bennu is strictly personal as a potentially dangerous asteroid. In fact, there’s an 0.037 percent (or 1-in-2,700) possibility that it will strike Earth in a final entertain of a 22nd century, NASA scientists have calculated.
Specifically, that’s a luck that, during an Earthy flyby in 2135, Bennu will strike a special orbit-altering “keyhole” that will send it on a collision march with a world after in a century.
OSIRIS-REx will assistance scientists labour those odds, by enlightening their bargain of Bennu’s orbit. (That orbit, by a way, is already a best-known of any asteroid, Lauretta said; interjection to endless observations given Bennu’s 1999 discovery, astronomers have nailed a space rock’s orbital radius down to within 20 feet, or 6 m.)
“Our uncertainties will shrink, so that will concede us to recalculate a impact probability,” Lauretta said. “We don’t know that instruction it’ll go. It could go down, since we usually separated a garland of probable keyholes that Bennu might hit. Or it might go up, since in a area that’s left we have a aloft thoroughness of keyholes compared to a altogether area of a doubt plane.”
OSIRIS-REx’s work will also assistance researchers improved know a Yarkovsky effect, that describes how engrossed sunlight, when radiated divided as heat, affects an object’s trajectory. Such information will urge believe not usually of where Bennu is headed, though where it came from, Lauretta said.
But to concentration on where it’s headed — what if Bennu does strike one of those keyholes in 2135, and a space stone squares Earth adult for an impact in 2185 or thereabouts? What should amiability expect?
Such an impact would expected fleece a internal area though tumble brief of wiping out civilization or causing a mass extinction, experts have said. Astronomers guess that a space stone contingency be during slightest 0.6 miles (1 kilometer) far-reaching to means a tellurian catastrophe. (For perspective: The asteroid suspicion to have wiped out a dinosaurs — or during slightest to have finished them off — was substantially about 6 miles, or 10 km, across.)
But an impact would not be inevitable, even if Bennu had Earth in a sights. Given a decade or so value of lead time, researchers say, an incoming asteroid could potentially be nudged off course regulating fly-along “gravity tractor” probes and/or “kinetic impactors.” And if time is not on humanity’s side, there’s always a nuclear option.