CAPE CANAVERAL (National Times) \u2014 In the first-of-its kind, save-the-world experiment, NASA is about to clobber a small, harmless asteroid millions of miles away.<\/p>\n
A spacecraft named Dart will zero in on the asteroid Monday, intent on slamming it head-on at 14,000 mph (22,500 kph). The impact should be just enough to nudge the asteroid into a slightly tighter orbit around its companion space rock \u2014 demonstrating that if a killer asteroid ever heads our way, we\u2019d stand a fighting chance of diverting it.<\/p>\n
\u201cThis is stuff of science-fiction books and really corny episodes of \u201cStarTrek\u201d from when I was a kid, and now it\u2019s real,\u201d NASA program scientist Tom Statler said Thursday.<\/p>\n
Cameras and telescopes will watch the crash, but it will take days or even weeks to find out if it actually changed the orbit.<\/p>\n
The $325 million planetary defense test began with Dart\u2019s launch last fall.<\/p>\n
ASTEROID TARGET<\/p>\n
The asteroid with the bull\u2019s-eye on it is Dimorphos, about 7 million miles (9.6 million kilometers) from Earth. It is actually the puny sidekick of a 2,500-foot (780-meter) asteroid named Didymos, Greek for twin. Discovered in 1996, Didymos is spinning so fast that scientists believe it flung off material that eventually formed a moonlet. Dimorphos \u2014 roughly 525 feet (160 meters) across \u2014 orbits its parent body at a distance of less than a mile (1.2 kilometers).<\/p>\n
\u201cThis really is about asteroid deflection, not disruption,\u201d said Nancy Chabot, a planetary scientist and mission team leader at Johns Hopkins University\u2019s Applied Physics Laboratory, which is managing the effort. \u201cThis isn\u2019t going to blow up the asteroid. It isn\u2019t going to put it into lots of pieces.\u201d Rather, the impact will dig out a crater tens of yards (meters) in size and hurl some 2 million pounds (1 million kilograms) of rocks and dirt into space.<\/p>\n
NASA insists there\u2019s a zero chance either asteroid will threaten Earth \u2014 now or in the future. That\u2019s why the pair was picked.<\/p>\n
DART, THE IMPACTOR<\/p>\n
The Johns Hopkins lab took a minimalist approach in developing Dart \u2014 short for Double Asteroid Redirection Test \u2014 given that it\u2019s essentially a battering ram and faces sure destruction. It has a single instrument: a camera used for navigating, targeting and chronicling the final action. Believed to be essentially a rubble pile, Dimorphos will emerge as a point of light an hour before impact, looming larger and larger in the camera images beamed back to Earth. Managers are confident Dart won\u2019t smash into the larger Didymos by mistake. The spacecraft\u2019s navigation is designed to distinguish between the two asteroids and, in the final 50 minutes, target the smaller one.<\/p>\n
The size of a small vending machine at 1,260 pounds (570 kilograms), the spacecraft will slam into roughly 11 billion pounds (5 billion kilograms) of asteroid. \u201cSometimes we describe it as running a golf cart into a Great Pyramid,\u201d said Chabot.<\/p>\n
Unless Dart misses \u2014 NASA puts the odds of that happening at less than 10% \u2014 it will be the end of the road for Dart. If it goes screaming past both space rocks, it will encounter them again in a couple years for Take 2.<\/p>\n
SAVING EARTH<\/p>\n
Little Dimorphos completes a lap around big Didymos every 11 hours and 55 minutes. The impact by Dart should shave about 10 minutes off that. Although the strike itself should be immediately apparent, it could take a few weeks or more to verify the moonlet\u2019s tweaked orbit. Cameras on Dart and a mini tagalong satellite will capture the collision up close. Telescopes on all seven continents, along with the Hubble and Webb space telescopes and NASA\u2019s asteroid-hunting Lucy spacecraft, may see a bright flash as Dart smacks Dimorphos and sends streams of rock and dirt cascading into space. The observatories will track the pair of asteroids as they circle the sun, to see if Dart altered Dimorphos\u2019 orbit. In 2024, a European spacecraft named Hera will retrace Dart\u2019s journey to measure the impact results.<\/p>\n
Although the intended nudge should change the moonlet\u2019s position only slightly, that will add up to a major shift over time, according to Chabot. \u201cSo if you were going to do this for planetary defense, you would do it five, 10, 15, 20 years in advance in order for this technique to work,\u201d she said. Even if Dart misses, the experiment still will provide valuable insight, said NASA program executive Andrea Riley. \u201cThis is why we test. We want to do it now rather than when there\u2019s an actual need,\u201d she said.<\/p>\n
ASTEROID MISSIONS GALORE<\/p>\n
Planet Earth is on an asteroid-chasing roll. NASA has close to a pound (450 grams) of rubble collected from asteroid Bennu headed to Earth. The stash should arrive next September. Japan was the first to retrieve asteroid samples, accomplishing the feat twice. China hopes to follow suit with a mission launching in 2025. NASA\u2019s Lucy spacecraft, meanwhile, is headed to asteroids near Jupiter, after launching last year. Another spacecraft, Near-Earth Asteroid Scout, is loaded into NASA\u2019s new moon rocket awaiting liftoff; it will use a solar sail to fly past a space rock that\u2019s less than 60 feet (18 meters) next year.<\/p>\n
In the next few years, NASA also plans to launch a census-taking telescope to identify hard-to-find asteroids that could pose risks. One asteroid mission is grounded while an independent review board weighs its future. NASA\u2019s Psyche spacecraft should have launched this year to a metal-rich asteroid between Mars and Jupiter, but the team couldn\u2019t test the flight software in time.<\/p>\n
HOLLYWOOD\u2019S TAKE<\/p>\n
Hollywood has churned out dozens of killer-space-rock movies over the decades, including 1998\u2032s \u201cArmageddon\u201d which brought Bruce Willis to Cape Canaveral for filming, and last year\u2019s \u201cDon\u2019t Look Up\u201d with Leonardo DiCaprio leading an all-star cast. NASA\u2019s planetary defense officer, Lindley Johnson, figures he\u2019s seen them all since 1979\u2032s \u201cMeteor,\u201d his personal favorite \u201csince Sean Connery played me.\u201d While some of the sci-fi films are more accurate than others, he noted, entertainment always wins out. The good news is that the coast seems clear for the next century, with no known threats.<\/p>\n
Otherwise, \u201cit would be like the movies, right?\u201d said NASA\u2019s science mission chief Thomas Zurbuchen. What\u2019s worrisome, though, are the unknown threats. Fewer than half of the 460-foot (140-meter) objects have been confirmed, with millions of smaller but still-dangerous objects zooming around. \u201cThese threats are real, and what makes this time special, is we can do something about it,\u201d Zurbuchen said. Not by blowing up an asteroid as Willis\u2019 character did \u2014 that would be a last, last-minute resort \u2014 or by begging government leaders to take action as DiCaprio\u2019s character did in vain. If time allows, the best tactic could be to nudge the menacing asteroid out of our way, like Dart. <\/p>\n","protected":false},"excerpt":{"rendered":"
CAPE CANAVERAL (National Times) \u2014 In the first-of-its kind, save-the-world experiment, NASA is about to clobber a small, harmless asteroid millions of miles away. A spacecraft named Dart will zero in on the asteroid Monday, intent on slamming it head-on at 14,000 mph (22,500 kph). The impact should be just enough to nudge the asteroid […]<\/p>\n","protected":false},"author":1,"featured_media":43751,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-43750","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-international","entry"],"yoast_head":"\n