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| Photo Credit: AP. |
CAPE CANAVERAL, Fla. (AP) — A NASA spacecraft closed in on an asteroid at blistering speed Monday in an unprecedented dress rehearsal for the day a killer rock menaces Earth.
The galactic
grand slam was set to occur at a harmless asteroid 7 million miles (9.6 million
kilometers) away, with the spacecraft named Dart plowing into the rock at
14,000 mph (22,500 kph). Scientists expected the impact to carve out a crater,
hurl streams of rocks and dirt into space and, most importantly, alter the
asteroid’s orbit.
Telescopes
around the world and in space were poised to capture the spectacle. Though the
impact should be immediately obvious — with Dart’s radio signal abruptly
ceasing — it will be days or even weeks to determine how much the asteroid’s
path was changed.
The $325
million mission is the first attempt to shift the position of an asteroid or
any other natural object in space.
“No, this is not a movie plot,” NASA
Administrator Bill Nelson tweeted earlier in the day. ”We’ve all seen it on
movies like ‘Armageddon,’ but the real-life stakes are high,” he said in a
prerecorded video.
Monday’s
target: a 525-foot (160-meter) asteroid named Dimorphos. It’s actually a
moonlet of Didymos, Greek for twin, a fast-spinning asteroid five times bigger
that flung off the material that formed the junior partner.
The pair
have been orbiting the sun for eons without threatening Earth, making them
ideal save-the-world test candidates.
Launched
last November, the vending machine-size Dart — short for Double Asteroid
Redirection Test — navigated to its target using new technology developed by
Johns Hopkins University’s Applied Physics Laboratory, the spacecraft builder
and mission manager.
A mini
satellite followed a few minutes behind to take photos of the impact. The
Italian Cubesat was released from Dart two weeks ago.
Scientists
insisted Dart would not shatter Dimorphos. The spacecraft packed a scant 1,260
pounds (570 kilograms), compared with the asteroid’s 11 billion pounds (5
billion kilograms). But that should be plenty to shrink its 11-hour, 55-minute
orbit around Didymos.
The impact
should pare 10 minutes off that, but telescopes will need anywhere from a few
days to nearly a month to verify the new orbit. The anticipated orbital shift
of 1% might not sound like much, scientists noted. But they stressed it would
amount to a significant change over years.
Planetary
defense experts prefer nudging a threatening asteroid or comet out of the way,
given enough lead time, rather than blowing it up and creating multiple pieces
that could rain down on Earth. Multiple impactors might be needed for big space
rocks or a combination of impactors and so-called gravity tractors,
not-yet-invented devices that would use their own gravity to pull an asteroid
into a safer orbit.
“The
dinosaurs didn’t have a space program to help them know what was coming, but we
do,” NASA’s senior climate adviser Katherine Calvin said, referring to the mass
extinction 66 million years ago believed to have been caused by a major
asteroid impact, volcanic eruptions or both.
The
non-profit B612 Foundation, dedicated to protecting Earth from asteroid
strikes, has been pushing for impact tests like Dart since its founding by
astronauts and physicists 20 years ago. Monday’s dramatic action aside, the
world must do a better job of identifying the countless space rocks lurking out
there, warned the foundation’s executive director, Ed Lu, a former astronaut.
Significantly
less than half of the estimated 25,000 near-Earth objects in the deadly
460-foot (140-meter) range have been discovered, according to NASA. And fewer
than 1% of the millions of smaller asteroids, capable of widespread injuries,
are known.
The Vera
Rubin Observatory, nearing completion in Chile by the National Science
Foundation and U.S. Energy Department, promises to revolutionize the field of
asteroid discovery, Lu noted.
Finding and
tracking asteroids, “That’s still the name of the game here. That’s the thing
that has to happen in order to protect the Earth,” he said.
The
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