NASA says DART spacecraft successfully redirected asteroid’s path
NASA says it has successfully barter an asteroid, in a historic test of humanity’s ability to stop an incoming cosmic object from destroying life on Earth.
The refrigerator-sized Double Asteroid Redirection Test (DART) impactor deliberately crashed into asteroid Dimorphos on September 26.pushing it into a smaller, faster orbit around its big brother Didymos, NASA Administrator Bill Nelson said.
DART shortened an 11-hour, 55-minute orbit to 11 hours, 23 minutes, he said. Speeding up Dimorphos orbital period by 32 minutes, beating NASA’s own expectations by 10 minutes.
We showed the world that NASA is serious about being a defender of the planet, Nelson said.
The pair of asteroids, which orbit the sun together every 2.1 years, pose no threat to Earth, but they present an ideal test for the kinetic shock approach to planetary defenses in case an object actually approaching is detected.
Harvard University astronomer Yvette Cendes told Al Jazeera: There is no risk in this case because it was a purposely chosen goal to make sure that this doesn’t happen.
The success of DART as a proof of idea made science fiction a reality.
Astronomers are delighted with stunning images of material spreading thousands of kilometers after the impact. The pictures were collected by Earth and space telescopes and a satellite carrying DART to the region.
I grew up watching Armageddon and Deep Impact and all of that, and it was amazing to see that stuff come to life, Cendes said.
Thanks to its temporary new tail, Dimorphos, which is 160 meters (530 feet) in diameter or roughly the size of the Great Pyramid of Egypt, has been transformed into a man-made comet.
But quantifying the test’s effects requires an analysis of light patterns from ground-based telescopes, which will take several weeks to become apparent.
The binary asteroid system was about 11 million kilometers (6.8 million miles) from Earth at the time of the impact, visible only as a single point from the ground.
garbage dump’
Ahead of the test, NASA scientists said the results will reveal whether the asteroid is a solid rock or more of a “junk heap” of boulders bound by mutual gravitational pull.
If the asteroid is stronger, the momentum provided by the spacecraft will be limited. But if it’s fluffy and a lot of mass is pushed at high speeds in the opposite direction of the impact, there’s an extra boost.
Never actually photographed before, Dimorphos appeared as a point of light about an hour before impact.
Its egg-like shape and rugged, boulder-strewn surface finally became visible in the final minutes as DART sprinted towards it at around 23,500 km/h (14,500 mph).
Of the billions of asteroids and comets in our solar system, only a handful are considered potentially hazardous to our planet, and none are expected to impact for the next 100 years or so. For example, geological records show that a 9.6-kilometer (6-mile)-wide asteroid hit Earth 66 million years ago, plunging the world into a long winter that wiped out the dinosaurs and 75 percent of all species.
In contrast, Dimorphos-sized asteroids would only have a regional impact, such as destroying a city.
Kinetic ramming of a spacecraft is just one way to defend Earth, even though it’s the only way feasible with current technology.
If an approaching object is detected early, a spacecraft can be sent to fly alongside it long enough to use the spacecraft’s gravity to alter its path, creating what’s known as a gravity tractor.
Another option is to launch a nuclear explosive to redirect or destroy the asteroid.
NASA believes the best way to deploy such a weapon is at a distance to exert force without blowing the asteroid to pieces, which could further endanger Earth.
China slams NASA over claims it could take over the moon
China has criticized the NASA chief’s warning that Beijing could use the moon as part of its military space program.
Chinese Foreign Ministry spokesman Zhao Lijian told reporters on Monday that China firmly opposed the irresponsible remarks made by NASA Administrator Bill Nelson.
NASA Administrator Nelson told German newspaper Bild in an interview published on Saturday that he was concerned about China’s space ambitions.
We have to be very worried that China is going to the moon and saying .It’s ours now, you don’t come in, he said, referring to Beijing’s lunar exploration program.
China, which has stepped up its space program over the past decade, has made exploring the moon a priority.
It conducted its first unmanned lunar landing in 2013 and plans to conduct an uncrewed mission to the lunar south pole sometime this decade.
It also plans to launch a rocket powerful enough to put astronauts on the moon by the end of the decade, and has its sights set on