‘A new era’: NASA strikes asteroid in key test of planetary defense

This file artist's illustration obtained from NASA on November 4, 2021 shows the DART spacecraft from behind prior to impact at the Didymos binary system. (AFP)
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Updated 27 September 2022
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‘A new era’: NASA strikes asteroid in key test of planetary defense

  • DART’s celestial target is an asteroid “moonlet” about 560 feet (170 meters) in diameter that orbits a parent asteroid five times larger called Didymos as part of a binary pair with the same name, the Greek word for twin

CAPE CANAVERAL, Florida: A NASA spaceship on Monday struck an asteroid seven million miles away in order to deflect its orbit, succeeding in a historic test of humanity’s ability to prevent a celestial object from devastating life on Earth.

The Double Asteroid Redirection Test (DART) impactor hit its target, the space rock Dimorphos, at 7:14 p.m. Eastern Time (2314 GMT), 10 months after blasting off from California on its pioneering mission.

“We’re embarking on a new era, an era in which we potentially have the capability to protect ourselves from something like a dangerous hazardous asteroid impact,” said Lori Glaze, director of NASA’s planetary science division.

Dimorphos — a 530-foot (160-meter) asteroid roughly comparable in size to an Egyptian pyramid — orbits a half-mile long big brother called Didymos. Never seen before, the “moonlet” appeared as a speck of light around an hour before the collision.

Its egg-like shape and craggy, boulder-dotted surface finally came into clear view in the last few minutes, as DART raced toward it at roughly 14,500 miles (23,500 kilometers) per hour.

NASA scientists and engineers erupted in applause as the screen froze on a final image, indicating that signal had been lost and impact had taken place.

To be sure, the pair of asteroids pose no threat to our planet as they loop the Sun every two of our years.

But NASA has deemed the experiment important to carry out before an actual need is discovered.

By striking Dimorphos head on, NASA hopes to push it into a smaller orbit, shaving 10 minutes off the time it takes to encircle Didymos, which is currently 11 hours and 55 minutes.

Ground telescopes — which can’t see the asteroid system directly but can detect a shift in patterns of light coming from it — should provide a definitive orbital period in the coming days and weeks.

The proof-of-concept has made a reality of what has before only been attempted in science fiction — notably in films such as “Armageddon” and “Don’t Look Up.”

Minutes after impact, a toaster-sized satellite called LICIACube, which already separated from DART a few weeks ago, was expected to make a close pass of the site to capture images of the collision and the ejecta — the pulverized rock thrown off by the strike.

LICIACube’s pictures will be sent back in the next weeks and months.

Also watching the event: an array of telescopes, both on Earth and in space — including the recently operational James Webb — which might be able to see a brightening cloud of dust.

The mission has set the global astronomy community abuzz, with more than three dozen ground telescopes participating, including optical, radio and radar.

“There’s a lot of them, and it’s incredibly exciting to have lost count,” said DART mission planetary astronomer Christina Thomas.

Finally, a full picture of what the system looks like will be revealed when a European Space Agency mission four years down the line called Hera arrives to survey Dimorphos’ surface and measure its mass, which scientists can currently only guess at.

Very few of the billions of asteroids and comets in our solar system are considered potentially hazardous to our planet, and none are expected in the next hundred years or so.

But wait long enough, and it will happen.

We know that from the geological record — for example, the six-mile wide Chicxulub asteroid struck Earth 66 million years ago, plunging the world into a long winter that led to the mass extinction of the dinosaurs along with 75 percent of all species.

An asteroid the size of Dimorphos, by contrast, would only cause a regional impact, such as devastating a city, albeit with greater force than any nuclear bomb in history.

How much momentum DART imparts on Dimorphos will depend on whether the asteroid is solid rock, or more like a “rubbish pile” of boulders bound by mutual gravity — a property that’s not yet known.

If it had missed, NASA would have another shot in two years’ time, with the spaceship containing just enough fuel for another pass.

But its success marks the first step toward a world capable of defending itself from a future existential threat.

“I think Earthlings can sleep better, definitely I will,” said DART mission systems engineer Elena Adams.


Thai officials say 72 tigers at tourist parks died of canine distemper, allaying bird flu fears

Updated 9 sec ago
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Thai officials say 72 tigers at tourist parks died of canine distemper, allaying bird flu fears

  • “There has not been an animal-to-human infection case,” Promphat said
  • “If we detect any sick persons, we will prepare for a nationwide monitoring measure,” said Khanasawat

BANGKOK: The deaths of 72 tigers in two animal parks for tourists in northern Thailand shouldn’t be a major concern for the public, officials said Tuesday, because they were caused by a virus not known to affect humans, rather than bird flu.
No one has shown any symptoms so far, but authorities were nonetheless monitoring the health of people who had recently come into contact with the animals.
“There has not been an animal-to-human infection case,” Public Health Minister Pattana Promphat said at a news conference at Government House in Bangkok.
The tigers in the parks in Mae Taeng and Mae Rim districts in Chiang Mai province became sick and died during a roughly 10-day period between Feb. 8-18.
On Friday, the Chiang Mai regional livestock office announced in a statement that autopsies of the animals found genetic material of canine distemper virus, or CDV, and traces of bacterial infection, but no avian influenza type A virus, also known as bird flu.
“If we detect any sick persons, we will prepare for a nationwide monitoring measure,” said Monthien Khanasawat, director-general of the Public Health Ministry’s Disease Control Department. “This will include contact tracing and treatment as necessary.”
Monthien spoke at the news conference in an apparent effort to reassure the public that the tigers’ deaths didn’t come from bird flu, which has been resurgent in parts of Asia. Thailand saw 17 deaths among 25 infected patients from poultry-caused influenza from 2004 to 2007, according to the Public Health Ministry.
CDV, infectious for both dogs and felines, can cause stronger symptoms in cats and tigers and can be spread through bodily fluids and air. Thai authorities said that tigers in confined environments, and which are already affected by stress and inbreeding conditions, could be particularly vulnerable to the viral infection.
The remains of the tigers went through necropsies before being cremated and buried. The carcasses were properly disinfected, photographed and discarded to prevent any further use, Livestock Development Department Director-General Somchuan Rattanamangklanan said at the news conference.
But Visit Arsaithamkul, a veterinarian who took part in the tiger necropsies, expressed concern that the origins of the infections remained unclear without further investigation. In a Facebook post, he said that he suspected that as the two parks were located just 30 kilometers (18 miles) apart, the cause of infection could be food the tigers were fed that came from the same source.
He declined to elaborate when contacted by The Associated Press. Both parks, run under the name of Tiger Kingdom, remain closed. The operators didn’t immediately respond when asked for comment.
Thai authorities are still alert for the threat of a bird flu outbreak. Monthien, the Public Health Ministry director, urged Thais to be careful with their consumption of poultry after a man in a neighboring country that he didn’t name was found infected with bird flu.
The first animal-to-human transmission of bird flu was discovered in Hong Kong in 1997 before a pandemic started spreading in Asia in 2003. In Thailand, tens of millions of poultry were exterminated and consumption plunged in fear of getting infected.