Elon Musk, SpaceX founder and Tesla CEO had recently warned that the Earth had “no defence” against giant asteroids.
"Wouldn't worry about this particular one, but a big rock will hit Earth eventually & we currently have no defence," Musk wrote on Twitter, referring to a media report about NASA’s preparations for an asteroid named Apophis after an Egyptian ‘God of Chaos.’
The Metro UK had reported that if Apophis were indeed to hit a city like London, it would “wipe out millions of people and create a crater roughly three miles wide, but our species would probably survive.”
Great name! Wouldn’t worry about this particular one, but a big rock will hit Earth eventually & we currently have no defense. https://t.co/XhY8uoNNax
— Elon Musk (@elonmusk) August 18, 2019
Musk’s viral tweet had evoked some tongue-in-cheek reactions from Netizens.
I have a Dodge Ram with a 5 star safety rating so I'll be fine.
— Dodge Ram Owner (@RamLover69) August 18, 2019
We have SpaceXForce, Machete will take care of that evil rock! pic.twitter.com/8je9oO0QbQ
— Renata Konkoly (@RenataKonkoly) August 18, 2019
It has been done before in only 18 days pic.twitter.com/wTyblmLtkw
— Roy Harris (@PlywoodMirror) August 18, 2019
Jokes apart, here is what NASA actually has to say about the possibility of Apophis living up to its name and causing damage to Earth.
First of all, our planet’s close brush, in cosmic terms, with Apophis is still a decade away.
And NASA is more excited than worried about the event.
“The Apophis close approach in 2029 will be an incredible opportunity for science,” according to Marina Brozović, a radar scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, who works on radar observations of near-Earth objects (NEOs).
“We’ll observe the asteroid with both optical and radar telescopes. With radar observations, we might be able to see surface details that are only a few meters in size,” Brozović said in a statement in April.
Although NASA had once feared that the 340-metre wide space rock was on a path of collision with Earth, subsequent calculations allayed those concerns by showing that Apophis was going to pass within just 19,000 miles of our planet’s surface. That’s “within the distance that some of our spacecraft that orbit Earth,” according to NASA.
The asteroid was first discovered by a team of astronomers at the Kitt Peak National Observatory discovered Apophis in June 2004— but technical and weather issues prevented them from studying it further after just two days.
Luckily, another team rediscovered the asteroid at the Siding Spring Survey in Australia later that year. “The observations caused quite a stir—initial orbital calculations revealed that the asteroid had a 2.7% chance of impacting Earth in 2029. Fortunately, additional observations refined the orbit and completely ruled out that possibility,” according to NASA.
Besides, optical and radar telescopes have tracked Apophis as it continues on its orbit around the Sun, and so its future trajectory is known quite well.
“Current calculations show that Apophis still has a small chance of impacting Earth, less than 1 in 100,000 many decades from now, but future measurements of its position can be expected to rule out any possible impacts,” NASA says.
However, NASA says, it’s rare for an asteroid the size of Apophis to pass by the Earth so close.
“Although scientists have spotted small asteroids, on the order of 5-10 meters, flying by Earth at a similar distance, asteroids the size of Apophis are far fewer in number and so do not pass this close to Earth as often,” it says.
The asteroid was also discussed at NASA’s annual Planetary Defence Conference in April, with scientists and disaster planners simulating an asteroid apocalypse for an emergency response.
“Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs),” Paul Chodas, director of Nasa’s Centre for Near Earth Objects Studies, had said. “
By observing Apophis during its 2029 flyby, we will gain important scientific knowledge that could one day be used for planetary defence,” Chodas had said.