EARTH could collide with its deadly cosmic neighbour, Apophis, an asteroid 1,100ft (335m) wide, should a rare chain event occur, according to a new study.
Though it would be a one in a billion chance.
Researchers at ESA announced in July that they are sending out their Ramses mission spacecraft in 2028 to keep an eye on Apophis[/caption]
The near-Earth object (NEO), which is larger than the Eiffel Tower, is scheduled to make an intimidatingly close flyby of Earth on Friday 13, 2029.
It is expected to pass around 19,800 miles (32,000km) of Earth, closer than some satellites, where some stargazers may be able to see it with the naked eye.
No asteroid is expected to come as close for a few thousand years.
New research has suggested that if Apophis, dubbed the “God of Destruction”, is hit by other space rocks in its journey around the solar system, it’s path may be diverted to collide with Earth.
However, the chances of such a chain event is very low, research author Paul Wiegert, an astronomer at the University of Western Ontario, told Space.com.
“The odds are essentially 1 in a million that an asteroid strike could deflect Apophis enough to put it in danger of a future post-2029 collision, and only 1 in a billion that it could send Apophis colliding with Earth in 2029,” he explained.
Earth's closest near-misses
One of Earth's closest near-misses occurred only a few years ago.
Asteroid VT4, which is estimated to be just five to 10 metres in diameter, came as close as 383 km to the Earth’s surface in 2020.
Another close encounter happened on 31 March 2004, when meteoroid FU162 zoomed past just 6500km above Earth’s surface.
But as experts at the Royal Greenwich Observatory explain, both these asteroids would have been relatively harmless.
“FU162 is only 10m across, so if it had collided with the Earth it would almost certainly have exploded harmlessly in the upper atmosphere,” experts said.
Then in May 1996, asteroid JA1 passed the Earth 450,000km away – which is about as far away as the Moon.
Wiegert added: “I calculated the odds of asteroid Apophis, whose current path is computed to take it near but safely past our planet in 2029, being deflected onto a more dangerous path by an unexpected small asteroid impact.
“These are the same kind of small asteroids that occasionally appear in our atmosphere as ‘shooting stars’ or ‘fireballs’ and could strike Apophis just as unexpectedly.”
Wiegert noted that an asteroid roughly 60cm (24inches), if it hit Apophis, could push the giant space rock onto a future collision course with Earth, sometime after 2029.
But a second, larger, 3m (10ft) asteroid strike with Apophis could “put in danger of a collision in 2029,” said Wiegart.
“These kinds of collisions are extremely rare,” he concluded.
Ramses needs to launch in April 2028 in order to reach Apophis in February 2029[/caption]
Eyes in the sky
Apophis, named after the Egyptian serpent god of chaos and destruction Apep, was discovered in 2004 and sat atop the European Space Agency’s (ESA’s) “impact risk list” and NASA’s Sentry Risk Table for nearly two decades.
But a close flyby of the asteroid in March 2021 showed Nasa scientists that Apophis won’t actually hit Earth for at least 100 years.
Researchers at ESA announced in July that they are sending out their Ramses mission spacecraft in 2028 to keep an eye on it.
The ESA are doubling down on efforts to secure Earth’s defences against future, potentially cataclysmic, space rocks, following the success of Nasa’s DART mission in 2022.
In 2023, Nasa rebranded its OSIRIS-REx spacecraft to study the asteroid instead of being retired.
Now going by OSIRIS-APEX (Origins, Spectral Interpretation, Resource Identification, and Security – Apophis Explorer), the craft successfully returned samples from the space rock Bennu.
Its second mission will investigate Apophis before, during, and after its close pass.
Scientists, at both ESA and Nasa, are keen to know how the giant space rock is influenced by Earth’s gravity during such a close flyby.
What's the difference between an asteroid, meteor and comet?
Here's what you need to know, according to Nasa…
- Asteroid: An asteroid is a small rocky body that orbits the Sun. Most are found in the asteroid belt (between Mars and Jupiter) but they can be found anywhere (including in a path that can impact Earth)
- Meteoroid: When two asteroids hit each other, the small chunks that break off are called meteoroids
- Meteor: If a meteoroid enters the Earth’s atmosphere, it begins to vapourise and then becomes a meteor. On Earth, it’ll look like a streak of light in the sky, because the rock is burning up
- Meteorite: If a meteoroid doesn’t vapourise completely and survives the trip through Earth’s atmosphere, it can land on the Earth. At that point, it becomes a meteorite
- Comet: Like asteroids, a comet orbits the Sun. However rather than being made mostly of rock, a comet contains lots of ice and gas, which can result in amazing tails forming behind them (thanks to the ice and dust vaporizing)
