2023-12-28 13:41:27
A NASA spacecraft, recently returned from a mission to the asteroid Bennu, has been relaunched to study its colleague Apophis, named after the Egyptian god of Chaos, as the latter approaches Earth’s orbit. The rocky body should pass, on April 13, 2029, less than 32,000 kilometers from the surface of the globe.
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His name is not the most reassuring. As the asteroid named Apophis, named after the Egyptian god of Chaos, approaches Earth’s orbit, a NASA spacecraft, recently returned from space, was relaunched for a mission to study this rock approximately 370 meters in diameter, announced Friday December 22 the American space agency.
The appointment is set for April 13, 2029. There is therefore a little more than five years before the rocky body of approximately 40 to 50 million tons approaches the blue planet, at a distance less than that which separates us from certain artificial satellites. An extremely close flyby which, as NASA reminds us, has never happened in history since humanity has been able to observe and record this type of astronomical phenomena.
If in Egyptian mythology, Apophis, god in the form of a serpent and incarnation of darkness and the end of the world, seeks to annihilate divine creation, the asteroid that bears his name does not, however, have the same plan for the Earth. But its passage, expected less than 32,000 kilometers from the surface of the globe could make it visible to the naked eye in the eastern hemisphere (covering the Asian continent, the Indian Ocean, Australia, most of the African continent and the European continent, part of the Pacific Ocean and Antarctica).
Explain the before, anticipate the after
After a journey of seven years and 4 billion kilometers, the OSIRIS-REx spacecraft – which brought back a sample of the asteroid Bennu last September – still had fuel and thus set off again on a mission to Apophis. Cost of extending the mission: 200 billion dollars.
Several other destinations had been considered, like Venus, but Apophis was chosen. An “S” type asteroid, composed of silicate materials and nickel-iron, which is distinguished from “C” type asteroids, rich in carbon like Bennu. The spacecraft was renamed OSIRIS-APEX (Origins, Spectral Interpretation, Resource Identification, and Security – Apophis Explorer) for the occasion.
On April 13, 2029, Apophis will skirt the Earth and will then be permanently accompanied by the vessel which will approach up to 25 meters from its surface to extract as much information as possible, in order to study in particular “how the surface is changing by interacting with Earth’s gravity,” announced Amy Simon, mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
As NASA explains, “Apophis’ close encounter with Earth will change the asteroid’s orbit and the length of its day by 30.6 hours.” This encounter could then cause earthquakes and landslides on the surface of the asteroid, which in this case will allow material to be stirred up.
“We know that tidal forces and debris accumulation are fundamental processes that could play a role in planet formation,” says Dani Mendoza DellaGiustina, principal investigator of the OSIRIS-APEX mission at the University of Tucson, Arizona. “They could shed light on how we went from the debris of the early solar system to full-fledged planets.”
While most known potentially hazardous asteroids (with orbits within 4.6 million kilometers of Earth) are also “S” type, exploration of Apophis could contribute to research in matter of planetary defense, absolute priority for NASA.
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The hypothesis of a collision with the Earth ruled out
The discovery – in 2004 at the Kitt Peak Observatory (Arizona) – of the gigantic “God of Chaos” aerolite, initially aroused concern, and still today fuels some theories scattered here and there on the social networks regarding an alleged collision with the Earth. “Apophis is coming, that’s why they are building their bunkers”, we can read in particular from a user of X (ex-Twitter).
In the early stages of its study, the asteroid was classified at level 4 on the Turin scale (used to categorize from 0 to 10 the risks of impacts from near-Earth objects, such as asteroids or comets), which which made it a unique case.
But in December 2004, just a few months after the discovery of the asteroid, the scientific community demonstrated that it was ultimately very unlikely that it would come to play spoilsport.
Even more, in June 2021, the passage of Apophis just 17 million kilometers from Earth made it possible to definitively rule out the hypothesis of a collision, NASA ensuring that its orbit made it possible to exclude with certainty any impact for at least the next hundred years at least.
Sweeping away a way denouement “Don’t Look Up”NASA’s Center for the Study of Near-Earth Objects even officially removed Apophis from the list celestial bodies at risk.
After the asteroid passes near Earth, OSIRIS-APEX will operate near it for the following 18 months to study in particular the changes caused to Apophis by its proximity to Earth.
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