A group of astronomers has calculated that the Earth’s gravitational pull could affect the surface of the asteroid Apophis, which will come close to our planet in April 2029. It is now at a distance of about 1.97 astronomical units from Earth. But in five years the asteroid will pass at a distance of 32,000 kilometers, which is almost 10 times closer than the distance of the Earth to the Moon. The researchers suggest that gravitational interaction with Earth will cause seismic landslides and earthquake-like surface changes on Apophis, which could even be detected by seismometers. True, these changes on the asteroid will not occur immediately, but gradually, over tens of thousands of years.
The results of the study have already been posted on the arXiv preprint server and will soon be published in The Planetary Science Journal.
This effect, similar to the one affecting the surface of moons of planets such as Miranda near Uranus, is of considerable interest to science. Unlike large celestial bodies such as the Moon, Apophis is much smaller, so Earth’s gravitational impact will be even more intense. The researchers believe this interaction could also change the asteroid’s rotation rate, causing long-term surface changes. This opens up opportunities to study the structures and processes that form the internal structure of asteroids.
Since Apophis’ approach is extremely rare, space agencies such as NASA plan to study it at close range. NASA’s OSIRIS-APEX mission aims to study how the asteroid’s surface reacts to the impact of Earth’s gravity.
Apophis was discovered in 2004, and named after the ‘God of chaos’ Apep, the eternal enemy of the God of the Sun Ra in ancient Egyptian mythology. Astronomers have calculated that it could fly very close to Earth in 2029. More detailed observations in 2021 allowed scientists to determine Apophis’ path with greater accuracy, finding that it had a lower chance of hitting Earth than researchers originally estimated. Apophis is now expected to approach Earth at a distance of 32,000 kilometers on April 13, 2029, which would bring it closer than some artificial satellites.
Although the probability of Apophis colliding with Earth is extremely low, calculations show that such objects can cause significant damage. Asteroids the size of Apophis collide with Earth about once every 80,000 years, causing great regional disruption and possible climate change. For example, in 2013, an asteroid with a diameter of 20 metres flew over Cheliabinsk, releasing energy equivalent to 500 kilotons of TNT and causing a powerful shock wave.
Despite the small risk, NASA is keeping a close eye on objects like Apophis, because their proximity to Earth can pose a danger.
Earlier we reported on how ESA would send a mission to an Earth-threatening asteroid.
Provided by livescience.com
