In Egyptian mythology, Apophis is a great serpent that constantly fights Ra, the solar deity. At the end of each day, Apophis swallows the sun god, who manages to break free and kill the serpent in the morning, starting a new cycle of battle, which represents our understanding of day and night.
Speaking of astronomy, Apophis names an asteroid that will pass close to Earth in 2029. Discovered in 2004, it has been monitored since then due to its classification as a potentially dangerous asteroid (PHA), as it was estimated that would have a 2% chance of hitting Earth.
However, this possibility has already been ruled out. According to the latest measurements, Apophis will reach its closest trajectory to Earth (38,000 kilometers) on April 13, 2029.
A study by the Universidade Estadual Paulista (Unesp) and the Carlos III University of Madrid (UC3M) revealed characteristics of this celestial body and the possible impacts of its approach to Earth. The findings, published in the Monthly Notices of the Royal Astronomical Society, point out that particles from the asteroid could be ripped away by the effect of gravity exerted by our planet.
Researcher Gabriel Borderes-Motta, from the Department of Bioengineering and Aerospace Engineering at UC3M, says that the study focused on two investigations: what happens to the possible stones present on the surface and the orbit of the asteroid.
“The gravitational interaction between a planet and a body like Apophis can change the shape of the body, break the body into pieces, disintegrate possible loose rocks on the surface of the asteroidor even remove other bodies orbiting the asteroid (such as rocks, satellites, or rings),” Motta said in a statement.
How to search for an asteroid
Studies in the space context present numerous challenges, one of which is the impossibility of reaching asteroids directly. In this sense, the analyzes are conducted in the field of mathematics and physics, taking into account the greatest possible number of variables.
In this study, the scientists analyzed both the physical aspects of the asteroid, such as the shape and characteristics of the gravitational field, as well as the factors that can influence its trajectory and angle of inclinationincluding radiation, pressure or disturbance caused by proximity to Earth.
To explain the possible impacts to the asteroid from the near-Earth pass, it is necessary to take a few steps back. When we were in school, we learned in science and physics classes how the force of gravity works. It’s what keeps us grounded and allows the world to work the way we know it – with everything in place. More broadly, the planet also exerts gravitational force, being able to attract bodies around it.
In the research, the team performed a set of numerical simulations using a disk of 15,000 particles of different sizes in the environment close to that of the asteroid Apophis as a sample. The objective was to try to predict how the particles orbiting the asteroid might react to different situations and how these assumptions might influence the asteroid’s behavior.
The first set of simulations was designed considering only the gravitational perturbation of Apophis in 24-hour periods over 30 years. The second set of simulations included disturbances caused by solar radiation pressure. Three cases were proposed, in both sets, in which the asteroid had different densities.
“We evaluated a 340-meter polyhedron with uniform density in three different cases. In each case, the starting point was a different density of particles, from the largest to the smallest”, says Motta.
From these simulations, the researchers concluded that the lower the particle density and the higher the solar radiation pressure, the fewer particles remained intact.
In summary, in a scenario where Apophis has low density, approximately 90% of the loose rocks would be removed from its surface during the approach to Earth. In addition, the results showed that the approach of Apophis can slightly affect the tides and cause some landslides on the surface of the asteroid.
The approach of the asteroid to Earth could bring new discoveries in the area, with the possibility of improvements in the 3D modeling systems used to run space simulations. The researchers hope to be able to more accurately investigate the effects of Earth’s gravity on Apophis. NASA has a hazard list and tracks asteroids with orbits close to Earth.
Source: CNN Brasil