Detection of a physical effect that acts on the acceleration of the asteroid 300 meters Apophis confirms that the impact scenario against the Earth in 2068 it is still possible.
The investigator Dave Tholen and his collaborators from the Institute of Astronomy (IfA) of the University of Hawaii have announced the detection of the Yarkovsky acceleration on the near-Earth asteroid Apophis.
This acceleration arises from a extremely weak force on an object due to non-uniform thermal radiation. This force is particularly important for the asteroid Apophis, as it affects the probability of a ground impact in 2068.
All asteroids need to re-radiate the energy they absorb from sunlight as heat to maintain thermal equilibrium, a process that slightly changes the asteroid’s orbit. Before the detection of the Yarkovsky acceleration at Apophis, astronomers had concluded that a potential impact with Earth in 2068 was impossible. Detection of this effect acting on Apophis means that the 2068 impact scenario remains a possibility.
Will be approaching in 2029
Apophis is noteworthy due to its approach extremely close to Earth on Friday April 13, 2029, when the 300-meter-size asteroid will become visible to the naked eye when passing within the belt of communications satellites orbiting the Earth.
“We have known for some time that an impact with Earth is not possible during the close approach of 2029,” Tholen, who has been accurately tracking Apophis’ motion in the sky, said in a statement since his team discovered it in 2004. .
“The new observations obtained with the subaru telescope earlier this year they were good enough to reveal Apophis’ Yarkovsky acceleration, and show that the asteroid is moving away from a purely gravitational orbit by about 170 meters per year, which is enough to keep the 2068 impact scenario at game, “added Tholen.
The orbit calculations were performed by Davide Farnocchia of the Jet Propulsion Laboratory, who is a co-author of the paper that was presented at the 2020 virtual meeting of the Division of Planetary Sciences of the American Astronomical Society.
More observations are being made to refine the breadth of the Yarkovksy effect and how it affects the orbit of Apophis. Astronomers will know well before 2068 if there is any possibility of an impact.