New observations of the asteroid Apophis, which is believed to pose a small risk of affecting the Earth 2068, rule out any possible impact for at least a century.
As a result, after 17 years of orbital observations and analysis, ESA (European Space Agency) is removing the massive asteroid from its risk list, the space agency said in a statement.
Estimated in approx 350 meters wide, equal to the length of three football fields, Apophis has been in and out of the headlines for years, as astronomers have tried to pinpoint the precise orbit and the possibility of future effects.
Shortly after its detection in 2004, astronomers predicted two impact possibilities in 2029 and 2036Fortunately, they ruled out additional observations of the near-Earth object (NEO). Until now there was one small but troubling possibility of impact in 2068.
NASA’s Goldstone Deep Space Communications Complex in California and the Green Bank Observatory in West Virginia recorded new radar observations from Apophis in early March. They provided enough data about the asteroid’s orbit to ultimately rule out with certainty any impact on Earth for at least 100 years.
These last observations were possible when the asteroid made an approximation not so close on March 6, pass through the Earth at a distance of about 17 million kilometers (44 times the distance to the Moon). Although the asteroid was still fairly distant, astronomers were able to measure its distance accurately and fine-tune its orbit before approaching again. very close in 2029.
We know the position and orbit of the planets quite accurately, but for smaller objects such as asteroids, there is always some uncertainty in their trajectories. To complicate matters further, as asteroids pass through huge objects with tremendous gravitational forces, its trajectory is changed and this uncertainty is reinforced in its trajectory.
Before Apophis’s last radar measurements were taken, its orbit was understood accurately enough to predict a series of close-range safe approaches over the next few decades.
IT WILL BE CLOSE TO EARTH IN 2029
The next and closest of these passes will take place on Friday, April 13, 2029, when Apophis will succeed less than 35 thousand km from Earth and will be visible to the naked eye. Ten times closer than the moon, Apophis will be closer than satellites orbiting the geostationary ring.
At this distance is the gravity of the Earth will have a remarkable impact on the passing space rock, changing its orbit and increasing uncertainty in its orbit and possible future effects.
What was previously unknown is whether the 2029 flyby would change Apophis’ orbit in the ‘right’ way so that it collided with Earth in future orbit around the sun. “gravitational keyhole”, which would cause a potential (but still highly unlikely) impact in 2068.
Supported by recent radar and optical observations, the uncertainty in orbit of Apophis has collapsed from hundreds of miles to just a handful of miles when projected to be 2029 ”, explains Davide Farnocchia of NASA’s Center for Near Earth Object Studies (CNEOS).
Fortunately, these latest radar observations have reduced the uncertainty in Apophis’ trajectory so much that even with the trajectory altering effects of the upcoming 2029 flyby, any possibility of impact in 2068 or much later is ruled out.
ESA’s Asteroid Hazard List is a catalog of all nearby Earth objects that have a probability “nonzero” affect the earth. This means that, as unlikely as an object is likely to be hit, anything greater than zero will remain on the list.
Apophis has been a special case and has been stubbornly on the danger list for nearly 17 yearsDue to its large size it is understandable that it attracted a lot of attention and at times in its history concern.