The asteroid 99942 Apophis has been considered one of the most dangerous asteroids with potential impact on Earth since its discovery in 2004. Now, scientists have revised this view after an accurate analysis of the asteroid’s orbit. .
Earlier predictions indicated that the 1,110-foot-wide asteroid could be too close for comfort in 2029 and 2036 and could have a small chance of affecting Earth in 2068.
During this distant flyby, astronomers used radar observations to gain better control of the asteroid’s orbit around the sun. Their results allowed them to rule out any risk that the asteroid would impact Earth in 2068. Previous concerns about 2029 and 2036 had already been sidelined due to the prediction of refinements and research.
“The impact of 2068 is no longer in the realm of possibility and our calculations show no risk of impact for at least the next 100 years,” said Davide Farnocchia, a navigation engineer and researcher at the Center for Studies. of Earth Objects Near NASA (CNEOS), in a statement.
“Backed by recent optical observations and additional radar observations, uncertainty in the orbit of Apophis has dropped from hundreds of kilometers to just a handful of kilometers when projected into 2029,” Farnocchia said. “This much improved knowledge of its position in 2029 provides more security about its future movement, so we can now remove Apophis from the list of risks.”
The CNEOS Center maintains a list of hazards, tracking asteroids with orbits that bring them closer to Earth, close enough to cause concern about a possible impact. Scientists at the center use radars and telescopes to study objects close to Earth and understand the dangers they can pose to the planet.
The CNEOS Center is managed by NASA’s Jet Propulsion Laboratory in Pasadena, California.
In order to observe Apophis and remove it from the list of risks, astronomers used the Goldstone radio antenna of the Deep Space Network near Barstow, California. This dish is one of three worldwide that allows communication with spacecraft through deep space. Scientists also relied on a collaboration with the Green Bank Telescope in West Virginia.
“Although Apophis took a recent approach to Earth, it was still nearly 10.6 million kilometers away,” Marina Brozovic, a JPL scientist, said in a statement. “However, we were able to obtain incredibly accurate information about its distance to an accuracy of about 150 meters (490 feet). This campaign not only helped us rule out any risk of impact, but prepared us for to a wonderful scientific opportunity. “
Although the images appear fuzzy, the resolution is quite strong considering that the asteroid was about 17 million kilometers away, that is, 44 times the distance between the Earth and the moon.
“If we had binoculars as powerful as this radar, we could sit in Los Angeles and read a dinner menu at a New York restaurant,” Brozovic said.
The data from this observation will help scientists learn more about the shape and speed of rotation of the asteroid. The current belief is that Apophis is shaped like a peanut.
Although Apophis poses no risk for the next century, it will encounter the Earth’s gravitational field during its overflight on April 13, 2029 and will pass less than 20,000 kilometers from the Earth’s surface. It is closer than satellites orbiting the Earth and 10 times closer than the moon.
Apophis will be visible to people in the eastern hemisphere with the naked eye, without the need for telescopes or binoculars. And astronomers will have the opportunity to study the asteroid closely.
“When I started working with asteroids after college, Apophis was the kid on the dangerous asteroid poster,” Farnocchia said. “There is a certain sense of satisfaction at seeing him removed from the list of risks and we look forward to the science we could discover during his next approach in 2029.”