In 2068, a near-Earth object was thought to have a small risk of impacting the Earth, but now radar observations have ruled it out.
Since its discovery in 2004, the asteroid 99942 Apophys has been identified as one of the most dangerous asteroids that could affect Earth. But as astronomers discovered Apophis, its performance assessment changed and its orbit was better determined.
Now, the results of a new radar observation mission combined with precise orbital analysis have helped astronomers to conclude that Apophis is not at risk of affecting our planet for at least a century.
With an estimated circumference of about 1,100 feet (340 m), Apophis quickly gained a reputation as a planet that could pose a serious threat to Earth when astronomers predicted it would come uncomfortably close in 2029. Thanks to additional observations of matter closer to Earth (Neo), the risk of impact was later ruled out in 2029, as there was a risk of potential impact in 2036 posed by other approaches. As of this month, however, there is still little chance of impact in 2068.
When Apophis made a flyby of the Earth’s distance around March 5, astronomers took the opportunity to use powerful radar observations to correct its orbit estimates around the Sun with extreme precision so that they could rule with confidence. Any Impact risk in 2068 and longer.
These images of the asteroid Apophys were recorded by a radio antenna from the Goldstone Complex of the California Deep Space Network and the Green Bank Telescope in West Virginia. The asteroid was 10.6 million miles (17 million kilometers) away, and each pixel has a resolution of 127 feet (38.75 meters). Credit: NASA / JPL-Caltech and NSF / AUI / GBO
“The impact of 2068 is no longer in the realm of possibility, and our calculations will show no impact risk for at least the next 100 years,” said David Farnochia. NASACenter for Neer-Earth Ject Budget Studies (CNEOS), administered by NASA’s Jet Propulsion Laboratory in Southern California. “With the support of recent optical observations and additional radar observations, the uncertainty of the orbit of the apophysis has dropped from hundreds of kilometers to just a few kilometers when it is projected in 2029. This greatly improved knowledge of its position in 2029 now provides its greater certainty. We can remove Apophis from the risk list. “
This animation shows a picture of the orbit of the asteroid 99942 Apophis as it zooms safely from Earth to Earth on April 13, 2029. Earth’s gravity comes within 20,000, 1,100 feet-wide (340-meters-wide) close to Earth. Miles (32,000 kilometers) from the surface of our planet. Dots are many man-made satellites that orbit our planet. The speed has been accelerated to 2000 speeds. Credit: NASA /JPL-Caltech
Farnochia Sentry was referring to the impact risk table. CNEOS Powered by, the table holds tabs on a few asteroids whose orbits bring them closer to Earth that the effect cannot be denied. With recent findings, the apophysis is no longer included in the risk table.
Relying on optical telescopes and ground-based radar to demonstrate close rotation of every object on Earth to improve long-term crisis assessment, CNEOS calculates high-precision orbits in support of NASA’s Planetary Defense Coordination Office.
Science opportunities
To arrive at the latest Apophys calculations, astronomers turned to a 70-meter (230 ft) radio antenna in the Goldstone Deep Space Communication Complex of the Deep Space Network near Bursto, California, to accurately detect the motion of the Epophys. “Although Apophysis has recently approached the Earth, it was still about 10.6 million miles away. [17 million kilometers] Away. Nevertheless, we were able to obtain incredibly accurate information about its distance Accuracy About 150 meters [490 feet]JPL scientist Marina Brozovich, who led the radar mission, said. “This campaign not only denies us the risk of any impact, it also establishes us for the wonderful opportunity of science.”
This animation shows the path with Earth where Apophis will appear on April 13, 2029. As the asteroid passes through the Atlantic Ocean, its path soon turns from red to gray – it is the moment of approaching. After a closer approach, the asteroid will go into the day sky and no longer appear. Credit: Marina Brozovic / JPL
Goldstone also worked in collaboration with the 100-meter (330-foot) Greenbank Telescope in West Virginia to enable imaging of the apophysis; Goldstone was transmitting while receiving the Green Bank – a “bistatic” experiment that doubled the strength of the received signal.
Apophys’s radar image appears pixelated, with a pixel resolution of 38.75 meters (127 feet), “which is a significant resolution, 17 million kilometers away, or about 44 times the Earth-Moon distance,” Brozovich added. “If we had binoculars as powerful as this radar, we would be able to sit in Los Angeles and read the dinner menu at a restaurant in New York.”
This animation shows the distance between the oph pofis asteroid and the Earth at the approach of the asteroid. The blue dots are many man-made satellites orbiting our human planet and represent the pink International Space Station. Credit: Marina Brozovic / JPL
As the radar team analyzes their data further, they also hope to learn more about the shape of the asteroids. Previous radar observations have suggested that the apophysis has a “bilobed” or peanut-like appearance. These nearby Earth asteroids have relatively normal shapes larger than 660 feet (200 m) in diameter; At least one in six has two lobes.
Astronomers are also working to develop a better understanding of the asteroid’s rotation rate and its surrounding spins (known as its spin state). That knowledge will enable them to determine the planet’s target with Earth as it faces our planet’s gravitational field in 2029, which could change the spin state and even cause a “planet”.
On April 13, 2029, the asteroid Apophys will pass less than 20,000 miles (32,000 kilometers) from the planet’s surface – closer to the distance of the geosynchronous satellites. During the approaching 2029, the Apophis will be visible to observers on the ground in the Eastern Hemisphere without the aid of a telescope or telescope. There is also an unprecedented opportunity for astronomers to get a closer look at the fossils of the solar system, which is now not only an immediate crisis for our planet but also a scientific curiosity.
“Apophys was a poster child for dangerous asteroids when I started working with asteroids after college.” “There is a definite sense of satisfaction in seeing it removed from the risk list, and we look forward to the science that we will be able to unveil in 2029 in the near future.”
