Apophis. It was discovered in June 2004.about 350 meters and about 27 million tons. And for weeks, the scientific community has been worried about a possible impact with our Earth in April 2029. Just a few weeks. Because since December 2004, archival data has shown that a collision is unlikely. And new data collected since then – in particular on the occasion of the passage of Apophis just 17 million kilometers from our Earth on March 6, 2021 – has further eliminated the risk. I’ is now sufficiently certain to rule out any influence with certainty for at least a hundred years.
“Collision is not the only possibility in such events”says Gabriel Berderes-Motta,(Spain), in . “The gravitational interaction between a planet and a body such as Apophis can change the shape of the body, break it apart, destroy any loose rocks on the surface of an asteroid, or even destroy other bodies by around an asteroid (rocks, satellites or rings). »
Together with his team, he analyzed the physical characteristics of Apophis. His form. As well as its gravitational field. And factors that could affect its trajectory and angle of inclination., For example. Or outrage over his passages in .
99942 #Apophis (Friday) On April 13, 2029, the meeting of Apophis with the Earth will be very close. The closest point in 2029, Apophis will pass about 10% of the distance from the Earth to the Moon. That’s very close for a space rock over 1115 feet (340 meters) in diameter! pic.twitter.com/2GG1BIHDL5
— ❍ (@CrisisCore) August 14, 2021
Apophis won’t come out unscathed
The researchers conducted a seriestry to understand exactly how the approach to our planet could affect the objects – particles, in fact – in orbit around Apophis. In the first case, taking into account only gravitational perturbations. In the second case, including perturbations due to pressure . All in 24 hour periods over a 30 year period. With different density of objects in orbit.
It is concluded that the anglethe number of asteroids is greater at a low density of objects in orbit (4°) than at a high density (2°). On the other hand, when the particle density decreases and the pressure increases, these objects in orbit struggle to stay intact. And finally, in the low-density scenario of Apophis, about 90% of loose rocks on its surface will be removed when approaching the Earth. The researchers also show that Apophis’ approach could have minimal impact on the tides and produce some changes. on the surface of the asteroid.
now hope to use the passage of Apophis near our planet in 2029 to refine their model. And it is better to predict the consequences of the approach of asteroids in general in the future.
350-meter asteroid Apophis will not pose a threat in the next 100 years
New observations of the asteroid Apophis rule out any risk of a collision for at least a century. Thus, after 17 years of observations and orbital analyzes, the asteroid was excluded from the list.potentials.
Articlepublished on 04.05.2021
With a diameter of around 350 meters, the Apophis asteroid has regularly made headlines since its discovery in 2004 due to the low, but not zero, hazard it had.with the Earth in the coming decades.
Shortly after its discovery, astronomers predicted two collision hazards:as well as . Additional object observations . However, until recently, there was little risk of a strike in 2068.
Impact excluded due to radar measurements
New radar observations of Apophis weretalk Goldstone Deep Space Communications Complex from NASA, California and Green Bank Observatory, West Virginia. They provided enough data on the asteroid’s orbit to definitively rule out any impact with Earth for at least 100 years.
These latest observations were made possible because on March 6 an asteroid passed close to Earth at a distance of about 17 million kilometers (44 times the Earth-Moon distance). Although the asteroid was still relatively far away, astronomers were able to accurately measure its distance and refine its orbit ahead of its next very close passage in 2029.
No passage through the “keyhole”
The positions and orbits of the planets are known very accurately, but for smaller objects such as asteroids, the uncertainty is often greater, especially when there are few observations yet. To complicate matters, when asteroids pass close to massive objects such as planets, they are deflected and the uncertainty about their path increases.
Until the latest radar measurements of Apophis, its orbit was known accurately enough to predict a series of safe approaches over the next few decades. The next and closest one will be on Friday, April 13, 2029, when Apophis will pass 38,000 kilometers from the center of the Earth (32,000 kilometers from its surface) and will be visiblenaked. Then the asteroid will be ten times closer than the moon, closer than (36,000 km above sea level).
Davide Farnocchia of(CNEOS) NASA, explains that ” thanks to recent optical and radar observations, the uncertainty about the orbit of Apophis has decreased from hundreds of kilometers to several kilometers in the forecast for 2029. These radar observations reduced the uncertainty of Apophis’ trajectory to the point where any risk of a collision in 2068 or much later was eliminated.
As a result, Apophis was removed fromand from .
” The discovery of Apophis and the early work done to track and understand its orbit took place when today’s planetary defense activities were still in their infancy. ”, explains Juan Luis Cano ofESA.
” The fact that this happened so early in the development of the discipline was a strong motivation for improving our ability to accurately predict the future.these interesting and potentially dangerous objects. With today’s removal of Apophis from the risk list, we close a very instructive chapter in the history of planetary defense. »
The trajectory of the large asteroid Apophis, which will collide with the Earth in 2029, has been changed.
Articlepublished October 31, 2020
Everyone has heard or almost heard about Apophis, an asteroid the size of the Eiffel Tower that will touch Earth in 2029. Without the risk of collisions, as shown by the calculations of astronomers. But recent sightings are prompting researchers to reassess the risks of his visit in 2068.
Since astronomers discovered in 2004 that Apophis – (99942) Apophis – is a potentially dangerous asteroid that is expected to come close to Earth in 2029,, 2068, 2085, 2088 according to their calculations, a celestial body with a diameter of about 340 meters became famous throughout the world. The researchers certify that for its passage at an altitude of about 31,860 kilometers above our heads on Friday, April 13, 2029 (the date is undoubtedly related to its fame!) – we will be able to see the heavenly cross with the naked eye. there is virtually no risk of impact with the Earth. So much the better, because if it rushed straight at us, it would cause significant damage on a regional scale. But, I repeat, NASA specialists are not afraid of either a collision or neither in 2036 nor in 2068.
Although… for this last date, we will have to revise the projections.
illustration of asteroid Apophis. © ESA
Apophis “leaves a purely gravitational orbit”
During a meeting of the American Astronomical Society’s Division of Planetary Sciences just held virtually with the research community, Davide Farnocchia ofNASA unveiled its latest trajectory calculations , which take into account the recent discovery of a small Yarkovsky acceleration effect observed by colleagues at the Japanese Subaru Observatory in Hawaii. This effect, associated with thermal radiation, is very weak and almost imperceptible, but still enough to make scientists revise their copies.
“New Observations […] show that the asteroid is deviating from a purely gravitational orbit by about 170 meters per year, which is enough to keep the possibility of a collision in 2068.” said Dave Tolen of IfA (Institute of Astronomy) at the University of Hawaii, who made the observations.
However, there is no point in panicking, as the calculations need to be revised in the light of future observations of the behavior of the asteroid. Astronomers say we should know ifwill or will not be in the way of a collision with our world long before his visit in 2068. To be continued.