Astronomers say they have to keep an eye on it Near-Earth asteroid apophysis To see how much space rock poses a threat to our planet as it passes closer in 2068. But don’t panic: the likelihood of impact still seems very low.
In some cases, the sun can heat an uneven planet, causing space rocks to dissipate energy from the asymmetry. The result can be a small pressure in a certain direction – an effect known as Yarkovsky acceleration, which can change the course of a path Planet By space.
Astronomers had not previously measured this solar push on the Apophis, so they did not take it into account when calculating the risk the planet poses to us in 2068. These previous calculations show the possibility of a slight effect – 1 in about 150,000.
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Now, a new study shows the planet is moving about 557 feet (170 meters) away from its previously predicted orbit in a year due to the Yarkovsky effect, said Nevo author and University of Hawaii psychoanalyst David Thole during a press conference in October. 26.
He explained during a virtual meeting of the Planetary Sciences Department of the American Astronomical Society that “basically, the diffused heat of a planet gives it a very small pressure.” You can find Press conference on YouTube here. It starts with the 22 minute mark.
“Warm hemisphere [of the asteroid] The pressure will be slightly higher than the cooler hemisphere, and the planet will move away from what it predicts as pure gravity, Tholen said.
Showing the orbit of the 1,120-foot-wide (340-meter) Apophis, he indicated that astronomers thought they had enough observations of eclipses collected in the years following its discovery in 2004 – to have more or less the effect in 2068. Those calculations, however, were based on orbits not affected by the sun’s rays. Ultimately, this means that we cannot rule out a threat to Apophis in 2068, Tho Tho said.
“The impact of 2068 is still ongoing,” Tholen said. “We need to track these asteroids very carefully.”
Fortunately, the asteroid will make a near (still safe) approach to our planet in 2029, including the Arecibo Observatory’s powerful radar dish – a ground-based telescope will be allowed – a more detailed look at the asteroid’s surface and shape. The apophysis will be so close that it will be visible to the naked eye, at the third intensity – as bright as Binary star Coro Caroli.
“Of all the dates, Friday, April 13th, April 13th [2029], Is when the flyby will happen, “Tholen said.” Clearly, the approach to 2029 is complex. We’ll let you know when that happens [Apophis] It passed like the earth, and it will make it easier for us to predict future impact scenarios. “
Tholen’s team made the discovery after four nights of observation in January and March with Japan’s Optical-Infrared Telescope Subaru Telescope at the summit of Maunkea in Hawaii. The researchers collected 18 exposures to asteroids with very high accuracy, with an error of only 10 milliseconds per observation. (A millionthsand is a thousandth of an arcsecond, an angular measure Scientists help measure global distance.)
“We’ve really nailed the condition of this planet very well,” said Tha We Lane. “This was enough to give us a strong investigation Yarkovsky effect, Which we expect to see for a while now. “
Tho Tho Lane noted that Apophis is difficult for astronomers, predicting (and then largely denying) “numerous impact scenarios” since it was first discovered in 2004. For example: Initially, scientists calculated the 3% chance of apophyses on our planet. 2029, according to a prediction by Thole, was quickly rejected after further observations showed the true path to the small world.
If there is a threat of influence, astronomers will know long before 2068 how to approach the problem. There are engineers from all over the world Develop ideas about how to deprive a dangerous asteroid From our planet, concepts ranging from gravitational tugs to “motion influencers” will knock the incoming rock off course.
A joint European-NASA mission will begin in 2022 to test and observe asteroid deflection on a space rock called Didimos. If everything is planned, NASA’s Double Asteroid Redirection Test (DART) The spacecraft will “Didmoon” the moon’s progress around Didimos. The European Space Agency will then launch the Hera mission in 2023 or 2024 and reach Didimos two years later, to see how well the motion impactor did to move the moon from its previous orbit.
NASA is dedicated Planetary Defense Coordination Office Which collects observations of the planet from a network of partner telescopes, and the U.S. Runs through scenarios for asteroid deflation with agencies or to exclude dangerous populations from incoming space stock (in the worst case). So far, decades of observations have found no imminent asteroid or comet threats to our planet.
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