Nov. 10 (Reuters) – Astronomers predict that about five and a half years from now, an asteroid as wide as the height of the Empire State Building will be in space within 20,000 miles (32,200 kilometers) of Earth. It is predicted that it will pass through the celestial body in all directions, making it the closest celestial object to it. In modern history, something that size would have come to our planet.
At that time, a spacecraft launched by NASA in 2016 is expected to be in position to provide a detailed study of this rare close encounter.
The mission, led by scientists from the University of Arizona, is expected to yield insights into planet formation and knowledge that could inform efforts to build defense systems against the possibility of an apocalyptic asteroid collision with Earth. There is.
At the time of its discovery in 2004, the asteroid Apophis, named after the demonic serpent that embodies evil and chaos in ancient Egyptian mythology, appeared to pose a dire impact threat to Earth, with scientists predicting that it could occur in 2029. predicted the possibility of a collision. Later, sophisticated observations were made. Eliminate impact risk for at least another century.
Still, on its next approach in 2029, the asteroid will be inside Earth’s cosmic cat’s whiskers. It is less than one-tenth the distance from us than the Moon, well within the orbit of several geostationary Earth satellites.
The spacecraft currently on its way to rendezvous with Apophis is Osiris-Rex, which collected soil samples from another asteroid three years ago, sent them back to Earth in a capsule, and parachuted into Utah in September. It became a hot topic.
The second act of the spaceship
Rather than retire the spacecraft, NASA renamed it OSIRIS-APEX (short for Apophis Explorer) and fired its thrusters to send it into orbit for its next target.
Regarding the Apophis expedition, Planetary Science Journal.
Apophis is a rectangular, somewhat peanut-shaped stony asteroid thought to be composed of silicate material containing mostly iron and nickel. It is approximately 1,110 feet (340 meters) in diameter and is expected to pass within approximately 19,800 miles (31,860 kilometers) of the Earth’s surface on April 13, 2029, and be visible to the naked eye for several hours, said Michael, deputy principal investigator. Nolan said. For a mission at the University of Arizona.
“It’s not going to be a spectacular show,” Nolan said, but it will appear as dots of sunlight reflecting off the night sky over Africa and Europe.
It is estimated that an asteroid this large approaches Earth approximately once every 7,500 years. Apophis’ flyby is the first such encounter predicted in advance.
Tidal forces due to Earth’s gravity would likely cause measurable perturbations to the asteroid’s surface and motion, altering its orbit and rotation. Tidal forces could cause landslides on Apophis, dislodging rock and dust particles to form a comet-like tail.
The spacecraft will observe the asteroid’s approach to Earth until it eventually catches up with Apophis. These images and data will be combined with measurements from ground-based telescopes to detect and quantify how Apophis changed as it passed Earth.
Osiris Apex will remain near Apophis for 18 months, orbiting and maneuvering around Apophis and even hovering above the surface, using its rocket thrusters to kick up loose material and explore what lies beneath. reveal.
Planetary science and defense
Like other asteroids, Apophis is a relic of the early solar system. Its mineralogy and chemistry have changed little over her 4.5 billion years, providing clues to the origin and development of rocky planets like Earth.
A closer look at Apophis could provide planetary defense experts with valuable information about the asteroid’s structure and other properties. The more scientists know about the composition, density, and orbital behavior of these celestial debris piles, the more likely they will be able to devise effective asteroid deflection strategies to reduce the threat of impact.
Last year, NASA intentionally crashed a spacecraft into a small asteroid in a planetary defense experiment, pushing the rocky object out of its normal orbit, marking the first time humans have altered the natural motion of a celestial body.
Although Apophis is much larger than its asteroid, it is smaller than the asteroid that crashed into Earth and wiped out the dinosaurs 66 million years ago.
Nolan said that if an asteroid the size of Apophis were to hit Earth at hypersonic speeds, it would not be large enough to pose an existential threat to life on Earth, but the ocean impact would cause a tsunami that would destroy large cities and regions. He said it could be devastating.
Nolan said that while it “wouldn’t be a global catastrophic event in the sense of a mass extinction,” the impact would “definitely be in the bad category.”
“When this object hits you, it’s traveling at many kilometers per second. And at that speed, it doesn’t matter whether it’s made of gravel, ice, rock, etc. It’s just a big, heavy object moving fast. ” Nolan added.
Steve Gorman reports from Los Angeles.Editing: Will Dunham
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