An asteroid the size of the Eiffel Tower will pass over Earth on Friday (March 5) and leave our planetary neighborhood by 2029.
The space rock, named Apophis (an ancient Egyptian demon), was first seen in 2004 and will pose no danger to Earth during this week’s flight; will travel around the planet more than 40 times the distance from Earth to the moon.
But scientists are using this week as a rehearsal for the asteroid’s next passage, on April 13, 2029, when Apophis will approach Earth as many of its highest-orbiting satellites.
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“Apophis in 2029 will be a truly incredible observation opportunity for us,” Marina Brozović, a radar scientist at NASA’s Jet Propulsion Laboratory in California, told sister site Live.com Space.com. “But before we reach 2029, we are preparing.”
A short flight
Apophis is 1,140 feet wide (340 meters wide) and is made of stone, iron and nickel. It probably has a peanut-like shape, although astronomers will have a better idea of its shape when it passes Earth this week, according to NASA.
The asteroid takes a complete orbit around the sun about every 11 months. On March 5, it will come to less than 150 million kilometers from Earth at 8:15 pm EST (0115 GMT on March 6).
This is too far to be seen with the naked eye, but scientists will use planetary radar to imagine Apophis flying through NASA’s California’s Goldstone Deep Space Communications Complex and West Virginia’s Green Bank Telescope. They hope to determine the shape of the asteroid and find out more about how it rotates.
“We know that Apophis is in a very complicated state of spin, spinning and collapsing at the same time,” Richard Binzel, a planetary scientist at the Massachusetts Institute of Technology, told Space.com.
It’s getting close
This planetary radar study will provide researchers with a baseline for flying much closer in 2029, when Apophis will approach 31,900 km from Earth.
It is close enough that the Earth’s gravity could change the shape of the asteroid or scatter the boulders on its surface. How and if the asteroid changes as it flies will help reveal details about the asteroid’s inner structure, Binzel said.
At the closest approach in 2029, Apophis will be briefly visible to the naked eye over Western Australia, growing as bright as the stars in the Big Dipper.
It will be closest to Earth at 18:00 EDT on April 13, 2029, when it will be across the Atlantic – an ocean it will cross in just one hour. The asteroid will cross the United States until 19 pm EDT.
Apophis is named after an ancient Egyptian demon who personified chaos and evil, largely because astronomers initially calculated that there was a 3% chance that the asteroid would impact the Earth during its 2029 flight.
They have now shown that the asteroid will not collide with Earth in 2029, nor at its next crossing in 2036.
There is still a small chance that the asteroid will hit Earth in 2068, but the 2021 and 2029 flybys should provide astronomers with more information to calculate Apophis’ future.
This article was originally published by Live Science. Read the original article here.