An asteroid the size of the Eiffel Tower will fly past Earth Friday (March 5) and will be out of our planetary neighborhood until 2029.
The space rock, called Apophis (an ancient Egyptian demon), was first seen in 2004 and will not pose any danger to Earth during this week’s long-haul flight; it will travel around the planet at more than 40 times the distance from the earth to the moon.
But scientists are using this week as a dress rehearsal for the asteroid’s next pass, April 13, 2029, when Apophis gets as close to Earth as some of the highest-orbiting satellites.
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“Apophis in 2029 is really going to be an incredible observation opportunity for us,” Marina Brozović, a radar scientist at NASA’s Jet Propulsion Laboratory in California, told Live Science’s sister site Space.com. “But before we get to 2029, we are preparing.”
A quick fly
Apophis is 340 meters wide and made of stone, iron and nickel. It is likely roughly the shape of a peanut, although astronomers will have a better idea of its shape when it passes Earth this week, according to NASA.
The asteroid makes a full orbit around the sun about every 11 months. On March 5, it will come within 93 million miles (150 million kilometers) of Earth at 8:15 p.m. EST (0115 GMT on March 6).
That’s too far to see with the naked eye, but scientists will use planetary radar to image Apophis as it flies by using NASA’s Goldstone Deep Space Communications Complex in California and the Green Bank Telescope in West Virginia. They hope to determine the asteroid’s shape and learn more about how it rotates.
“We know that Apophis is in a very complicated spin state, it’s sort of twisting and tumbling at the same time,” Richard Binzel, a planetary scientist at the Massachusetts Institute of Technology, told Space.com.
To come closer
This planetary radar study will provide researchers with a baseline for the much shorter fly-by in 2029, when Apophis will get as close as 19,800 miles (31,900 kilometers) to Earth.
That’s so close that 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 by helps reveal details about the asteroid’s inner structure, Binzel said.
At its closest approach in 2029, Apophis will briefly be visible to the naked eye over Western Australia and become as bright as the stars in the Big Dipper.
It will be closest to Earth at 6 p.m. EDT on April 13, 2029, when it will be over the Atlantic Ocean – an ocean it will cross in just an hour. The asteroid will cross the United States at 7 p.m. EDT.
Apophis is named after an ancient Egyptian demon who personified chaos and evil, largely because astronomers initially calculated that there was a 3 percent chance that the asteroid could hit Earth during its 2029 orbit flight.
They have now shown that the asteroid will not collide with Earth in 2029, nor on its next pass in 2036.
There’s still a slim chance that the asteroid could hit Earth in 2068, but the 2021 and 2029 flybys should give astronomers more information to help them calculate Apophis’ future.
This article was originally published by Live Science. Read the original article here.