- An asteroid named Apophis, after the ancient Egyptian god of chaos, will fly through the earth on Friday night.
- The space rock is more than 1100 feet wide – wider than the Eiffel Tower is high.
- When Apophis returns in 2029, the orbit could cross the Earth’s orbit with large satellites.
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An asteroid of nearly four football fields wide is about to zoom in through the earth.
The space rock is named 99942 Apophis, after the ancient Egyptian god of chaos. It is wider than the Eiffel Tower is high: about 340 meters.
On Friday night at 20:15 ET, the asteroid will come within 10.4 million miles of the earth’s surface. This is about 44 times the distance between the earth and the moon. But Apophis’ next close flight on April 13, 2029, brings the asteroid within 19,000 miles of the earth – that is, between our planet and the moon. According to NASA, it will be the closest that any asteroid of the size of Apophis comes to the Earth’s surface that scientists knew in advance.
This future approach will even be close enough for the asteroid to collide with large satellite satellites.
The animation below shows the distance between Apophis and Earth over eight years. The blue dots represent orbiting satellites, and the International Space Station is in pink.
Prepare for the return of Apophis
Apophis is not visible to the naked eye tonight – you need a telescope at least a foot long to see it. But the Virtual Telescope project in Rome is hosting an online viewing session at 7pm ET.
The discovery of the asteroid made headlines in 2004, as astronomers at the time calculated that the chances of it hitting the planet in 2029 were slim. NASA scientists have since revised the estimate.
“We have known for some time that an impact on Earth is not possible during the 2029-near approach,” said Dave Tholen, a researcher at the University of Hawaii Institute of Astronomy who helped discover Apophis. October said.
Every time an asteroid is close to Earth, it’s a chance for astronomers to study the space rock and learn about its shape and rotation.
When scientists first spotted Apophis in June 2004, they only had two days to investigate it before the weather and technical problems got in the way. No images exist of the rock’s surface. This close pace, as well as that in 2029, will therefore help scientists study the composition of Apophis.
“Apophis’ close approach in 2029 will be an incredible opportunity for science,” Marina Brozović, a radar scientist at NASA’s Jet Propulsion Laboratory, said in 2019. “We will observe the asteroid with both optical and radar telescopes. We may be able to see details of the surface that are only a few meters large.”
During the 2029 flight, Apophis will be visible to the naked eye and appear as a fast-moving point of light that begins in the night sky over the Southern Hemisphere and moves from east to west around the world.
The NASA animation below shows Apophis’ path on April 13, 2029.
Apophis has a 1 in 380 000 chance of hitting the earth in 2068
Apophis is from the asteroid belt between Mars and Jupiter. So far, NASA knows that it consists of silicate rocks, nickel and iron. Radar images indicate that it looks like a peanut.
After 2029, Apophis will have more encounters near Earth and pass again in 2036 and 2068. There is no chance of an impact in 2036, but NASA’s calculations indicate a 1 in 380,000 chance that Apophis could strike in 2068.
Until last year, astronomers thought it would be impossible for Apophis to hit Earth in 2068, but that changed after Tholen’s team presented new research at the annual meeting of the American Astronomical Society. The group showed that the asteroid changes speed and direction over time.
The asteroid Vesta in space.
NASA
These changes are due to a process called Yarkovsky acceleration: when asteroids absorb energy from the sun, it radiates energy as heat, slightly changing their orbits.
Recent research has found that this is happening with Apophis.
The orbit of the asteroid shifts by about 558 feet per year, Tholen said – which is “enough to keep the 2068 impact scenario in play.”