Apophis: What you should know about the asteroid skimming by Earth in 2029
| Author | AARON REICH |
| Published date | 11 October 2021 |
| Publication title | Jerusalem Post, The: Web Edition Articles (Israel) |
Ultimately, however, this situation now seems unlikely thanks to additional data gathered by astronomers. As such, NASA has declared the planet free of risk from any asteroid impact for the next century.
But just what exactly is this asteroid that had so many people worried? Here is everything you need to know about 99942 Apophis.
When was it discovered and what did it look like?
The asteroid was first discovered on June 19, 2004 by astronomers at Arizona's Kitt Peak National Observatory. Original estimates had thought the asteroid was 450 meters in diameter. For comparison, that would make it taller than the 381-meter Empire State Building and 324-meter Eiffel Tower, and would make it around half the size of the 828-meter Burj Dubai, the tallest manmade structure in the world.
Later estimates put it at much shorter, with scientists ultimately estimating it around 370 meters.
In terms of classification, Apophis was classified as an Aten-class asteroid, meaning its orbit crosses over with Earth's orbit around the Sun, but it spends most of its time inside it. However, it will not stay that way, and is set to be reclassified as an Apollo-class asteroid after the anticipated close flyby due to its orbit now becoming wider.
What is its trajectory, and what chance did it have to impact Earth?
As an Aten-class asteroid, the orbit crosses over that of the Earth's. Due to proximity, size and speed (with it orbiting around 30.73 kilometers per second and completing an orbit around the Sun in about 0.9 Earth years), many worried that it would have struck the planet.
Originally, many feared the asteroid's trajectory could put it at risk of doing just that. At the peak of fear regarding this possibility, Apophis made waves for being the first asteroid to achieve a rating of four on the Torino impact hazard scale for two years.
But even from the beginning, the risk was never that high, and the odds seemed firmly in place that such an impact wouldn't occur.
But there were still reasons to fear that an impact could happen, and that surrounds the existence of the gravitational keyhole. Essentially, this is a small region of space influenced by a planet's gravity. If an asteroid were to fly through the keyhole at the right time, it could alter its orbit.
It was thought initially that, when Apophis was set to fly past Earth in 2029, it could...
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