Most people don’t give much thought to the rocks that are continuously swirling around the solar system until one gets too close to our planet, like the meteor that dramatically exploded over Chelyabinsk, Russia, almost three years ago. The aerial explosion was so powerful that almost 1,500 people sought medical attention in the days following the event, according to Russian authorities.
Here's a video compilation that shows what it looked like for those who were near the air burst:
On March 8, we will be visited by a space rock once again, but this time the asteroid will hopefully zip by without entering Earth’s atmosphere (if astronomers have the math right). What’s special about this flyby is that this is a return guest: Asteroid 2013 TX68 flew by two years ago at a distance of 1.3 million miles. But this time, there’s a lot of uncertainty about just how close the space rock will get.
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This asteroid is estimated by NASA to be about 100 feet in diameter, or about 50 percent bigger than the one that turned into a meteor over Russia three years ago. If it did enter Earth’s atmosphere, the energy released by its disintegration would produce about twice as much energy as the Chelyabinsk event, which is estimated to have released about 30 times more energy than the Hiroshima atomic bomb.
Because 2013 TX68 was only tracked for a relatively short amount of time, it’s harder to know with certainty what its future trajectory will be. Based on what we know now, the math for the March 8 flyby offers a wide range of possibilities, from between 9 million miles, which would be about 37 times the distance from the Earth to the moon, and 11,000 miles, which on an astronomical scale would be like a bullet grazing your head. That's well within the lunar orbit. The image above shows the distribution of the possible paths and their distance from Earth.
Based on the latest data, NASA now predicts that 2013 TX68 will pass at about 3 million miles from Earth. There's still a small chance that it could pass closer, but no more than 15,000 miles.
Thankfully, scientists at NASA’s Center for Near Earth Object Studies (CNEOS) are confident that there is “no possibility that this object could impact Earth” during the March 8 flyby. But this isn't the last we’ll hear from 2013 TX68: It'll also come close to Earth on Sept. 28, 2017. Don’t lose too much sleep in the meantime, though. NASA is confident that there won't be an impact. Looking further ahead, trajectory extrapolation shows that Earth and this asteroid will also come close to each other in 2046 and 2097, but NASA is also confident that there is no risk of impact at those dates.
"We already knew this asteroid, 2013 TX68, would safely fly past Earth in early March, but this additional data allow us to get a better handle on its orbital path," said Paul Chodas, manager of CNEOS. "The data indicate that this small asteroid will probably pass much farther away from Earth than previously thought."
Note: This story was originally written in February and has been updated with more recent information.