A whale-sized asteroid will zoom by Earth next week for the second time in recorded history
One hundred feet is about the size of a blue whale, but to be clear, 2013 TX68 is not considered a potentially hazardous asteroid and poses no catastrophic threat to human life on Earth.
Still, NASA's Center for Near-Earth Object Studies (CNEOS) has had its eye on this space rock since it was discovered in 2013.
The European Space Agency's NEO Coordination Center first spotted the asteroid while it was passing at a distance of 1.3 million miles away.
Now, according to the latest updates on the asteroid's location and orbit, the CNEOS has estimated that "2013 TX68" will fly past Earth on March 8 at a safe distance of 3 million miles away.
That's a distance of about 12.5 times farther away than the Moon is from Earth.
Unfortunately for asteroid spotters, this means that we likely won't have a chance to see the asteroid upon its closest approach.
"There is no concern whatsoever regarding this asteroid - unless you were interested in seeing it with a telescope," Paul Chodas, the manager of CNEOS, said in a press release. "Prospects for observing this asteroid, which were not very good to begin with, are now even worse because the asteroid is likely to be farther away, and therefore dimmer than previously believed."
Chodas admitted that because this asteroid is hard to spot, the data on its location is too sparse for the CNEOS to map its orbit completely. And this does leave a bit of uncertainty about exactly where the asteroid will be and when.
For instance, there's a small chance that on March 8, 2016, this asteroid could get as close to our planet as 15,000 miles away. That's still too far to do any harm, fortunately.
Twice as powerful as the Chelyabinsk event
While it's currently the size of a blue whale, Earth's atmosphere would make quick work of the asteroid, whittling it down to a fraction of its current size.
But it could still cause some damage.
For some idea of just how much, NASA calculated what might happen if 2013 TX68 were to enter Earth's atmosphere.
It would likely generate a radiant fireball that would explode close to the surface, but before hitting the ground. Such an explosion is called an air burst, and it's the blast wave from air bursts like these that can be dangerous.
The Chelyabinsk event in 2013, for example, generated three different air bursts, the most powerful of which released the equivalent energy of 500,000 tons of TNT.
2013 TX68 is about twice the size of the asteroid that broke up over Chelyabinsk, Russia, and NASA calculated that it would release twice as much energy - or about the same as 1 million tons of TNT. But, again, the chances of this happening on March 8 are zero.
However, March 8 won't be the last time we hear of 2013 TX68. It's expected to pass by Earth three more times this century in 2017, 2046, and 2097. But the odds of an impact are slim to none.
CNEOS estimated that the odds of an impact on Sep. 28, 2017 are 1 in 250 million - you have a far better chance of dying from a lightning strike than from this asteroid. And the odds of a later impact in 2046 or 2097 are even lower.
In the mean time, CNEOS will continue to monitor the asteroid.
"I fully expect any future observations to reduce the probability even more," Chodas said.