© AFP 2016/HO/NASAThis artist's rendition released 20 April, 2005 by NASA shows a massive asteroid belt in orbit around a star the same age and size as our Sun.
A sizable asteroid is set to rocket past Earth next month, and scientists,
while confident it will not strike our planet, are nonetheless unsure how close it will actually come.Discovered two years ago, near-Earth object 2013 TX68 is roughly the size of a basketball court; fairly small, as asteroids go. TX68 is locked in an orbit that brings it near our planet every few years.
The next transit is expected to occur March 5. How close will it come to Earth? Scientists aren't exactly sure.
"The variation in possible closest-approach distances is due to the wide range of possible trajectories for this object, since it was tracked for only a short time after discovery," NASA officials said in a statement released Wednesday.
While there's no risk of impact, the asteroid could come as close as 11,000 miles from Earth, or inside the orbit of many satellites. For comparison, the Moon is 238,900 miles from Earth.
On the other extreme end of the scale, TX68's transit could occur 9 million miles away.
While the Earth will be either narrowly or widely missed next month, the asteroid, like the
Terminator, will be back. Scientists have listed three future dates in which there are small chances of impact. In September 2017, there is a 1 in 260 million chance of impact. In 2046, there is a 1 in 8.3 billion chance, and, in 2097, there will be a 1 in 5.3 billion chance.
"The possibilities of collision on any of the three future flyby dates are far too small to be of any real concern," Paul Chodas, manager of the Center for NEO Studies at NASA's Jet Propulsion Laboratory, said in a statement.
The odds are small, but even if an impact did occur, TX68 wouldn't bring about a mass extinction. At roughly 100 feet in diameter, TX68 is something less than twice as large as the near-Earth object that exploded over the Russian city of Chelyabinsk in 2013. While that meteorite certainly caused damage, it probably won't inspire any future Michael Bay movies.
TX68 would likely create a similar fireball in the sky, and possibly a small impact crater.
By comparison, the asteroid believed to have killed the dinosaurs, Chicxulub, was roughly 6 miles wide - larger than Mount Everest - and left a crater at least 93 miles wide. Even that space mountain was puny compared to an asteroid believed to have struck the Earth 3.26 billion years ago. Occurring during an era in Earth's history known as the "Late Heavy Bombardment," that object measured approximately 23 miles in diameter, and left a crater 297 miles wide.
In other words, TX68 isn't the one we need to worry about.
How can they be so certain it won't hit us if the range of possible trajectories puts it between 11000 and 9 MILLION miles.
The range just happens to come VERY close to us compared to the margin of uncertainty, which is, lets see, 90 times LARGER than the distance it will supposedly "definitely" miss us by...
To say that is hard to swallow would be an understatement. If the margin of uncertainty is that high, then for certain there are *no* guarantees that it will not hit us. The chances of such certainty being true and based on good calculations based on what we know, given the large uncertainty, are approximately the inverse of that number, 1/90, how convenient that in this situation they can make so sure of a statement!
Heck, discounting it hitting us, it could hit the moon and cause ejecta to be strewn all over, to wreak havoc on our satellites and spacefaring hopes for who knows how long to come as small pieces of moon rock are suddenly a new hazard around our planet and the moon.
I suspect the numbers were crunched a bunch of times until a publicly palateable statement could be made.
The fact that we know this is coming but haven't been able to track it since the last flyby really shows how unprepared we are for these sorts of threats...
The good thing is, if we really have no better idea about the trajectory, then the chances it will come anywhere near us are similarly small. This means that even if they knew it might hit us and released this info to assauge people's fears, it's a bluff that probably won't get called. A poker player's astronomy press release.