posted on Mar, 2 2016 @ 12:49 PM
Here's a useful tip: if you copy&paste that long AU number into Google, followed by "to km" or "to miles" and click Search, it gives you the
conversion. Google doubles up as a calculator and a converter.
For example, "0.000251979577683381 AU to miles" gives approximately 23,423 miles. Keep in mind that this is counted from the centre of the Earth, so
we need to substract 3,959 miles (the mean radius of Earth) to get the approach distance to the actual surface. So, for the minimum close approach we
are looking at the asteroid passing just 19,464 miles from the surface of Earth.
That JPL page is also useful for predicting
where that asteroid
will appear in the sky and how bright it will be, allowing people with telescopes and binoculars to track it. This particular asteroid will be so
bright, it will be visible to the naked eye!
Quite uncanny, the date will be Friday the 13th. science.nasa.gov...