Bruce Willis, take the long weekend off.

The largest asteroid in more than a century will tumble by Earth Friday in the closest encounter by anything that size in more than 100 years. The asteroid, named Florence, is one of millions of pieces of rocky, grey primordial space debris that’s been flying around our solar system for a few billion years.

It will come within about four million miles of Earth, which seems pretty far. It is in terms of an Interstate vacation with toddlers. But in the vast scale of space, four million miles is just around the corner, if space had any corners.

The Earth itself travels through space at eight miles every second, which means we move through space four million miles in less than a week. We moved almost eight million miles just during the brief White House tenure of Anthony Scaramucci.

NASA has been tracking Florence by ground-based radar in California and Puerto Rico for two days now in hopes of determining its precise size and details down to 30-feet. Currently, Florence is estimated to be just under three miles across. Scientists say that’s about the size of 30 Egyptian pyramids, which would indeed make a special splash or decent dent if we collided.

The doozie asteroid that wiped out the dinosaurs and darkened Earth for some years is estimated to have been only twice as large as Florence, about six miles wide. Other asteroids have come closer to Earth in recent times. But they’ve been smaller.

Large asteroid encounters with Earth are relatively rare, you may have noticed. Our protective atmosphere handles a car-sized asteroid about once a year, they say, heating it on entry and burning it up before impact.

According to NASA, tomorrow’s fly-by is Florence’s closest encounter of the real kind since 1890 and the nearest it will be until after 2500, when another Clinton or Bush will surely be running.

Here’s something else to think about though. We didn’t actually know anything about Florence’s existence until 1981. What other near-Earth rocks are hurtling through the neighborhood that we remain unaware of?

On second thought, let’s keep Bruce Willis’ number handy.

Tags: asteroid NASA