Asteroid Trivia

Just about everything I know about asteroids I've learned in the past year and can be contained in a couple of blog posts.  Asteroid trivia, if you will.

One thing I learned is that asteroids with predictable orbits, according to NASA, don't pose any potential threat to earth "in the next hundred years."

Whew. But here's another fun fact: there are countless asteroids which are not visible, and therefore have no predictable orbits until they can be seen. These pop up at random, having been catapulted into our orbit from places like the Oort Cloud, and if they pass by close enough to earth, they can pose a threat. A bit like Russian Roulette, but on a cosmic scale.

There was one such fly-by in December, 2017; I believe it was discovered within the week previous to its close encounter with home. Here's a late-December snap of the "asteroid widget" from  NASA.  It's the bus-sized rock from the 28th.

I check Asteroid Watch when I get bored, probably 4-6 times per month on average. Today I noticed another (relatively) close encounter queued up as shown in the widget below.

Lo and behold, the January 17th entry, indicated with the jet-airliner icon, is there now and it's coming our way. To be sure, 335,000 miles, merely a whisker in space travel, is still a long way off in human-scale terms, but that's not the point. The point is that jet-, bus-, and sky-scraper-sized space rocks can come hurtling down our cosmic street from out of nowhere on very short notice, and not even NASA can detect them until they're good and ready to be detected. Often -- twice in the last 3 weeks, if that's often -- they don't RSVP until a few days before they show up for the party.

Carry on!

[Edit 1/18/2018] See the latest widget at right? A car-sized asteroid will pass between the earth and the moon on Jan 19th. Note that in the previous widget (above), which covered the period from 1/16 to 1/22, there was no such asteroid. This puppy is brandy-new, and came out of nowhere to be identified, what, 2 days before its debut in our area?