May 12th, 2016 something incredibly silent happened near to (or far from, depending on your perspective) our planet. It seems a comet (named 252P/LINEAR), roughly 100-400 meters in size, came closer to Earth than any other comet in recorded history. This sounds insanely frightening, right? A fast moving celestial object, around the size of a typical suburban neighborhood block or two, came closer than any other object of its classification to colliding with our fragile planet! Well, I have good news and I have bad news.
The good news is this “closeness” was actually very, very far. Further than our atmosphere, further than our orbital satellites, even further than the moon. In fact, the Hubble telescope (an observer of this event) website stated “The comet traveled within 3.3 million miles of Earth, or about 14 times the distance between our planet and the moon.” I’ve made (crudely) an image to scale showing you just how great this distance is. Each pixel in that image (900 pixels wide) represents 6.37×106 m; just about 0.04% greater than the radius of the Earth herself.
The danger to us? On a scale of “there was a thing that happened?” to “narrowly averted disaster”, this passing was more toward the former. The danger, however, is yet to come.
A few years ago expert American physicist, science educator, and everyone’s favorite superhero movie cameo, Neil DeGrasse Tyson, spoke of a terror among terrors: Apophis. This demonic asteroid (perhaps I exaggerate?) will come extremely close to us in 2029, close enough that it should actually dip into our atmosphere. Within this dip there is a specific distance where, if Apophis travels through, it will alter the asteroid’s trajectory such that on its next pass in 2036 it will fully collide with our planet. Now, the asteroid is smaller than the one that, in theory, was responsible for the extinction of the dinosaurs. However, as Tyson explains, the impact would probably create tsunamis that could destroy the whole Western seaboard of the United States and I imagine do untold destruction throughout East Asia, Hawai’i, the Pacific Islands, and probably Australia. Ouch. Watch the video below, then cry.
So my advice to you is this: Rest easy tonight, watch with trepidation in 2029, then (depending on how 2029 goes) potentially freak out for your remaining 7 years.
Maybe Bruce Willis and Ben Affleck will still be around to save us?