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Hello, and welcome to this edition of SciShow.

Breaking news: You no doubt heard that the Earth just had a near miss with asteroid DA14, with a width of 50 meters. That's a biggun. And in an unrelated event, you probably also heard that a meteoroid with an estimated width of 15 meters fell to Earth over Siberia, the largest impact since the Tunguska Event of 1908.

On average, a 4-meter asteroid hits the Earth every year, so this is a much more significant event than usual. The meteor was captured by dozens of dashboard cameras that operate on the majority of Russian vehicles due to widespread insurance fraud and mafia scams, so, in a weird way, we kind of have jerks to thank for all of this wonderful footage we have of the event.

A shock wave was created when the friction on the atmosphere of the object, traveling at 30 kilometers per second (17 miles per second), heated the rock until parts of it vaporizes and ignited in the atmosphere. The blast was comparable to a small nuclear bomb being detonated at 30,000 feet. No injuries have been reported from actual impacts, but the air burst of the explosion blew out windows, causing damage and collapsing at least one building. Over 1,200 people have sought medical attention so far.

This meteoroid was likely made of rock, possibly with metals mixed in as well, but we will have to wait for further analysis before we know for sure. Asteroids of this size are nearly impossible to detect until they are, like, one or two days away from impact, and rocky meteorites are particularly difficult to spot because they're often very dark in color.

A quick note on terminology here: a meteoroid is any non-man-made object that enters the Earth's atmosphere, that can be upgraded to a fireball if the object is brighter than any of the planets (which this certainly was). The word "meteor" is actually used not to describe the object, but to refer to the streak of light in the sky. A meteorite is a meteoroid found on the Earth's surface.

This meteoroid up upon re-entry, and several distinct impact sites have been located. As DA-14, once again unrelatedly, harmlessly passes us by, with the destructive power to wreak far more havoc than this, it's a sobering reminder of how fragile we all are, and that we are at the mercy of cosmic circumstance... for now, at least.

Thank you for watching this episode of SciShow; if you want to keep up-to-date on the latest breaking news and also just getting smarter with us, you can go to youtube.com/scishow, and subscribe, and if you have an questions or comments or ideas, you can leave them in the comments below, or on Facebook or Twitter; we'll you next week.