This was the view out the International Space Station’s cupola on Jan. 1, 2013, around 09:37 UTC, looking nearly straight down the gullet of Italy’s Mt. Vesuvius. Perhaps you’ve heard of it? Just a little more than 1,900 years ago, it blew its top in the most famous volcanic eruption in recorded history. About 16,000 people lost their lives that day due to pyroclastic flow—searing hot ash blasting outward from the stratovolcano’s maw.
The volcano has erupted many times since then, including in the 20th century. Got that? It’s still active. Now take another look at that photo, and let the volcano’s surroundings settle in to your mind. It sits just a few kilometers from Naples, and more than half a million people live in the volcano’s red zone—where destruction from a big eruption would be swift and brutal.
That’s why volcanologists consider it the world’s most dangerous volcano. Given all we’ve learned about volcanoes in the past few decades, I hope scientists would be able to give people a few days’ warning about an eruption. Science, after all, saves lives. (via Bad Astronomy)
Astronomers do not object to the idea of major collisions, only to major recent collisions. In any model of the solar system it is impossible to show the sizes of the planets on the same scale as their orbits, because the planets would then be almost too small to see. If the planets were really shown to scale, as grains of dust, we would easily note that the chance of collision of a particular comet with the Earth in a few thousand years is extraordinarily low.