Now THIS Is What Scares The Piss Out Of Me!

Hey, there's always the chance I could be wrong!

Even better, I would think...

I think the last significantly large asteroid/meteorite to hit the Earth or explode in the atmosphere was in late 1990 over the North Pacific.

Exploded with about the yield of 10 kilotons (Hiroshima give or take).

4,700 (+/- 1,500) asteroids want to kill you.

No! HEED! ASTEROID! NOW!

This prospect worries me, too. Some time ago I watched a tv program in which an astronomer talked about a dumbell-shaped asteroid the size of Texas which moves in a orbit close to Earth's. He said a disturbance of sufficient size, such as those caused by collisions of other objects in nearby space, could nudge this thing into Earth's orbit and we would watch it growing larger and larger, day-by-day, until it eventually slammed into us.

Not a happy thought.

It's like Spootnik, spherical yet quite pointy!

Sounds like crackpottery. A Texas-sized object is too big to be dumbell shaped. The gravity of an object that size would always overcome its rigidity and make it a spherical dwarf planet.

Ceres is Texas sized.

ha, 16 feet. My dick is longer than that.

I feel much better now.

http://simulator.down2earth.eu/#

Not if it's recently formed asteroid, two smaller spherical or near spherical in shape would take a while to coalesce into a single sphere.

But .25KM is not 25 meters; it is 250 meters.

An asteroid 25 meters in diameter is .025 km in diameter, and would therefore have 1/1000th the volume of an asteroid .25 km in diameter.

Which one were you referring to in your post, a diameter of 25 meters (.025 km) or a diameter of 250 meters (.25 km)?

250 meters.

And Ceres is the biggest asteroid. Furthermore, it isn't anywhere close to Earth. Anyone talking about a Texas-sized object that could collide with Earth is either totally ignorant about their astronomy or making things up to scare people. Either way, they don't deserve to be taken seriously.

The very largest near-Earth asteroid, Ganymed (not to be confused with Ganymede, Jupiter's largest moon) is about 32 km (about 20 mi) in diameter. It's orbit never actually causes it to cross Earth's orbit, though it comes "close" (in astronomical terms). The next time it gets near Earth will be in 2024, when it will pass within 35 million miles of Earth. That is about 100 times the distance from the Earth to the moon. It is not a threat to the Earth, unless something serious happens to perturb its orbit.

Then an asteroid 250 meters in diameter would indeed have about 1700 times the volume of one 21 meters in diameter (the larger of the two that passed near Earth recently). Assuming similar composition, that implies about 1700 times the mass.

Did anyone else read this entire thread with Aerosmith playing in there head?

Forget asteroids. The entire Andromeda galaxy is coming! At 250,000 mph!

And I bet neither of the current parties has any serious plans for dealing with this, either. Here we are hurtling towards a cosmic smash-up at unthinkable speeds, when our entire galaxy smashes into a neighboring galaxy less than 4 billion years from now, and they are just playing around with economics and foreign invasions...

Based on the geological evidence, it takes at LEAST 1500 years.

Actually, from my understanding we are undergoing something of that nature right now, on a smaller scale. Our galaxy is part of a "galactic system" with about 30 "satellite galaxies" orbiting around the main body of the Milky Way. The two best known satellite galaxies are the Greater and Lesser Magellanic Clouds. (The Greater Magellanic Cloud is the largest satellite galaxy in the cluster, but the Lesser cloud is not the second-largest. There is in fact one that is bigger, but that is not clearly visible because it is hidden by the bulk of the Milky Way.)

Some of those satellite galaxies are close enough to the Milky Way that their orbit actually causes them to pass through the disk of the Milky Way sometimes. And it appears that there is one doing that right now. A huge cluster of stars is moving vertically, compared to the disk of the galaxy, in a way that indicates it came from outside and will leave again as it continues its path. Of course, such a passage never leaves either the satellite galaxy or the mother galaxy unchanged.

We just need to get one of these...

Everything I've read on the collision of the Milky Way and Andromeda is that it will not destroy anything. Think of it as a snow globe. You shake it and all the particles swirl around in waves and eddies. But there won't be any stellar or planetary collisions.

Well, I wouldn't say there wouldn't be "any." With that many billions of stars, some of them are sure to come close enough to each other that there will be planets torn out of their orbits, at the very least. Sure, in terms of the galaxies overall, the vast majority of the stars (and planets) will still be there, but there will be exceptions.

In general terms, however, you are correct: Galaxies are mostly empty space, and things will just slide together. Only the overall gravitational pull of the whole mass will slow them down enough that they "stick together" in the end, a process that, apparently, will take a couple of billion years.

Now that oughtta be a trip to look up at.