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Big Asteroid (With Its Own Moon) To Have Closest Approach With Earth Today
An anonymous reader writes "Asteroid 1998 QE2 has an estimated diameter of 2.7 km. This asteroid will have a close approach with Earth at about 15.2 LD (Lunar Distances = ~384,000 kilometers) or 0.0392 AU (1 AU = ~150 million kilometers) at 2059 UT on 2013 May 31 and it will reach the peak magnitude ~10.8 on May 31 around 2300 UT."
Radar images of the asteroid taken Wednesday show that 1998 QE2 has its own tiny moon, about 600 meters wide. Phil Plait explained how the images were taken, and what further information we gleaned from them. 'The very presence of the moon is a good thing. By measuring how long it takes to go around the primary, the mass of the primary can be found using math known for centuries (the more massive the big asteroid, the faster the moon will go around it at a given distance). We also know the size of the primary, so that means we can find its density, and therefore what it’s made of (probably mostly rock).'
It's a space station!
So I put an asteroid on your asteroid, so you can watch a flyby while you're watchin' a flyby!
"When information is power, privacy is freedom" - Jah-Wren Ryel
(probably mostly rock).
At least it's not some kind of smooth alternative. But I was hoping for something heavier, maybe with metal influences.
Everything is better with chainsaws.
... that the tidal gravitational wave of Earth/Moon will disrupt the small couple?
Shut it... You just gave Michael Bay a terrible idea for a disaster movie.
15.2 LD (Lunar Distances = ~384,000 kilometers) or 0.0392 AU (1 AU = ~150 million kilometers)
Or maybe we could just say "around four million miles" and be done with it. Add in the metric conversion if you want, but really, do we need an explication of "AU" and "LD" for this story? Just convert it to human readable format. It's one of those things that "journalists" do...
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
No, not much chance of that. Gravity, like other forms of energy, falls off according to the inverse square rule. If object B is twice as far away as object A it is only attracted at 1/4 (1/2^2) the force. Object C is five times further away as Object A, only gets attracted 1/25th as much (1/5^2). These are far enough away that their mutual gravity is a much stronger force than that of the Earth/Moon system, so our gravity applies effectively equal force on both objects. Clear as mud?
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
Gee, that moon sure is reflective of radar. Almost like it was specular and made of metal.
Don't take life too seriously; it isn't permanent.
I can't imagine anything joining the world together in unity to create a real space defense (and get us out there and off this rock) than a few million people getting killed at once.
You missed the memo. It was in the We The Geeks NASA G+ hangout today. Some folks actually care about the issue enough to put their money and time where their mouth is and thus are actually doing what you propose.
How cool is this. 1.7 miles of orbiting rock. Let's capture that sucker and bring it where we can use it.