The asteroid’s flyby of Earth has changed its orbit, according to Yeomans and Chodas. Before its Earth encounter, asteroid 2011 CQ1 was one of the solar system’s so-called Apollo-class asteroids, whose orbits around the sun are mostly outside the orbit of Earth. [5 Reasons to Care About Asteroids] But during the Feb. 4 flyby, Earth’s gravitational pull warped the flight path of 2011 CQ1. Now the asteroid will spend “almost all of its time inside the Earth’s orbit” in what scientists call an Aten-class orbit, ..

It apparently also makes 2011 CQ1 the the closest non-impacting object in our asteroid catalog to date.

* Or for evil potentially although really it doesn’t pose any threat. Not unless it hits a satellite or the space station and the odds of that are .. well, super-ultra-mega extreme would probably be an understatement!

http://www.space.com/12086-asteroid-2011-md-buzzes-earth-pictures.html

for latest photos & more via space-dot-com.

Also see this on-line news item on it here :

http://www.abc.net.au/news/stories/2011/06/27/3254447.htm

for more.

@63. mike burkhart :

So there is nothing to worry about? Good I think we sould have a color coded system for Asteroids that cross the earths orbit. This sould be the system: Green Alert: Asteroid has no effect on Earth or the Moon Blue Alert:Asteroid will collide with the Moon. Yellow Alert: Asteroid will fragment some fragments will colllide with Earth Red Alert: Asteroid will collide with the Earth. These are the main dangers I see maybe some of you can think of others and expand the warning system.

Well there’s already the Torino scale :

http://en.wikipedia.org/wiki/Torino_Scale

devised for pretty much just this purpose.

@20. & #30 IVAN3MAN_AT_LARGE :

the Roche limit – the distance from the primary mass at which a satellite will disintegrate due to tidal forces exceeding the satellite’s own gravity – can be easily be calculated ..

Assuming that you’re good at calculating and maths generally which I’m very much *not* – Thanks for that info – good comments.

@66. Sparky : Does anyone know when the pretty radar images will be released?

Not sure about RADAR images but space-dot-com has an article with photos of it and more info. on this close encounter which I’ve linked & is ‘awaiting moderation’ currently.

As I clearly said, the relative velocity of the asteroid compared to Earth as stated by the article would only be 2232/mph at a distance of 7430 miles. That is well under the orbital velocity of an object at that distance. It may be true that both Earth and the asteroid are going 30 kl/sec, but that has nothing to do with the Earth and asteroid gravitational interaction. For that two body system, the only pertinent values are the relative motion of the asteroid compared to the Earth. As I also stated, an object in geostationary orbit at 22,236 miles from Earth has an orbital velocity of 6878/mph, that is exactly fast enough to keep it in orbit. The asteroid is much closer and going, relatively, much slower, so at that speed and distance the asteroid would be drawn in by Earth’s gravity and crash into Earth. The only way that wouldn’t happen is if the “speed up” by Earth’s gravity increased the asteroids velocity to greater than orbital speed at that distance. Since we know orbital velocity at 22,236 miles is 6878/mph, then the asteroid must speed up to far greater than 6878/mph since it is far closer to Earth than the geostationary satallites.

Again, the question I asked of Mr. Plait was how much was this speed up and how fast was the asteroid going when it passed by the Earth. Obviously well over 6878/mph, but how much more?

Now, if I just had access,,,

Gary 7

If gravity were a tractor beam affecting the asteroid and not the observer, then there would be forces between the two that could be measured/felt

g force from asteroid – (g force from Earth on side of asteroid nearest earth – g force from Earth at center of asteroid)

The g force on the side of the asteroid away from Earth will be the essentially identical:

g force from asteroid – (g force from Earth at center of asteroid – g force from Earth at side of asteroid farthest from Earth).

According to IVAN’s calculations, the differences in the parentheses will be less than the g force from the asteroid, so the astronaut will experience a reduction of the g force from the asteroid, but he will not float away!

Note that, considered separately, the g forces from the Earth will be about 250,000 times greater than the g force from the asteroid, but since we are in an orbit, it is only the differences that count.

No obvious sign of rotational modulation, but you wouldn’t expect that in 30 seconds (but who knows).

Thanks for posting!

http://sattrackcam.blogspot.com/2011/06/ot-close-encounters-of-rocky-kind-2011.html