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Asteroid Apophis Just Got Bigger
astroengine writes "As the potentially hazardous asteroid makes closest approach to Earth today, astronomers using the European Herschel Space Observatory have announced something a little unsettling: asteroid 99942 Apophis is actually bigger than we thought. Herschel astronomers have deduced that Apophis is 1,066 feet (325 meters) wide. That's 20 percent larger than the previous estimate of 885 feet (270 meters). 'The 20 percent increase in diameter, from 270 to 325 m, translates into a 75 percent increase in our estimates of the asteroid's volume or mass,' said Thomas Müller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and lead scientist of the study. In addition, the space telescope has re-analyzed the albedo of the space rock, providing a valuable heat map of the object's surface — data that will improve orbital trajectory models."
...does this mean we're more likely to die or less likely to die?
Someone had to say it.
Astronomers. My asteroid is bigger than your asteriod. Is not! Is too! Is not! Is too!.....I guess we'll both need grants for a few years to study the question.
Does this mean we need to prepare for a Goa'uld invasion?
SG-1 Will take care of it no doubt.
They're also saying that Apophis will pass within 36,000 km of Earth in 2029. Now that's not missing us by much.
Will my homeowners insurance cover any damage should this hit, or would it be considered "an act of God"?
asteroid 99942 Apophis is actually bigger than we thought
http://www.youtube.com/watch?v=PzZ4i8aWs_s
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BMO
"In April 2029 the space rock will still make a very close pass with our planet, coming within 22,364 miles"
Being the skeptical engineer, I would say there is also a chance that on its multihundred million mile trip over the next decade and a half all it would take to nudge the orbit a slight amount to make the close pass a hit would be an encounter with another large object that affected its orbit ever so slightly...the wrong way.
That orbital perturbation is random & would simply not be predictable.
Well, obviously the asteroid had passed through the trans-fat and high-fructose corn syrup nebulae between photos.
No, it just means that the astronomers are using the telescope that doesn't have the mirror with the words "objects are closer than they appear" on it.
Well first of all, they successfully predicted it would be here now, so they must have done something right.
The issue is that mass is irrelevant when you're measuring how something is affected by gravity. This was the point of the (possibly apocryphal) experiments of Galileo. The force of the gravity on the object is proportional to the mass of the object, but the force needed to move the object is also proportional to its mass, so it all cancels out. Apophis will continue to follow the same path, no matter what its mass is.
Now technically speaking the weight of the object does affect the rate at which other things fall towards it. (If you drop a 2kg weight the earth "falls" upwards twice as fast as if you drop a 1kg weight, but the difference is obviously too small to be measured.) So if Apophis encounters an object close to or smaller than its own mass it will make a difference. However i'm pretty sure they aren't able to predict encounters with objects that small, so if it does happen it will be a totally unexpected event with an unknown affect on its orbit anyways.
This Space Intentionally Left Blank
Once it's going away, how would we catch it? It'll be going 25 km/sec relative to us.
Simulations of nuclear weapons vs. asteroids typically show that the nukes mostly just heat the asteroid up. In space, there's no atmosphere to superheat into an airburst, so a nuclear explosion consists of the vaporised remains of the bomb and the delivery vehicle and a lot of radiation. At the speeds involved, there's only about a 50 millisecond window to even detonate a nuke near enough to an asteroid that's approaching us for it to have any effect. Even if the timing is just right, a maximum of 50% of the energy of the nuke is going to hit the asteroid, and it's really going to be more like 10%. As has been mentioned, we pretty much have to hit the asteroid on approach, because it's going to be a lot harder to catch up to while it's moving away. If we do manage to blow it up, then we go from one large body travelling in a fairly predictable path to a number of objects of varying size travelling on less predictable paths, so if it's not going to hit us, we're better off not blowing it into pieces that might hit us. Also, we might have a lot of nuclear warheads, but we don't have anywhere near as many rockets capable of getting the payload to the asteroid. Nuking it might be cathartic, but there are a lot of problems with the idea.
The issue is that mass is irrelevant when you're measuring how something is affected by gravity. This was the point of the (possibly apocryphal) experiments of Galileo. The force of the gravity on the object is proportional to the mass of the object, but the force needed to move the object is also proportional to its mass, so it all cancels out. Apophis will continue to follow the same path, no matter what its mass is.
True, but a higher mass relative to the diameter means that solar winds have a lesser effect. Granted, that effect is small compared to the pull of Earth, Sol, Jupiter and (when close) Luna, but it might still be significant in calculating whether we're going to get hit or not.
You asteroid alarmists are getting ridiculous, there isn't a scientific consensus that asteroids even exist, let alone that they are caused by humans
This is a joke. I am joking. Joke joke joke.