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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.
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So we used our super advanced technology to know precisely where this asteroid will be in like 2042 or whatever but we were off by almost half its mass (or volume)? Anyone see a little disconnect there? Especially since other solar system bodies' gravitational fields will affect it differently if it weighs double what we thought. I knew it was a load of alarmist, headline-grabbing BS.
So, re-read what you said and think about that. You'll come to the conclusion that you should be quite alarmed because we don't know what might hit us when. We also didn't know about Eris, a proto-planet more massive than Pluto until 2005. That means we're pretty damn blind, and that stuff we can see we can't see very well and thus can't make very precise predictions about them.
If anything, to me that means we should be pretty concerned about this situation and seek to rectify it ASAP. We need to swap the NASA and armed force's budgets. Get some space infrastructure in place to protect us from other asteroids: Get a few big rocks of our own orbiting to use as slingshots or gravity tugs, etc; Much better telescopes, esp. wide field systems; Self sustaining colonies off-world so all our eggs aren't in one basket. We can squabble about Oil after we're sure we're not going to be extinct.
The dinosaurs regarded chicken little as an Alarmist when she saw a meteor shower and said the sky was falling. Turns out she was right, only the dinosaurs in the flight program survived.
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.
And you can see it debunked here: http://podcast.sjrdesign.net/shownotes_049.php
He made a vague prediction about a "red meteor" in 1981...mentioned no dates or size. Then in 2008 he spoke of it again, this time specifying dates and size.
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.
Given we have survived the last umpteen million years we can figure the odds are fairly low. Even for asteroids like this, it is not a planet killer. Of course humans are populating more areas in bigger numbers than we were say, a couple of thousand years ago, so anything hitting has higher odds of doing damage but the human race is fairly safe. No one knew about these until recently so knowing does make you nervous. At least they are making good progress.
And Eris is about the same size as Pluto. We couldn't see if because it was very very far away. We have found a bunch more now too.
http://en.wikipedia.org/wiki/Trans-Neptunian_object#Notable_trans-Neptunian_objects
Not knowing about Eris doesn't mean there is likely to be a big planet on target to hit earth. If Eris was inside the orbit of Nepture it would have been discovered much quicker. Don't read those crazy panic websites without doing some reading of the mainstream sites to put it into perspective.
If it is within a few kilometres (=1000m) then he had a lot of wriggle room.
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.
The only reason to blow up the asteroid while it's heading away would be if it were coming back. But if it's coming back, blowing it up "as it goes away from us" is really just blowing it up on the way in, just further ahead of time. It's still a bad idea for exactly the same reasons, you're just executing the breakup so the shrapnel with a total mass identical to the original asteroid shotgun-blasts into the planet on the next pass rather than on this pass. If you're trying to make it not head in our direction, it's actually a lot easier to do that if you don't break it up.
I imagine in your head you're picturing some kind of massive explosion that sends the mass of the asteroid flying in all directions, rather than just cracks the rock up into smaller asteroids in the same orbit. That would work, if we had something powerful enough to do that. A nuclear bomb wouldn't, however. Might as well suggest we use a stick of dynamite. At the time it was invented, in the popular imagination you could do anything with it, but really, it's just dynamite. Nowadays, since nuclear bombs are the most powerful explosive devices ever invented, again in the popular imagination you can do anything with them. But really, no. An asteroid large enough to really worry about is too large to be much affected by a nuclear bomb.
"Convictions are more dangerous enemies of truth than lies."