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Asteroid set to come closer to the Earth than the moon Nov. 8

nasa.gov

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Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#31

Post by lutorm »

brlewis wrote: post #17
Achshar wrote: post #2

Brace yourselves: the doomsday articles/memes/stories are coming.. PS will it be visible to naked eye? if yes then when and where and for how long and where in the sky? can there be a real time Google earth 3d simulation like NASA did for space shuttle launch?

The asteroid's surface is darker than charcoal at optical wavelengths. Amateur astronomers who want to get a glimpse at YU55 will need a telescope with an aperture of 6 inches (15 centimeters) or larger.

Yeah, it's the low albedo that kills you. Something that large made of ice would probably be quite bright.

Quick OOM calc: This thing has an area proportional to the moon of (200m/1700km)^2. The moon has an albedo of ~0.12. An object with albedo 1 would thus have a brightness of ~1e-7 of the Moon's. The full Moon has a magnitude of -12.7, so such an object would have a magnitude of -12.7-2.5log10(1e-7), or about 4.8. That's clearly visible to the naked eye at a dark site, but not very impressive.

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#32

Post by maaku »

blhack wrote: post #30
suprgeek wrote: post #13

Would be interesting if during the flyby our analysis revealed that it was made up of a Gold core or something :). Suddenly NASA might get a bunch of funding to prepare for the next flyby

I hear stuff like this a lot (mining asteroids for precious metals)... Wouldn't flooding the market with that much gold...crash it? Are we really talking about that many billions and billions of dollars worth of potential revenue from mining an asteroid? This all just seems like fun sci-fantasy.

Would it sound less far-fetched if we talked about mining asteroids for rare-earth metals, conductive metals like copper, industrial metals like titanium, etc?

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#33

Post by maaku »

Achshar wrote: post #7
nickpinkston wrote: post #5

Earlier quoted context omitted.

Good question - an aircraft carrier nearer than the moon? I can't imagine that'd be visible to the naked eye - even ships on the horizon disappear pretty quick. Then again you can see satellites sometimes, but that's like 4 orders of magnitude closer.

well but if it comes when its night and it has a tail long enough and is also bright enough,and is close to moon from the perspective of someone on earth and hence moon light makes it more visible, then.. who knows??

Asteroids don't have tails.

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#34

Post by CWuestefeld »

blhack wrote: post #30
suprgeek wrote: post #13

Would be interesting if during the flyby our analysis revealed that it was made up of a Gold core or something :). Suddenly NASA might get a bunch of funding to prepare for the next flyby

I hear stuff like this a lot (mining asteroids for precious metals)... Wouldn't flooding the market with that much gold...crash it? Are we really talking about that many billions and billions of dollars worth of potential revenue from mining an asteroid? This all just seems like fun sci-fantasy.

Wouldn't flooding the market with that much gold...crash it?

Well, presumably only a single party is going to recover that gold. If they dumped the whole load onto the market, it would crash. But if they release it slowly, then a greater supply from each batch would cause "inflation", so that the price they could get from the next batch would be lower. But they could still derive significant wealth before trailed off.

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#35

Post by johngalt »

blhack wrote: post #30
suprgeek wrote: post #13

Would be interesting if during the flyby our analysis revealed that it was made up of a Gold core or something :). Suddenly NASA might get a bunch of funding to prepare for the next flyby

I hear stuff like this a lot (mining asteroids for precious metals)... Wouldn't flooding the market with that much gold...crash it? Are we really talking about that many billions and billions of dollars worth of potential revenue from mining an asteroid? This all just seems like fun sci-fantasy.

You could make the same arguement without any sci-fantasy. Why bother starting a new gold mine? If it doesn't have any gold then it's wasted effort, and if it has tons of gold then it will just depress prices. So why bother exploring for any resources anywhere?

Instead consider a big hunk of asteroid mined gold sitting in orbit. Free storage, and quick delivery to anywhere in the world. Park it up there and drop pieces of it when the prices are high enough.

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#36

Post by lutorm »

hugh3 wrote: post #18
Cushman wrote: post #8

Earlier quoted context omitted.

Give science a little more credit :) The n-body problem is hard, but it's more like "we don't know if this same asteroid will hit the Earth 20 years from now" hard than "this asteroid could shift course at any moment!" hard.

The n -body problem is hard to solve analytically, but trivially easy to solve to arbitrarily high precision numerically.

Not entirely trivial. Because it is chaotic, it's not terribly well behaved. People who try to integrate the solar system forward in time have to put some effort into accuracy, and ultimately accuracy is limited by our limited knowledge of the initial state of the system.

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#37

Post by udp »

Achshar wrote: post #26
Achshar wrote: post #2

Brace yourselves: the doomsday articles/memes/stories are coming.. PS will it be visible to naked eye? if yes then when and where and for how long and where in the sky? can there be a real time Google earth 3d simulation like NASA did for space shuttle launch?

Its funny how here you get down voted for not reading a part of news thoroughly, or for that matter being wrong. (Or even for acknowledging that you were wrong), i am dying laughing here guys haha..! great work keep up.. EDIT: in case you couldn't fathom, that was sarcasm. EDIT 2: seriously, stop it! or reply as to why are you down voting? is it a crime to mistakenly post a comment and then acknowledge your mistake o…

General rule of thumb:

If you find yourself editing your post asking people not to downvote, it's time to delete it.

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#38

Post by Cushman »

blhack wrote: post #30
suprgeek wrote: post #13

Would be interesting if during the flyby our analysis revealed that it was made up of a Gold core or something :). Suddenly NASA might get a bunch of funding to prepare for the next flyby

I hear stuff like this a lot (mining asteroids for precious metals)... Wouldn't flooding the market with that much gold...crash it? Are we really talking about that many billions and billions of dollars worth of potential revenue from mining an asteroid? This all just seems like fun sci-fantasy.

Don't think "sell gold", think "make computers faster and cheaper."

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#39

Post by T-hawk »

ibrow wrote: post #19
Achshar wrote: post #11

Earlier quoted context omitted.

well moon moving out of its trajectory means alot more than tides (which in itself is pretty darn serious) IMO. The nights would be absolutely dark, also earth's rotation speed (AFAIK) is also affected by moon's gravity and bulges in both earth and moon's softer crust. Plus maybe we can adapt to such changes but our culture will change and it will be alot more difficult to live through that, imagine explaining to you…

Thanks for that. Quite a thought. Hopefully this will never happen - am assuming that the Earth has more chance of being hit than the moon (the moon being smaller and faster)? But would the nights be totally dark? I've experienced a lot of nights out on a boat on a moonless night and the stars provide a (relatively) large amount of light on their own.

The Moon isn't faster. The velocities you care about for Solar System impacts are sun-relative. The Earth and Moon have essentially the same velocity relative to the sun, since they orbit it together. The Moon moves a bit slower at new phase and faster at full phase because its Earth-relative velocity subtracts from or adds to its Sun-relative velocity, but the former is 1 km/sec and the latter is 30 km/sec, small potatoes.

As for who gets hit; Earth's mass is 81 times that of the Moon so it attracts objects 81 times as strongly. Really, the Moon would only get hit if Earth already pulled an object into a collision course or near-miss and the Moon just happened to get in the way at the right time. Earth has 4x the diameter so presents 16x the cross-sectional target that the Moon does.

Re: Asteroid set to come closer to the Earth than the moon Nov. 8

#40

Post by sukuriant »

maaku wrote: post #32
blhack wrote: post #30

Earlier quoted context omitted.

I hear stuff like this a lot (mining asteroids for precious metals)... Wouldn't flooding the market with that much gold...crash it? Are we really talking about that many billions and billions of dollars worth of potential revenue from mining an asteroid? This all just seems like fun sci-fantasy.

Would it sound less far-fetched if we talked about mining asteroids for rare-earth metals, conductive metals like copper, industrial metals like titanium, etc?

Gold is an industrial metal, though
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