Can Earth be struck by a meteor/asteroid and us never see it coming?

A couple of friends and I were thinking about this and I wanted to see what everyone else thought.

For all we know, the Universe is infinite. If this is true, then we cannot see the end of it even with our most powerful telescopes. There is no end. So, lets imagine that just further than the distance of our maximum sight, there is an object travelling 3 billion times faster than the speed of light and is headed directly for Earth. We would never see it coming.

 

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Mass can't travel faster than light, This is why the Large Hadron Collider is only able to accelerate proton packets to 0.99c prior to their collision. As there is a point where no accelleration force can be applied to the mass to make it go faster.

This is why your thought/question is impractical. If an object can't bridge 1c, i's hardly going to be 3,000,000,000c (American Billion)

 

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Nothing can go faster then light according to current scientific knowledge.

But as far as something hitting us with out us knowing is quite possible. A object can swing around the sun and come at us from the glare of the sun. We would get very little warning. Such an object made a very close pass a few years ago (don't remember when or the name). It passed us inside the moons orbit and we did not know about it until a day before its closest approach.

So the world can come to an end without warning..

Mind you its an interesting question. What is the fastest large 1km plus object we have ever detected. I know that some comets come in at around 80km per second. Have we seen anything faster in the solar system.

 

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If it came from underneath... like towards the Antarctica... that may be a place where we would not see it coming.

It would be unfortunate if the Earth experienced an instant obliteration. I would be extremely angry at fate... if I were alive to see it happen

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There are many good observatories that fully cover the Southern Hemisphere of the sky, so that "sneak attack” is very unlikely. Also it is very unlikely that the trajectory would pass thru even any point on the Earth's orbit and extremely unlikely it would do so when the Earth happened to be there.

However, it is quite possible that a small black hole could pass thru or near the solar system and kill us all. - Not immediately - it might take a few months. (That black hole would of course not be reflecting any sunlight back to Earth's Telescopes so is not detectable that way. Even "gravitational lensing" of distant stars would be undetectable - reasons are complex but basically it is transiting their image too fast.)

The gravitational impulse as it passes the solar system would alter the alter the orbits of all the planets, especially the outer ones, which very likely would be ejected from the solar system into extremely cold space.

I recognized this physically possible "cosmic disaster" many years ago. About 6 or 7 years ago when I became concerned that too few students were now willing to do the hard work an advanced degree in science requires when they can become better paid lawyers or stock brokers etc. I decided to try to scare them into developing more interest in science. So I wrote the book: Dark Visitor which has a 2.2 solar mass black hole pass thru the solar system 12 AU from Earth (missing Earth a plausible twelve times the distance to the sun from Earth).

I live in Brazil so timed the passing impulse to let me live. I.e. the new orbit of the Earth is more eccentricity but still less than that Mars has now. It was timed to make the winters in the Northern hemisphere milder and the summers cooler - sound nicer does it not? Well it is not - that kills everyone living in the Northern hemisphere, in less than a normal life span. In a decade all the worlds ports are useless (US not importing oil, etc.) as ocean levels are dropping as ice accumulates on Northern hemisphere land.

The really large snow storms come only in mild winter weather, and in the new orbit, that is all winter long. A summer apogee 11% greater distance is 23% less sunshine and the huge accumulations of snow do not all melt in the colder summers. This causes the albedo of the Earth to increase, at first in Canada and most of Russia, and then in the US and Italy as they too become permanently covered by snow. It takes a few decades for the tip of Florida to become covered by an ice sheet dozens of feet thick.

The North's winter snows are also much greater as then the Southern hemisphere's summer is receiving more than 12 times more solar radiation. This evaporates more ocean water and produces an almost permanent cloud cover up to mid Canada latitudes. That both supplies the volume of water for the "huge" snow falls and also increases Earth's albedo.

Earth is already just on the edge of an ice age. This small orbital change makes a permanent and historically most sever ice age ever in the Northern hemisphere. Here in Brazil we have problems too - every summer eve torrential rains fall. Rio and other coastal cities are washed into the sea by the floods. (I live in Sao Paulo - so do not have that problem and we can still grow rice.)

Dark Visitor is actually a physics book disguised as a cosmic horror story predicted to be coming soon. (Two chapters on climate, all of Keppler’s equations explained and used numerically, but never named, physic of formation of black bodies, neutron stars and much more is smoothly woven into the disaster story. - My target reader would never knowingly open a physics book so I avoid anything that resembles conventional teaching. Second half of it is the rich amateur astronomer's report (as interpreted by his historian friend, the book's author). This astronomer has been carefully observing Pluto (it is best observed from south of the equator now) for years. He was the first to notice and understand the slight perturbations of Pluto's orbit the still distant Dark Visitor is making. (Historian friend wrote the book because the astronomer is too busy now trying to refine his crude "Pluto perturbation trajectory" calculations by noticing "gravitational lensing" as the Dark Visitor passes in front of a background star. That keeps the physics understandable by even a pre-law students, etc.)

See more details, including a list of all the physics hidden in the text, at the web site under my name.

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*6% closer to sun in winter & 11% further away in summer with year 378 days long. Analysis is from a "three body" problem solved by finite time step program I wrote.

 

The asteroid belt formed from the primordial solar nebula as a group of planetesimals, the smaller precursors of the planets. Between Mars and Jupiter, however, gravitational perturbations from the giant planet imbued the planetesimals with too much orbital energy for them to accrete into a planet. Collisions became too violent, and instead of sticking together, the planetesimals shattered. As a result, most of the main belt's mass has been lost since the formation of the Solar System. Some fragments can eventually find their way into the inner Solar System, leading to meteorite impacts with the inner planets. Asteroid orbits continue to be appreciably perturbed whenever their period of revolution about the Sun forms an orbital resonance with Jupiter. At these orbital distances, a Kirkwood gap occurs as they are swept into other orbits.

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

 

I have my suspicions but right, we don't know.

That's 1 possible but unlikely theory.

As far as faster than light, we don't know.
Asteroids, definitely. Many come very close with little & sometimes no notice.
Meteors hit Earth every day.

 

Yes, it can. There aren't enough cameras pointing that way.

 

Certainly small meteors are not detected prior to burning up in atmosphere as "shooting stars." But any coment or meteor large enough to make significant damage to even a tiny village would be now because of the large number of CCD camera now looking for them by amateurs. Perhaps some "sun grazer" might get by as amateurs can not photograph sky near the sun. Hitting Earth without getting at least angular separation of Venus may be possible. I would need to think about it but believe that is possible for something coming from deep space on other side of sun. (Not part of the solar system - just passing thru.)

I almost joined a well organized global group as had 6 inch telescope and a broken old video CCD video recorder I could steal the CCD from. That group was actually more interested in cooperative development of software, data storage, internet shairing of data than in looking at the sky. There were 10s of thousands doing the sky watching already and the data storage and processing for objects not fixed against the background stars in the ccd images recorded was the more pressing problem.

I tried to find them again but here instead is a link that will help you understand how wrong your are and how good even small amateur telescopes with CCD detectors are at spotting approaching coments. This is not to say that they will be detected in time to do anything more than say you prayers just before they hit, but none of any significant size can get within a week's travel of Earth undetected now.

http://www.astrovid.com/technical_documents/Comet_Photometry.pdf

Here is the conclusion of that more than 14 year old link's paper:
"Our recent work on CCD photometry of comets enables us to perform routine V magnitude
measurements of comets down to 18th magnitude with precision exceeding those obtained by
any visual method."

There are at least a dozen wide field of view, large, profesional telescopes doing these comet, meteor searches also.

SUMMARY the full sky is now cotinuously monitored with telescopes that do collect a lot of light. If you want to hit Earth and damage it significantly without warning, use a small black hole.

PS in the decade and half since then digital cameras have advanced the CCDs greatly. One can probably be given all the high resolution CCDs you want for free as a defective pixel or two is not significant for this application. With many of them and wide field of view optics system, even only 20 amateurs could probably cover the entire sky now. The data will bury you without good software however. (16 in a 4 by 4 array of CCDs with 6meg pixels each taking 1 minute exposures all night automatically almost requires real time processing or burning a lot of DVDs, but next night you get all the data again etc. (Only store the interesting data.)

You need to look for a light spot, linear moving across pixels*, which BTW is the only thing a frog can see! (frogs eyes are not producing images. - Frogs are "fly detectors" with "Is it in tounge range?" automatic computer attached. Otherwise frogs are blind. The guy flying his piper cub airplane miles away at night is a pain to not false alarm on. Why internet shairing of the same "interesting events" is a good idea. -if a couple dozen observers all in US or Brazil's SW all agree the track is distant, then it is real.
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*after digital processing to remove all the appearant movement of the fixed stars (unless you have a tracking telescope set up, but why bother? unless telescope is stablized against the wind etc. - just let the computer do this.)

 

Still, it's like looking for a needle in a solar system sized haystack.

 

The "needle" is luminous and the data processed every night would fill a pickup truck with a ton of DVDs if it were all recorded. - I am just guessing -Perhaps it is a train load of DVDs? Also you need to (but seem not to) appreciate you are only watching at 4 ster radians, not a 3D space.

 

Short answer is "yes". We could impacted by a something big enough to screw up the whole earth that we might not detect until very shortly prior to impact. It is probably unlikely we wouldn't have any warning, but how long is 'long'. There's a good chance we wouldn't know until it was too late to do anything but have one last round and then pray.

Longer answer to several posts:

Nope. Nothing physical (including photons) moves faster than C. It's a good idea and the law. Seriously, our entire understanding of the universe requires that fact. The laws of Relativity indicate mass becomes infinite at C and length - in direction of travel - becomes zero. Can't get there from here.

No, the universe is not infinite. It is something on the order of 14 billion light years until one reaches the mid point and then starts getting closer to where one started. The universe is curved, it seems.

There isn't enough mass in the asteroids to make a real planet. It's more likely they are remnants of planetary formation than the remains of a broken planet.

All the foregoing is pretty well established in the astronomy and cosmology literature. If you want 'proof', do some studying.

And folks, even if earth is never struck by a large meteor ever; we'll all pass from this life anyway. None of us going to live forever in our current state.

 

I think you will find this number is wrong by about an order of magnitude.

 

Light speed is coincidentally just about a billion kilometers an hour. A million kilometers an hour is about a thousandth of cee, and a hundredth of cee is ten million kilometers an hour. Simple speed well below that of light would make it difficult to see an asteroid coming before it hits.

Also, of course, by the time we saw a projectile moving at .99 cee, it's right on top of us.

 

No 1 knows how big the universe is.

 

And how big is that? Not the incorrect size stipulated by Archie.

 

I don't think a meteor could hit us, without us knowing it. I'm sure that NASA is keeping us safe.

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A meteor???

 

Billie, a week isn't much time. You'd need powerful scopes giving you months and months of warning if you wanted the tiniest shot of being able to do something about it. A handful of low-power scopes isn't going to make any difference.