This asteroid passed by us in the last few hours. It's about the size of a city block 1600ft (500m), and passed by at about 14 moon distances (5.3 million kilometers). That fairly big and very close.

The scary bit is that it was only spotted a few days ago.

http://www.space.com/16154-asteroid-2012-lz1-earth-flyby.html

This asteroid passed by us in the last few hours. It's about the size of a city block 1600ft (500m), and passed by at about 14 moon distances (5.3 million kilometers). That fairly big and very close.

The scary bit is that it was only spotted a few days ago.

http://www.space.com/16154-asteroid-2012-lz1-earth-flyby.html

Thanks for posting this article. I did see another a little earlier.
(Like, wow.) The scary bit is that it was only spotted a few days ago.
Love, the advance warning.

But, this one and that one discovered a month or two ago, were both not spotted until they were right on top of us. That's the scary part.

And that one found a month back (I can't remember it's name off-hand), has a chance of whacking us with a Tunguska style impact on our pole, when it comes back in about 20 years IIRC.

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#resist

But, this one and that one discovered a month or two ago, were both not spotted until they were right on top of us. That's the scary part.

And that one found a month back (I can't remember it's name off-hand), has a chance of whacking us with a Tunguska style impact on our pole, when it comes back in about 20 years IIRC.

We know we don't know where the majority of earth orbit crossing rocks are. One is sure to hit us some day. Idiot politicians are busy cutting the NASA budget. Obvious conclusion politicians don't care about humanity, but about where the next bribe is coming from, and it isn't pure science.

The Planetary Society is looking. http://www.planetary.org/explore/projects/neo-grants/ If you are concerned about it, I'd suggest reading up on it and perhaps making a donation.

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I have mentioned this previously, but I think it will take a major hit on the moon, easily visible from earth, to wake up those who are in charge about the real danger we face from a large comet or asteroid strike. I once thought that Shoemaker-Levy 9 was going to supply the wake up call but other than a few paltry million dollars for more telescopes and some scientific studies that have brought little in additional concrete plans we are still as defenceless as ever. Hopefully we will get such a warning and not a direct hit to bring home the point.

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

to wake up those who are in charge about the real danger we face from a large comet

I would not be embarrassed to tell you that there is most likely no one at all in charge.

After we find them, then who does what with what ??

After we find them, then who does what with what ??

We all go outside and kiss each other's behind and watch it hit.

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After we find them, then who does what with what ??

That was the point of my post. I wasn't inferring that nothing is being done at least in the identification arena as with the NEO program. Maybe there is nothing that can be done to deflect or destroy a big rock or snowball falling from space from a practical standpoint but it's stupid not to try.

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

After we find them, then who does what with what ??

That was the point of my post. I wasn't inferring that nothing is being done at least in the identification arena as with the NEO program. Maybe there is nothing that can be done to deflect or destroy a big rock or snowball falling from space from a practical standpoint but it's stupid not to try.

Depends on how far in advance it is spotted. Days from impact and how do you build a rocket that fast? A couple of years from impact and we can do something and it doesn't take a big nudge either. That is why cataloging them is so dang important. But we can't do anything about the one dropping from the Oort cloud today with our name on it, we won't spot it until it is too late.

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I was also just thinking about how to change trajectory. Given time even a small rocket engine has the power to change course. The issue is the damn rock is going to be rotating. How do you push on a rotating rock in one direction? We would never be so lucky as to have the axis of rotation match up with the direction we need to push.

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I'm not too sure of the physics here, but if you alter the spin rate its possible that you will alter the drag, and so the trajectory?

As for not having an access in the right direction - any direction other than towards an impact with earth is a "good direction". This may of course mean altering its Earth-relative velocity such that while it still intersects our orbit it does so at a point that is out of harms way for now (buys us time)

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

here is another near miss? Video included.


Astronomers catch video of near-miss asteroid

Sixth-closest near-Earth encounter tracked by telescope.


A small asteroid called 2012 KT42 came within three Earth radii of striking the planet on 29 May, but slipped past. The event was the sixth-closest encounter of any recorded asteroid.

I'm not too sure of the physics here, but if you alter the spin rate its possible that you will alter the drag, and so the trajectory?

As for not having an access in the right direction - any direction other than towards an impact with earth is a "good direction". This may of course mean altering its Earth-relative velocity such that while it still intersects our orbit it does so at a point that is out of harms way for now (buys us time)

In between the planets there is very little drag. So you can only alter the course by a few inches. Not much when you are trying to avoid a planet.

The issue is with it rotating 1/2 the time you push it away and 1/2 the time you push it towards. You accomplish nothing. Depending on the size of the rock you could spend a lot of fuel stopping its rotation.

If you don't know orbital dynamics, the best thing to do is either make it go faster or slower. Trying to change the plane takes much more energy. If you make it go faster it gets there before earth does, if you make it go slower then earth goes by before it gets there.

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Push or pull it with Gravity.

Position a mass near it and it's trajectory/orbit will change over time. (actually, the NEO and the altering mass' orbits will change)

This is not a new idea.

Altering the orbit for a rock the size of Central Park might be doable with a couple years notice. Altering the orbit of a Texas-sized iron lump, well...it was nice knowing all of you! :)


Lt

...This is not a new idea.

Altering the orbit for a rock the size of Central Park might be doable with a couple years notice. Altering the orbit of a Texas-sized iron lump, well...it was nice knowing all of you! :)

All may well be "doable" just by the pressure of the sun's light and solar wind by 'merely' deploying large area reflectors on whatever irksome collision-course object.

There's a good report of how an asteroid's orbit was not what was expected unless light pressure was allowed for. There is also the example of the small trajectory change recorded from just the thermal radiation pressure from the uneven heat outflow from the pioneer spacecraft (The Pioneer Anomaly).

We also have a number of probes now that have visited and landed on comets and asteroids...

So... Fly out some space cowboys to lay a few square km of reflective mylar sheet? Or even steer a solar sail craft to deliberately fly onto the rocks/ice to lay out its sail across the surface...

A year or two on station should do the job for even big stuff. The problem more likely would be how to get out there in time despite unfavourable trajectories... Assuming we get to see it coming, and soon enough...


Keep searchin',
Martin

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See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

A small mystery: this morning I had read on www.msnbc.com an article about a big asteroid which should pass at 13 times the Earth-Moon distance on Sunday.I had thought of linking the article here but first I went to www.nasa.jpl.gov seeking confirmation. There was not a line about it. I went back to www.msnbc.com and the article had disappeared.Someone had invented it?
Tullio

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A small mystery: this morning I had read on www.msnbc.com an article about a big asteroid which should pass at 13 times the Earth-Moon distance on Sunday.I had thought of linking the article here but first I went to www.nasa.jpl.gov seeking confirmation. There was not a line about it. I went back to www.msnbc.com and the article had disappeared.Someone had invented it?
Tullio

Here's a link which shows it's today.....

NEO sometime today

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One of the problems that the astronomers that are seeking these planet killers have is that these asteroids only reflect <4% of the light that hits them so they are in effect blacker than coal which if I remember reflect >10% of the light that hits it.As for puting a propulsion system on one some of these not only rotate they also tumble.

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Old enough to know better(but)still young enough not to care