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Re: The Astronomy Thread

Posted: Sun Feb 17, 2013 1:55 am
by fredgiblet
Does it still count as astronomy when it's in the atmosphere?

Re: The Astronomy Thread

Posted: Sun Feb 17, 2013 3:57 am
by Trantor
fredgiblet wrote:Does it still count as astronomy when it's in the atmosphere?
Came from outside, was captured from above, too - so i dare to say yes:

Image

Re: The Astronomy Thread

Posted: Sun Feb 17, 2013 4:39 am
by Absalom
Between this and Tunguska, I'm not certain whether to think meteoroids love Russia, or hate it. :lol:

Re: The Astronomy Thread

Posted: Mon Feb 18, 2013 2:21 am
by Fotiadis_110
amusingly, we've discovered that actual meteorites are fairly common :p

And that a couple decent ones touch down every year, however most cities are small compared to the surrounding terrain. As our world becomes more urban, expect more meteorite stories,

Re: The Astronomy Thread

Posted: Mon Feb 18, 2013 3:08 pm
by GeoModder
It came down a bit late for the centennial celebration of Tunguska. :|

Re: The Astronomy Thread

Posted: Mon Feb 18, 2013 6:01 pm
by Alexandr Koori
And all forgot about Sikhote-Alin meteorite.
Yes, we loves meteorites and meteorites loves us)

Re: The Astronomy Thread

Posted: Mon Feb 18, 2013 7:19 pm
by GeoModder
Can you blame us? It was in the middle of the Cold War! :P

Re: The Astronomy Thread

Posted: Wed Feb 20, 2013 12:39 am
by Karst45
I like how they put some of the "hell door" picture and claimed it was that meteorite that did it... when we all know (after i tell you) it actually a minin operation gone wrong 40 year ago (more or less)

Re: The Astronomy Thread

Posted: Sun Mar 03, 2013 6:46 am
by Trantor
Next one:

http://en.wikipedia.org/wiki/C/2013_A1

Oh please please please, let us see THAT spectacle!

Re: The Astronomy Thread

Posted: Sun Mar 03, 2013 6:59 am
by Arioch
The closest estimates still have the comet passing more than 40,000 km from the centerpoint of Mars; since the diameter of Mars is less than 7,000 km, that doesn't sound like it's going to get the job done.

Re: The Astronomy Thread

Posted: Sun Mar 03, 2013 8:44 pm
by GeoModder
Oh boy, if the comet would be at the upper limit of its size, and if an impact would happen, good-bye to plans of colonising Mars. :o

But at 0.08% chance, I don't see it happen.

Re: The Astronomy Thread

Posted: Mon Mar 04, 2013 8:28 am
by fredgiblet
If it's smaller and hits it might help terraforming.

Re: The Astronomy Thread

Posted: Mon Mar 04, 2013 4:49 pm
by GeoModder
fredgiblet wrote:If it's smaller and hits it might help terraforming.
By making the planet surface even frostier?

Re: The Astronomy Thread

Posted: Mon Mar 04, 2013 6:26 pm
by fredgiblet
Adding water.

Re: The Astronomy Thread

Posted: Tue Mar 05, 2013 6:36 pm
by GeoModder
Which sublimes right into space again over time, until the atmosphere gets denser. :shrugs:

Re: The Astronomy Thread

Posted: Fri Mar 08, 2013 10:55 pm
by discord
which sublimes into a denser atmosphere, that will in turn would be blown away by solar radiation....something that would take a few centuries or millennium, during which time there would be more atmosphere to work with.

Re: The Astronomy Thread

Posted: Sat Mar 09, 2013 1:50 am
by Yiuel
Instant Biosphere, just add water?

It will take more than a mere comet to terraform or even start the terraforming of Mars. There are reasons why Mars has no viable biosphere for us, and the lack (or non-lack) of comets does not seem one.

Re: The Astronomy Thread

Posted: Sat Mar 09, 2013 12:14 pm
by GeoModder
Yiuel wrote:It will take more than a mere comet to terraform or even start the terraforming of Mars. There are reasons why Mars has no viable biosphere for us, and the lack (or non-lack) of comets does not seem one.
This.

Re: The Astronomy Thread

Posted: Sun Mar 10, 2013 11:32 am
by discord
never said instant terraforming, but with a little luck you get a hell of a lot of water vapor in the 'air', and impact should throw alot more stuff up an hopefully keep more solar heat on planet, heat is good....

but this is still 'with some luck' and even then only a beginning, would take lots of work(probably centuries) to get it done, this would just cut a few years maybe a decade of the work.... the big problem for long term sustainability is actually the lack of magnetic shielding to keep solar winds from blowing away the atmosphere(subliming gets it high, solar wind blows it away).

only way i can think of would be to gather up a few...million tons of radioactive stuffs, dig out the 'core' and seed it with a molten core. that should create a magnetic field, just like earth's got.

sublimation of the atmosphere would probably still be an issue, but then it would be a matter of several thousand years instead of hundreds. basically it would be a ongoing struggle to keep the atmosphere, but it IS doable, just....on a insanely large scale.

Re: The Astronomy Thread

Posted: Mon Mar 11, 2013 8:10 am
by Absalom
I won't pretend that it'll be practical for centuries (or more... in fact, I'll actually say "within the lifespan of the sun"), but producing an actual working fluid magnetic core should be quite possible. What you basically want to do is find some frequency that will pass most of the way through the planet (I assume that a skin depth of 2/3 the planetary diameter would be ideal, but I have no idea what the frequency would be, other than "insanely low"), but not all of the way ("not all of the way" being, of course, the easy part: the good news is that research has succeeded in making aluminum transparent to certain wavelengths when exposed to sufficient strengths of other wavelength: the bad news is that it was a very small spot, vs a very powerful pulse). Then you "just" take several em emitters of the correct frequency range (ha! good luck with that one!) & power, place them in orbit, and turn them on. The higher the output, the faster you get results. After that you "just" use massive-scale explosive arrays to knock chunks off of the inner crust (Mars' crust is apparently twice as thick as Earth's) and you should have the conditions for a vibrant-ish planetary core. I assume that you'd then want to increase the mass of the planet at the same time as you added water. That will obscure all existing features, of course, but if you do it by grinding your meteoroids/asteroids into a powder, and throwing THAT into the atmosphere, then you should be able to prevent the features from actually being destroyed.

The real problem is making certain that you get Earth-like tectonics (sliding plates) instead of Venusian tectonics (which apparently involve having massive slabs fall into the mantle, producing island-or-larger size lava zones). After all, "no tectonics" is better than "oh so massively the wrong tectonics".