dagblog - Comments for "The sky is falling!"

Thanks. That is really way

EmmaZahn — Fri, 01 Mar 2013 20:26:11 +0000

Thanks. That is really way above my level of comprehension but what little of it I did understand did not seem so unreasonable, assuming reasonableness as a measure of sanity. I mean, the oort cloud itself is only hypothetical. It has never been observed directly and it is not really so much a cloud as a debris field anyway. Why is it unreasonable to suppose that if and when our paths cross that the possibility of impacts would increase?

From my perspective it is just another idea that will be seized on by the OMG! WAGD!* rush seekers and good for a few books and couple of movies of the same genre. Maybe one of them will combine it with Yellowstone erupting since the time cycles look to line up. ;D

Look at it this way: science often needs sciency stuff to keep people interested.

*oh, my god! we're all gonna die!

This is, I think, the

KenArnold — Thu, 28 Feb 2013 22:48:58 +0000

In reply to Thought this from David Brin

This is, I think, the relevant abstract from Monthly Notices of the Royal Astronomical Society. The people who did the research are real astro folks. This doesn't mean they're right, or even marginally sane on this one point. I found this when I was looking to see if any scientific response had been posted (i.e., by some other qualified person). Haven't found one yet.

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2966.2008.13098.x/abst...

I did find it interesting; I

acanuck — Fri, 22 Feb 2013 23:46:26 +0000

In reply to I have no idea who Dick

I did find it interesting; I just disagreed with it.

But here's where it gets confusing: If I click on the words David Brin in your comment, I don't find the quote you cite. If instead I click on the phrase inside the boxed quote itself, "entering a danger zone where molecular clouds might perturb the solar system," that takes me to Pelletier's blog, where it appears as the third paragraph. And Pelletier, like me, doesn't appear to be an astrophysicist.

I have no idea who Dick

EmmaZahn — Thu, 21 Feb 2013 23:11:02 +0000

In reply to Your actual quote is from

I have no idea who Dick Pelletier is. The quote is copy/pasted from David Brin's blog post at Contrary Brin. He is an astrophysicist who writes hard science fiction. The post I linked to began by mentioning that he would be participating as an advisor at the Spring meeting of NASA's NIAC: New and Innovative Advance Concepts. He has also appeared on BBC twice recently to answer questions about the Russian meteorite. I have no idea how seriously he credits Napier and Janaki's work but at least enough to pass it along as an FYI item. I followed suit thinking you might be interested.

Your actual quote is from

acanuck — Thu, 21 Feb 2013 21:28:41 +0000

In reply to Thought this from David Brin

Your actual quote is from Dick Pelletier's blog, which I give little credence to. The rocks that hit or graze Earth come from our solar system's asteroid belt. Is he suggesting that every 37 million years or so, the system passes through molecular clouds that will knock 10 times as many asteroids out of their orbits? Those clouds are not stationary things we collide with; they revolve around the galactic center at basically the same speed as our sun does. I have trouble seeing how a gradual thickening of the interstellar medium is going to have such a whopping gravitational effect. The second threat he cites is even less credible, at least to me.

Thought this from David Brin

EmmaZahn — Wed, 20 Feb 2013 22:21:17 +0000

In reply to The sky is falling!

Thought this from David Brin today might interest you.

Professor William Napier and Dr. Janaki Wickramasinghe have completed computer simulations of our sun’s movements in its outer spiral location in the Milky Way, and determined that we are now entering a danger zone where molecular clouds might perturb the solar system -- the odds of asteroid impact on Earth go up by a factor of ten.

Thanks for the read. The

trkingmomoe — Sat, 16 Feb 2013 22:34:31 +0000

In reply to Canadians to the rescue yet

Thanks for the read. The picture of the little satellite is interesting. I wonder how long something that small can stay in orbit until it needs replaced. They didn't say anything about it's life span only it is a night and day 24 hour operation. I know NASA has been wanting to map all the asteroid belts deep in space. This is going to keep a eye on closer stuff and all the junk we have dumped up there. But it is still a great achievement because it don't take a large rocket to launch it.

A pinprick compared to the

Aaron Carine — Sat, 16 Feb 2013 21:58:10 +0000

In reply to The sky is falling!

A pinprick compared to the Tunguska explosion, but still scary. But I take comfort in knowing that no meteorite larger than a baseball has ever hit a city.

For sure the little one would

EmmaZahn — Sat, 16 Feb 2013 20:37:12 +0000

In reply to Given their relatively tiny

For sure the little one would have been annihilated by the collision but not so sure about the big one. And what are the odds of two completely unrelated asteroids showing up the same day, eh?

I did wonder if maybe the opposite directions was a result of the little one getting caught by earth's gravity and slung around. Could they have been companions before that, the little one scouting for the big one. ;) Twitter was all abuzz wondering who or what may crawl out of that lake in Siberia.

Guess I will just have to keep reading. What a chore :D

Canadians to the rescue yet

acanuck — Sat, 16 Feb 2013 18:44:15 +0000

In reply to NASA has wanted for years to

Canadians to the rescue yet again:

http://www.asc-csa.gc.ca/eng/satellites/neossat/

Considering that it's said to be such an improvement over existing detection systems, this telescope is amazingly small. Its lens or mirror (I'm not sure which it has) is just 15 cm (six inches), comparable to many backyard telescopes.