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Stardust Probe Enters Comet's Tail Tomorrow
Tortured Potato writes "NASA's Stardust probe is about to pass through the tail of Comet Wild 2 at 11:40am PST, January 2nd. If all goes well, the probe will return the material to earth for research in 2006-- the first extraterrestrial material captured from outside the moon's orbit."
Yes,there WAS a bad sci-fi movie about this. It was called the Andromeda Strain. Based on a book by Micheal Crighton IIRC. Same guy who wrote Jurassic Park. The "probe" brought back a virus that somehow almost escapes into the wild from the containment lab. At the time it was pretty far fetched. but now who knows. It seems Science is not taking nearly as long to catch up to sci-fi as we might think it would.
It's a silicon-based solid with a porous, sponge-like structure in which 99.8 percent of the volume is empty space. By comparison, aerogel is 1,000 times less dense than glass.
The above line, and more, are available here
And yeah, I'd like to play around with some of this stuff as well. The picture of someone holding a 'brick' of it looks like a bad Photoshop job.
I've seen real some aerogel (aerofoam) before. It's difficult to describe, it looks like a solid cloud of gas. It's very fragile, so it probably wouldn't be very useful to build vehicles out of. The best use of aerofoam is as an insulator.
Is it possible to trap helium inside of aerogel? If so, you could have a lighter than air solid. That would be very cool.
This could be very interesting in that there are rumblings that the "tail" of a comet may not actually be melting ice, etc (the dirty snowball model that is the current accepted theory). James McCanney has an interesting theory called the Plasma Discharge Comet Model.
From the website http://www.usinternet.com/users/jmccanney/
"The work showed among other things that comets were not dirty snow balls sublimating (vaporizing) in the solar environment, but were a complex plasma discharge interaction involving an asteroidal comet nucleus with the "solar capacitor", the capacitor being the result of a differential flow in the solar wind of high energy particles leaving the sun. The balance of charge in the solar system and a myriad of of other previously unknown effects were predicted by the theory, including the existence of an electron sheet arriving from the sun at a cometary nucleus and resulting x-rays. Only recently have these been verified by observation. The new comet theory also explained that the tail matter was not moving away from the comet nucleus, but was being drawn in by electrical forces millions of times more powerful than gravity or solar wind forces alone. Essentially a comet was now seen as a huge "cosmic vacuum cleaner". Comets were being captured into the solar system by the existing planets and the comet "tail drag" helped to circularize their orbits. Many commonly stated beliefs regarding the nature of the solar system were being dispelled with more subtle explanations. "
The implications of this theory are intriguing as it may explain how Mars lost its atmosphere as well as such bizarre things as the LaBrea tar pits and all of the trapped creatures in it. (Under this theory a larger body can pull elements from a smaller body if it gets close enough such that things such as oil may not be decomposed dinosaurs, but instead gets "rained" down when a smaller planetary body moves close enough).
Interesting stuff.
The significant problems we face cannot be solved by the same level of thinking that created them. -Albert Einstein
Aerogel is sort of a silicon foam, originally developed on the shuttle, IIRC its the least dense/lightest solid material. Its also nearly transparent if formed right, and is used as an insulation between window panes and i think i heard about a jacket or vest using the material.
"Sic Semper Tyrannosaurus Rex."
Well, the harmfulness to humans of the pathogen was just a side-effect in the andromeda strain (the book isn't terrible, certainly better than the film) - it just happened to "eat" certain polymers, unfortunately including stuff in walls of blood vessels, and was small enough and stable enough (quasi-crystalline) to get in through the lungs. In the book, two humans survive simply because their blood pH is slightly off, so the organism was not supposed to be particularly adapted to attacking earth life. A lot of the book is dry speculation over whether it qualifies as a life form. To date, it's one of the most believable and realistic imaginary aliens.
The end of the book, after a strain has spontaneously mutated in a fortunate manner and outcompeted the original more harmful strain, has a new supersonic plane failing because the pilot's air hose was being eaten through by the strain which had taken to the earth's upper atmosphere. So It wasn't parasitism, the andromeda strain just ate some plastics, including some chemicals necessary to normal functioning of the human body.
What if a probe were sent to a comet to crash into it in such a way that was redirected towards (but not quite directly at) the Earth? The comet might then enter orbit around the Earth and be retrieved with or studied from the space shuttle?
Unknown host pong.
That is such a great movie (not because the movie is "good" in the normal sense, it's good because it's so catastrophically bad and/or plain crazy)
;-). She shaped my adolescent desires in my formative years. Probably why I'm totally screwed up now. But she was incredibly hot in Life Force. No, that's crass. She was absurdly beautiful. And freaky, and prone to making sculptures out of levitating clotted blood for no good reason other than it was a cool special effect at the time that the film producers wanted to show off. But hot. Argh. Dammit. I need a shower.
It's great for one, very important reason:
Ms. Naked Space Vampire - Mathilda May, naked, but only petrified at the start of the film. Really
(If she doesn't look that hot to you in the stills I linked to, that's because you haven't seen her moving, or the close-up of her eyes - now it probably just looks like cheap special effect contacts, but then (1985?), it looked like her eyes were huge dark whirlpools. She looked at the camera and you just stopped thinking.)
Back in 2000 I trained a group of engineers/science type folks at JPL in Pasadena. One of the members of that class was part of the smaple return program that has the goal of returning samples from Mars, several comets, and a some asteroids as well. Stardust is just one of many projects along these lines. Stardust had been launched before I taught the class but one of my co-workers had taught the Stardust group.
The crumple shield concept wouldn't work at the velocitys involved for most of the targets but odds are they considered it, just look at the airbags used for Pathfinder and Beagle2. It could still work for smaller asteroids though.
As to all the talk about pathogens being returned to Earth by these probes, ala "Andromeda Strain", I did ask. There is an department whose ONLY job is to work out how ANY cross contamination can be prevented, they don't want to put terestrial pathogens onto other worlds either.
I still worry about it a little but not as much as I did after that visit.