What, there's no Saturn gas on eBay?
March 7, 2010 2:49 PM   Subscribe

What can an 11 year old use (safely) as a sample of gas from Saturn?

She and her classmate have returned from a visit to Saturn and will be doing a presentation about their trip. They have their spiel down pretty well, but she asked if it was possible to get dry ice in a test tube to show the class, as a sample of gas from the rings.

After googling, I've decided that the threat of a nasty accident kinda rules out dry ice, but couldn't find any suggestions for an appropriate substitute.

What can we use instead? The 'gas' must be visible. Odour is irrelevant, unless we can easily get something utterly non-toxic (but unrecognisable) that the kids could smell.

Oh, and we live in a small country town - the less exotic the ingredients, the better.

PS: We have a crystal making kit, with aluminium potassium sulphates mixed with food dye, and monoammonium phosphates mixed with food dye. Any chance we could use those somehow?
posted by malibustacey9999 to Science & Nature (12 answers total)
 
Best answer: Dry ice is simpy solid carbon dioxide, so I doubt you would be able to keep the gas visible for very long anyway. So instead I would suggest mixing up all sorts of powders and colors from your crystal kit to make samples of "dust particles" from the rings - which are mostly orbiting clumps of ice and rocks and lots of dust (from ice and rocks smashing into each other) anyway. Gas is more likely to come from the planet itself.
posted by casarkos at 3:05 PM on March 7, 2010


You could have water and dirt in it -- as the (now melted) ice and dust particles.
posted by jb at 3:12 PM on March 7, 2010


Large clear plastic container with small amount of talcum powder. Shake well before distributing.
posted by dontjumplarry at 3:45 PM on March 7, 2010


I don't think you'll be able to make any safe colored gas. But maybe you can fake it by dyeing the inside of a container to look like the gas inside is colored. Glass won't take a dye, but perhaps plastic one like a peanut butter jar? I'd start with maybe a RIT dye or something else that might dye plastic.
posted by DU at 4:09 PM on March 7, 2010


Iodine gas is very distintly colored, but it's not 100% non toxic. As for smelly gasses there's Methanethiol which is the gas that's added to natural gas to allow people to smell leaks.
posted by borkencode at 4:40 PM on March 7, 2010


When you come to a decision about the chemicals to use from the answers here on MeFi, you may want to run it by the science teacher first. I wasn't aware that our local high school had a list of chemicals/other items that you could not bring onto school grounds (probably from bad past experience from ubdding scientists) until I tried to help a friend's kid with a science project...there was a long list of banned items.
posted by MsKim at 8:05 PM on March 7, 2010


A helium balloon for gas from the planet (hydrogen & helium), and a container of melting ice for the rings.
posted by zamboni at 8:44 PM on March 7, 2010


They do sell portable generators that use the same solution as commercial fog machines - specifically the "Wizard Stick." I really don't think the safe, non-toxic, DIY chemical smoke you're looking for is out there (certainly not safer than fully and reliably vented container with dry ice and water in it) Very much second checking anything with the teacher beforehand including the dry ice if you reconsidered that.
posted by nanojath at 8:46 PM on March 7, 2010


There are not a lot of visible gasses out there. Some things have a slight color to them, but you'd barely notice them in a test tube or small bottle.

The thing about dry is is that it becomes non-ice pretty quickly and will cheerfully blow the stopper (or explode the container) in which it's stored. The thing that gives you that foggy look around dry ice is the water in the air condensing.

I think something along the lines of what jb suggests might be the best plan - show some of the components that make up the rings as your samples, but point out that many of them are liquids and gasses here on earth.
posted by Kid Charlemagne at 9:24 PM on March 7, 2010


Hm. Wikipedia says that the rings are mostly water ice— “93 percent water ice with a smattering of tholin impurities, and 7 percent amorphous carbon”. Tholins aren't stable in air, but you could approximate this maybe with water, plus enough benzene or other hydrocarbon to be able to smell it, and enough lampblack to be able to see it (and/or to make up 7%).

If she visited any of the moons, it seems Titan is thought to have some ammonia-water-mixture layers, which would be easy to acquire a "sample" of (household ammonia solution), not terribly toxic, and it would be distinguishable from water (unstopper the test tube and the smell will be immediately perceptible). I don't remember what the current thinking on hydrocarbon lakes / rain / wax snow are on Titan, but that's another possibility.

Methane, unfortunately, is colorless and odorless, so wouldn't be very interesting to bring. Ditto hydrogen. I'm guessing that kids aren't allowed to light off tubes full of hydrogen in class either, which is too bad because it's a nifty demo.

Dry ice isn't too dangerous if treated with respect; just remember that (a) it will expand, so don't confine it in a sealed container and (b) it's cold enough to give you a nasty burn if it actually freezes to your skin, but sublimates rapidly enough when you touch it to be deceptive. Fishmongers deal with it all day after all.
posted by hattifattener at 10:59 PM on March 7, 2010


I'm curious about what kinds of nasty accidents you fear from dry ice. I'd suggest a five-gallon pickle bucket filled about 3/4 with hot water. Put it on the table with their other visual aids, then as part of the spiel they can talk about how they've brought some concentrated "Saturn gas" back with them. Drop a 1-pound chunk of dry ice into the bucket [holding it with a winter glove] and they'll get some billowing "smoke" rolling over the edge of the bucket for a while. The kids will think it's cool, then maybe your presenters can talk about how really, Saturn is made of of other gases like the gas in this helium balloon over here.

I've used dry ice in a bucket at a whole bunch of my kids' halloween parties and you get a nifty short-lived fog roiling along the floor from it. Sure, you want to use gloves, and you don't want to confine it [I used to explode bottles that way in high school for fun], but it seems to me to one of the least dangerous "chemicals" you could bring into the classroom.
posted by chazlarson at 8:43 AM on March 8, 2010


You could buy a misting fountain (random Google results)?
posted by lioness at 2:00 PM on March 8, 2010


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