Why don't astronauts sublimate in space?
I'm a High Schooler who is very interested in science, especially physics. After taking several science classes last year I've spent much of the summer wondering and pondering certain topics which were covered in class. I can't wait any longer to find a teacher who can answer my questions so I thought you might be able to help.
The question is why do astronauts and the space shuttle not boil away(or sublimate) as they travel out of the earth's atmosphere?
Here are the facts(or false information) that have me stumped concerning this seemingly foolish question.
Boiling point is defined as the temperature at which the vapor pressure equals the atmospheric pressure. The atmospheric pressure in space would have to be zero.
It would seem that as the space shuttle traveled through the steadily decreasing atmospheric pressure it would reach the point at which the metal of the ship would sublimate, and then the astronauts would also sublimate. A phase diagram would help me in explaining my confusion but you'll have to imagine that one.
I can't figure out where the error in my logic is. Please help.
I can see where the confusion comes from and it certainly seems reasonable enough to make this conclusion! It is certainly true that there are no liquids in space and that if the liquid form of the metal that the Shuttle is made from went into Space it would boil very quickly. The difference is that the Shuttle and the Astronauts are solid objects. In order for them to sublimate, then there needs to be enough energy incident on them to break the strong bonds making the solid. This can be true for some solids in some conditions (for example it happens to comets as they near the Sun) but not in the case of the shuttle or the Astronauts' space suits.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.
This page has been accessed 18733 times since November 23, 2002.
Last modified: November 23, 2002 5:35:15 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)