英语听力:自然百科 行星旅行指南:木星 Jupiter—12(在线收听) |
Take a night flight, like Galileo’s, over the surface of Io and the view down to the churning lava lakes would be unforgettable. Imagine then a visit to the surface. The landscape might look quite a bit like a red and yellow sulfur-painted version of what you would see if you went to the big island of Hawaii. With the interesting additions of the effect, you have a very low gravity field. And these geyser(s) are like eruptions of sulfur dioxide gas which give you a kind of spray of condensing sulfur dioxide crystals rising up in 100 kilometer height umbrella-shaped foams and falling back down to the surface.
Giant plumes are snowfall of sulfur, fire fountains of lava, some even hotter than lava on Earth. Just why is Io cooking inside?
The reason for Io’s tremendous volcanic activity is energy that’s being pumped into it from the tides raised by Jupiter. Not talking about liquid tides like out here in the ocean, I’m talking about the whole body of Io is being squeezed by tidal forces. So every day, the surface/of Io at the equator when it’s / closest to Jupiter would be maybe 100 meter higher than it is when it’s furthest from Jupiter. That’s an awful lot of squeezing and pushing.
Io is like warm putty in Jupiter’s gravitational hand. Adventure travelers? Take note: a trip out here comes with some pretty hefty health warnings.
Io's got a very, very tenuous atmosphere, mostly of the gases that are coming out of volcanoes. And so it wouldn’t be a very nice place, basically no air to breathe. It probably would look very beautiful if you could get away from the discomfort of sitting there, minus 300 degrees Fahrenheit having to protect yourself from that and also being given a pretty hefty dose of radiation that would be lethal. |
原文地址:http://www.tingroom.com/lesson/zrbaike/2012/273942.html |