英语听力：自然百科 行星旅行指南：木星 Jupiter—3

This giant gas bag is built from the flimsiest materials in the universe. But for all its squishy bulk, its a great little mover. Jupiter spins at such a breakneck speed that it bulges at the equator, so fast in fact that a day here lasts less than t

英语听力：自然百科 行星旅行指南：木星 Jupiter—7

If you are floating in a balloon, the center of the red spot might be rather calm. But you will be going fast, your balloon will be going faster than the hurricane winds, but it might be a smooth ride. This storm is a sigh to the halt, towering five

英语听力：自然百科 行星旅行：土星 Saturn—8

Saturns apparently peaceful appearance is due to a haze of high level ammonia in the upper atmosphere, by looking deep into Saturn in the infrared, using the planets own internal heat as a light source, Cassini has revealed the planets true nature. T

英语听力：自然百科 行星旅行：土星 Saturn—10

It was unraveling a puzzle and so the magnetometer team says lets go closer, as we go closer, we watched as the star went through and noticed the change in brightness, something is going on. We can see even from a distance, there seem to be this mate

英语听力：自然百科 行星旅行：土星 Saturn—16

The by-product of billions of years of production from the chemical smog factory in the upper atmosphere, the grains in Titan's dunes may literally fall from the sky. Like a rain of flash-frozen coffee grounds, they are swept by the wind into deep pi

英语听力：自然百科 行星旅行：土星 Saturn—19

The Prime Meridian(本初子午线) here is the longitude, the mark on the ground, from which all great voyages are measured. This is the view back to our remarkable home planet/ that the first human out here can look forward to, a distant blue dot l

英语听力：自然百科 行星旅行指南：木星 Jupiter—19

One day we might develop the magnetic field technology necessary to keep a human alive within Jupiters radiation environment. But in the near future, our exploration will continue by machine. The robotic program isnt about robots. Its a profoundly hu

英语听力：自然百科 行星旅行指南：木星 Jupiter—17

As these robot submarines accomplish great missions, the possibility of one day melting our way into Europas deep ocean is moving from fiction toward fact. Lets just imagine, there were on a little spacecraft with the capability to melt to the ice, w

英语听力：自然百科 行星旅行指南：木星 Jupiter—12

Take a night flight, like Galileos, 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

英语听力：自然百科 行星旅行指南：木星 Jupiter—13

Gas escaping into space from the plumes is energized by Jupiters magnetosphere, creating an intense band of ionizing radiation that bombards a surface already soaked in emissions. If you went out relatively unprotected with, like a normal spacesuit f

英语听力：自然百科 行星旅行指南：木星 Jupiter—14

I would like to visit Jupiter one day，I think it would be a good place to take a vacation, but not on July of 1994. That would have been a terrible time. In July, 1994, the fragmented comet Shoemaker-Levy 9 that David helped / discover began its fa

英语听力：自然百科 行星旅行指南：火星 Mars—5

In the four decades since our robots first arrived, the once fuzzy ball at the end of our telescopes has steadily focused into a red planet we can understand, and it is not a welcoming place. The problem is the atmosphere is so thin and cold that wat

英语听力：自然百科 行星旅行指南：火星 Mars—4

Therere some basic things you should know about Mars before leaving home. Most days will be clear, and sunny and cold. The average temperature on Mars is as bitter as midwinter in Antarctica. And about half the diameter of the earth, Mars is a handy

英语听力：自然百科 行星旅行指南：火星 Mars—1

Have you ever fantasized about going somewhere special? Somewhere far from crowds, off the beaten track. Somewhere out of this world? Is it time to catch a rocket to the Red Planet? Mars is filled with mysteries, Volcanoes 75,000 feet tall, huge cany

英语听力：自然百科 行星旅行：土星 Saturn—1

No planet beats Saturn for jaw-dropping beauty. Saturn is the most photogenic planet in all the solar system. Some of the pictures are to die for. But the postcards only tell part of the story. Beauty is only skin deep. It really is rolling and seeth

英语听力：自然百科 行星旅行指南：火星 Mars—15

If we have been wet, then we want to look for nutrients and food sources that could support microbes. The water ice is proof of a valuable resource for any life forms still clinging(附着) beneath the surface and for future travelers. We now know th

英语听力：自然百科 行星旅行指南：火星 Mars—16

If we are looking for Martian bugs, we should search for life forms at least as tough and alien as this. Im looking at Mars in a point of view of a microbe. And as a microbe, I really need very, very tiny amount of water. I could probably live my ent

英语听力：自然百科 行星旅行指南：火星 Mars—19

So in some ways, a voyage to Mars could be a voyage home. Our ancestors have made such bold trips before when we walked out of Africa, when we sailed over the horizon. If it is technically possible, our ships will head out again. We always want to se

英语听力：自然百科 行星旅行指南：火星 Mars—12

Try the red planet for sight-seeing on an enormous scale. Thanks to our sharp-eyed spacecraft, Mars is opening up like never before. These are real landscapes that humans will one day marvel at in person. You know, if youre going to Mars, youre going

英语听力：自然百科 行星旅行指南：火星 Mars—7

A test run before attempting the fuel hungry and risky trip to the planet below. Dreaming about Mars and actually going there are two very different things. Mars may be our neighbour, but 35 million miles to the closest point is still a very long way