Could we live on Jupiter?

From the moon to Mars, scientists have been looking for water—the key to life—in the solar system (太阳系) for decades. Recently, they have turned to Jupiter (木星)!

On April 14, the European Space Agency’s (ESA) JUICE spacecraft (航天器) successfully lifted off from French Guiana in South America. JUICE, short for “Jupiter Icy Moons Explorer”, will collect data from Jupiter and its three moons, Europa, Ganymede and Callisto.

The three moons are believed to have big oceans of liquid water (液态水) under their icy shells (壳). According to ESA, the water on those moons could be as much as six times the amount in Earth’s oceans. The mission “will change our understanding of the solar system”, wrote Scientific American.

In 1998, NASA’s Galileo spacecraft found that Europa might be ejecting (喷射) water as far as 160 kilometers into space. That gave scientists the idea of studying the icy moons of Jupiter.

The oceans under these moons are likely to be tens of kilometers deep. But they are also trapped under tens of kilometers of ice, making it very difficult to study them. Although JUICE cannot land on the surface, it has lots of high-tech equipment to study the moon’s environment, including spectral imaging (光谱成像) tools and radar (雷达). They could give more data on things like the thickness (厚度) of the oceans, their salt content (含量), and their distance from the icy shells above, reported Phys.org.

“The main goal is to understand whether there are habitable (可居住的) environments among those icy moons and around a giant planet like Jupiter,” JUICE team member Olivier Witasse said during a press conference (发布会) on April 6.

There is a new sight in the sky these days —the newly-discovered Comet (彗星) NEOWISE is flying past the sun. This the first time since the 1990s when people have had a chance to see a comet with their bare eyes (裸眼).

A comet is basically a ball of dirty ice that moves around the sun. As a comet comes close to the sum, the sun melts some of the ice, which makes a tail behind the comet as it flies through space. Most comets move around the sun in a circle. Comets spend most of their time moving slowly, far away from the sun. As they pass the sun, they speed up.

The size and shape of a comets moving way can influence how long it takes to finish its one circle. Halley’s Comet is a famous comet coming around once every 75-76 years. But the last time Comet NEOWISE was here near the sun was about 6, 800 years ago. Because of the long time it takes to finish its one circle, NEO WISE was only just discovered some months ago. It was seen in March with a special space telescope run by NASA.

The name of the telescope system that first saw the comet is NEOWISE, so that’s how the comet got its name. NEOWISE is easy to see now because it is close to the sun. At its farthest, NEO WISE will be 630 times farther away from the sun than the earth is.

Even at its closest—which was on July 23 —the comet was still as far away from the earth as Mars was. But it was still bright enough to see, even without a telescope.

If someone asks you, “【小题1】” I think you will answer “Blue”. I’m afraid that you will be wrong. 【小题2】 It looks blue because we are looking at the blue sunlight. The sunlight is shining on little bits of dust (灰尘) in the air.

【小题3】 I’m sure that you have asked this question, too. We know that there is air all around the world, but we couldn’t fly very high because as we go high, the air gets thinner. If we go far enough away from the Earth, we find there is no air.

Maybe we can answer some questions now. What is the sky? Where is it? It is all around the world. 【小题4】 In space, there is nothing, but only the Sun, the Moon, the Earth and all the other stars.