VOA标准英语2011--Juno Spacecraft Launches Toward Jupiter

Juno Spacecraft Launches Toward Jupiter

The U.S. space agency launched the Juno spacecraft from the Kennedy Space Center in Florida Friday, beginning a five-year journey to Jupiter.

"3,2,1. Ignition and liftoff of the Atlas 1 5 [rocket] with Juno on a trek 2 to Jupiter, a planetary piece of the puzzle on the beginning of our solar system," said a NASA commentator 3.

Juno is now on its way toward Jupiter, the largest planet in our solar system. NASA scientists hope this $1.1 billion mission will help them answer some key questions about the way Jupiter - and the solar system - evolved.

Jupiter is believed to have been the first planet to form in our solar system. Juno's eight instruments will study Jupiter's magnetic and gravity fields, as well as the composition of the planet's atmosphere and its core.

Water is a varying factor in many theories about the way planets formed, and, by knowing the amount of water in Jupiter's planetary makeup 4, scientists can rule out some existing theories of planetary evolution.

During the next five years, the solar-powered Juno will spin through space, beyond Mars and the asteroid 5 belt.

Scott Bolton is the principal investigator 6 in the Juno mission. He told reporters at a pre-launch briefing that Juno will spend one year in polar orbit around Jupiter, beginning in 2016. Juno will get closer to Jupiter than any spacecraft before it.

"We're only 5,000 kilometers above the cloud tops, and so we're skimming right over those cloud tops, and we're actually dipping down beneath the radiation belts, which is a very important thing for us because those radiation belts at Jupiter are the most hazardous 7 region in the entire solar system, other than going right to the Sun itself," said Bolton.

The Juno spacecraft has three solar arrays loaded with solar cells. It is the first spacecraft to travel that far on solar, not nuclear, energy.

The Italian Space Agency, as well as partners in Belgium, France and Denmark, contributed components 8 to the Juno craft and instruments.

Juno is also carrying a plaque 9 that pays tribute to the famous Italian astronomer 10, Galileo Galilei, who made important discoveries about Jupiter and its moons in the 17th Century.

Lest you think scientists who study Jupiter are all work and no play, they have placed three pocket-sized Lego figurines on Juno. One represents Galileo, and the figurine even carries a miniature telescope. The other two Lego figurines represent the Roman god Jupiter and goddess Juno. According to mythology 11, Jupiter cloaked himself in clouds to hide his high jinks from Juno, but she was able to clear away the cloud cover to see just what Jupiter was up to - much like the Juno craft is expected to do.