官方APP下载:英语学习播客(支持苹果手机、安卓手机)
创办于2003年
UNSV记不住?那就记中文谐音“忧安思危”吧!
  Slow and Steady Wins the Race!
UNSV英语学习频道 - Slow and steady wins the race!
公众微信服务号(英语全能特训)
英语全能特训(微信公众服务号)
UNSV英语学习频道淘宝网店
客服短信:18913948480
客服邮箱:web@unsv.com
初级VIP会员
全站英语学习资料下载。
¥98元/12个月

NASA to Return to Venus with Two New Missions

作者:Bryan Lynn 发布日期:6-7-2021

The U.S. space agency NASA has announced plans to launch two new missions to the planet Venus.

The missions will mark a return to U.S. exploration of Venus after many years. Two new robotic spacecraft are to be designed and built to study the planet with the highest temperatures in our solar system.

NASA chose American company Lockheed Martin to create and operate both spacecraft. The company will receive $500 million for each mission through NASA's Discovery Program. The spacecraft are expected to launch between 2028 and 2030.

One mission, called DAVINCI+, is designed to measure the planet's dense, cloudy atmosphere to understand how it formed and developed, a NASA statement said. It also aims to capture the first high-quality pictures of geological structures on Venus. Some are similar to ones on Earth.

After arriving at Venus, the DAVINCI+ spacecraft will send a probe into the planet's atmosphere. It will then use its instruments to measure levels of gases and other elements, temperature and pressure, Lockheed Martin said.

The other mission, VERITAS, will map the surface of Venus to learn about "the planet's geologic history and understand why it developed so differently than Earth," NASA said. When the VERITAS orbiter arrives at Venus, it will use a method called "aerobraking" to place itself "into an optimal science position in the planet's orbit," Lockheed Martin said. It will then use imaging equipment to capture data about the planet's geology.

Venus is Earth's closest planetary neighbor and the second closest planet to the sun. It is similar in structure to Earth, but a little smaller. Venus rotates in the opposite direction as Earth and most other planets. Also, its rotation is very slow.

The air on Venus is so dense and pressurized that it behaves more like a fluid than a gas near the surface. The planet has extremely high winds that push clouds completely around the planet every five days.

Such extreme conditions make it difficult for spacecraft to survive in Venus' atmosphere or on its surface. But scientists are very interested in learning more. Some believe Venus may have had ancient seas that could have made it habitable before unknown forces destroyed them.

"It is astounding how little we know about Venus," NASA scientist Tom Wagner said in a statement. He added that the new missions can provide fresh data on the planet's thick atmosphere, which is made up mostly of carbon dioxide. "It will be as if we have rediscovered the planet," Wagner said.

James Garvin is the chief scientist for NASA's Goddard Space Flight Center in Maryland. He said in a statement he considers Venus important to understanding "climate change, the evolution of habitability and what happens when a planet loses a long period of surface oceans."

The first spacecraft to explore Venus was NASA's Mariner 2 in 1962. It passed within about 34,000 kilometers of the planet. NASA says Mariner 2 successfully recorded the planet's temperature for the first time. It measured the Venus surface temperature to be about 465 degrees Celsius.

The United States and the former Soviet Union sent several spacecraft to Venus from the 1960s to the 1980s. The former Soviet Union is the first and only country to successfully land a spacecraft on the surface of Venus. The first landing was the Soviet explorer Venera 7 in 1970. The Soviet spacecraft lasted less than two hours in the extreme environment.

In 1989, NASA used a space shuttle to send its Magellan spacecraft into orbit around Venus. The European Space Agency also put a spacecraft into orbit around Venus in 2006. And, a Japanese spacecraft called Akatsuki was launched in 2010 and is currently orbiting Venus.

I'm Bryan Lynn.

Bryan Lynn wrote this story for VOA Learning English, based on reports from NASA, The Associated Press, Reuters and Lockheed Martin. Mario Ritter, Jr. was the editor.

We want to hear from you. Write to us in the Comments section, and visit our Facebook page.

_________________________________________________________________

Words in This Story

missionadj. a flight by an aircraft or spacecraft to perform a specific task

geologyn. the study of rocks and soil and the physical structure of the Earth

proben. a vehicle used to examine or observe something closely

optimaladj. the best of most effective possible in a particular situation

rotatev. to turn or cause something to turn in a circle

habitableadj. able to support life

astoundv. to surprise of shock someone very much

evolutionn. a gradual process of change and development

版权所有©2003-2019 南京通享科技有限公司,保留所有权利。未经书面许可,严禁转载本站内容,违者追究法律责任。 互联网经营ICP证:苏B2-20120186
网站备案:苏公网安备 32010202011039号苏ICP备05000269号-1中国工业和信息化部网站备案查询
广播台