This is Scientific American's 60-Second Science. I'm Karen Hopkin. Thisll just take a minute. Any school kid can tell you that comets are made of ice. That frozen water burning off is what gives comets their characteristic tails. But asteroids were g

发表于:2018-12-02 / 阅读(74) / 评论(0) 分类 Scientific American(四)月

04 美国的航空航天技术 DATE=2-21-01 TITLE=EXPLORATIONS #1940 - Space Digest BYLINE=Paul Thompson VOICE ONE: This is Steve Ember. VOICE TWO: And this is Shirley Griffith with the VOA Special En

发表于:2018-12-07 / 阅读(71) / 评论(0) 分类 科技之光

Broadcast: Jan 29, 2003 By Paul Thompson VOICE ONE: This is Mary Tillotson. VOICE TWO: And this is Steve Ember with the VOA Special English program EXPLORATIONS. Today we tell about a space rock that

发表于:2018-12-07 / 阅读(68) / 评论(0) 分类 VOA2003(上)-科技导航

This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute. If we want to learn more about our planet and other planets in the universe, we can get some help from stars that are long dead and gone. Thats what U.

发表于:2019-01-08 / 阅读(79) / 评论(0) 分类 Scientific American(一)月

LOS ANGELES, Aug. 20 (Xinhua) -- Walt Disney Studios Saturday disclosed the ongoing production of two new movies, included one directed by Academy Award winner Pete Docter. The studio made the revelation at the D23 Expo, the Disney version of Comic-C

发表于:2019-01-11 / 阅读(99) / 评论(0) 分类 英语新闻

LOS ANGELES, April 8 (Xinhua) -- NASA's Wide-field Infrared Survey Explorer (WISE) has discovered a rare asteroid that traces out a horseshoe shape relative to Earth, the Jet Propulsion Laboratory (JPL) said on Friday. Unlike most near-Earth asteroid

发表于:2019-01-11 / 阅读(80) / 评论(0) 分类 英语新闻

NASA: Humans Could Visit Asteroid in 2021 These chunks of ancient space rocks hold clues about the formation of the universe, pose threats to our planet, and present new territory for explorers. NASA's proposed asteroid mission is a logical next leap

发表于:2019-01-14 / 阅读(67) / 评论(0) 分类 VOA标准英语2013年(六月)

ARI SHAPIRO, HOST: A giant asteroid slammed into Earth about 65 million years ago. That impact killed off the dinosaurs. And now scientists say it had another major effect on the planet, one that's a cautionary tale. Here's NPR's Nell Greenfieldboyce

发表于:2019-01-16 / 阅读(77) / 评论(0) 分类 2018年NPR美国国家公共电台5月

NASA Launches Mission To Retrieve Ancient Asteroid Dust play pause stop mute unmute max volume 00:0003:12repeat repeat off Update Required To play the media you will need to either update your browser to a recent version or update your Flash plugin.

发表于:2019-01-16 / 阅读(85) / 评论(0) 分类 2016年NPR美国国家公共电台9月

NASA's Other Asteroid Mission: Grab A Chunk And Put It In Orbit Around The Moon play pause stop mute unmute max volume 00:0004:02repeat repeat off Update Required To play the media you will need to either update your browser to a recent version or up

发表于:2019-01-16 / 阅读(108) / 评论(0) 分类 2016年NPR美国国家公共电台9月

LOS ANGELES, June 24 (Xinhua) -- Near-Earth asteroid 2011 MD will whip past Earth on June 27, but will not pose any threat, NASA's Jet Propulsion Laboratory (JPL) said on Friday. The asteroid will pass only 12,000 kilometers (7,500 miles) above the E

发表于:2019-01-20 / 阅读(100) / 评论(0) 分类 英语新闻

By Paul Sisco Washington, DC 07 July 2006 watch Asteroid report A major asteroid passed by the Earth this week, and another is heading this way. An asteroid visible in the night sky Asteroids are similar to comets and meteors. But they are larger, m

发表于:2019-01-20 / 阅读(142) / 评论(0) 分类 2006年VOA标准英语(七月)

By Mike O'Sullivan Los Angeles 03 July 2006 A large asteroid, known as 2004 XP14, raced past the Earth early Monday. Scientists say it posed no threat to the planet, but serves as a reminder of the hazards encountered in space. -------- The rocky sp

发表于:2019-01-20 / 阅读(130) / 评论(0) 分类 2006年VOA标准英语(七月)

BEIJING, Nov. 7 (Xinhuanet) -- A huge asteroid will pass closer to Earth than the moon on Tuesday, but experts say there is no cause for alarm. Asteroid 2005 YU 55 will pass about 300-thousand kilometers from the earth. The giant space rock is about

发表于:2019-02-08 / 阅读(75) / 评论(0) 分类 英语新闻

BEIJING, June 28 (Xinhuanet) -- A truck-sized asteroid passed over the Atlantic Ocean within 7,500 miles of the Earth on Monday, according to NASA's Jet Propulsion Laboratory. The space rock, called asteroid 2011 MD, is the second space rock to zip e

发表于:2019-02-15 / 阅读(79) / 评论(0) 分类 英语新闻

Science and technology 科学技术 Dealing with asteroid strikes 应对小行星撞击 A close shave 近地掠过 After a hit and a near miss minds are focusing on the risks from space rocks 在一次撞击和一次近距离擦肩而过后,人们开

发表于:2019-02-18 / 阅读(96) / 评论(0) 分类 经济学人科技系列

NASA has announced that an Asteroid will pass closer to Earth than the TV satellites that surround the planet. NASA says that the celestial visitor has no chance of impacting the Earth and is known as 2012 DA14. A group of amatuer astronomers discove

发表于:2019-02-21 / 阅读(82) / 评论(0) 分类 英闻天下

Meanwhile, a 45-meter wide asteroid has hurtled safely past earth after it came within 27-thousand kilometers, making it the closest known flyby for a rock of its size. The asteroid, named 2012 DA14 came closer to earth than many communication and we

发表于:2019-02-21 / 阅读(72) / 评论(0) 分类 英闻天下

By the early 1900s, it had often become impossible to know whether an asteroid that popped into view was new 到20世纪初,往往分不清哪颗小行星是刚刚出现的, or simply one that had been noted earlier and then lost track of. 哪颗小

发表于:2019-02-25 / 阅读(70) / 评论(0) 分类 万物简史

1. In Democracies and its Critics, Robert Dahl defends both democratic value and pluralist democracies, or polyarchies. Dahl argues convincingly that the idea of democracy rests on political equalitythe equality capacity of all citizens to determine

发表于:2019-02-25 / 阅读(127) / 评论(0) 分类 GRE英语