标签：小行星 相关文章
情景对话： Does he really live up there? I took basic astronomy and there was no mention of life, or children, on any other planets. Unless it's true that he came from a star, but that seems improbable. 知识点讲解： There was no mention of
2018年VOA慢速英语(一)月
Why Do Stars Twinkle? If youve ever glanced skyward on a clear evening, youve probably noticed with some wonderment the sheer numbers of stars. Some are tiny, barely visible points. Others radiate strong white light. And from our earthly vantage poin
英语听力文摘 English Digest
By David McAlary Was 16 August 2006 Artist's rendition of solar system There may soon be three new planets in our solar system. The expansion would be the result of a proposed new definition of what a planet is. The change is controversial, but if a
2006年VOA标准英语（八月）
US Astronauts Train in Underwater Lab 美国宇航员在海底实验室接受训练 In the worlds only underwater laboratory, located 19 meters beneath the surface, some five kilometers off Key Largo, four U.S. astronauts prepare to visit an asteroid
VOA标准英语2014年(七月)
Dawn Spacecraft Nears Rendezvous With Dwarf Planet Ceres 黎明号探测器成功将接近谷神星轨道 LOS ANGELES NASAs Dawn spacecraft is set to reach the dwarf planet Ceres in March and begin gathering clues about whether the icy body may have
VOA标准英语2015年(一月)
play pause stop mute unmute max volume 00:0003:20repeat 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. If you think Mars would be a cool place to visit, you ar
CNN美国有线新闻2016年8月
The Space Shuttle Atlantis and its four-person crew landed at the Kennedy Space Center in Florida just before dawn, bringing to a close a program that began in 1981 and leaving the United States temporarily with no vehicle to transport astronauts int
VOA双语新闻 2011年7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
2006年VOA标准英语（七月）
When you consider the Earths history stretching over billions of years, its clear that meteorite impacts, far from being unexpected, are just a normal part of the life cycle of our planet. But that is not how they seem to us. The Chebarkul meteorite
探索与发现2014年
It came in in the daytime sky out of the Sun. Weve got telescopes looking out there for these objects, but they only work at night. Radar doesnt help either because to really use radar to find these objects above the atmosphere, you have to know exac
探索与发现2014年
Approaching from beneath the planet, asteroid 2012 DA14 passed inside the orbit of our geostationary satellites before heading off to the north. This asteroid had been successfully tracked for a year. And despite its proximity, scientists knew that i
探索与发现2014年
Really, its a balance between the size of the object, its speed into the atmosphere and critically the altitude at which it explodes. Too high, if its too small and it explodes too high, the shockwave has little effect on the ground. If its quite low
探索与发现2014年
Oh, perfect, perfect, perfect. Now were seeing the fireball come in, its brighter than the Sun and then, Kapow, it hits the surface. Jeez! This whole region, downrange, would have been incinerated. It would have been incinerated just by this plasma,
探索与发现2014年
But there is a downside to Jupiter. It can also deflect asteroids into orbits that cross the Earths path. The Chelyabinsk meteor appears to be one of these typical Earth-crossing events. The likelihood is that it was thrown out of its regular orbit b
探索与发现2014年
地球是太阳系从内到外的第三颗行星，也是太阳系中直径、质量和密度最大的类地行星。它也经常被称作世界。英语的地球Earth一词来自于古英语及日耳曼语。地球已有44～46亿岁，有一颗天然
英语听力文摘 English Digest
The Time Before Fire What is fire anyway? Well, fire is rapid oxidization . Its the energy released when oxygen atoms start combining with carbon and hydrogen atoms. Exactly, so without oxygen in the air, nothing burns. You mean there was a time befo
英语听力文摘 English Digest
After Messenger's 3 fly-bys, we've now mapped more than 90% of the planet. Taken from around 124 miles, these images are the clearest to date of Mercury. And it's not hard to spot a crater of epic proportions, the result of yet another Titanic collis
自然百科2012年
Vesta 灶神星 You can see the planet Jupiter on a clear night, but Jupiter is humongous. Mars and Mercury are smaller than that, and you can see them, too. Wait a minute, our moon is even smaller, and you can see that. Could anything smaller than t
英语听力文摘 English Digest