标签：asteroid 相关文章
Grandfathers eyebrows raised in surprise as he watched his grandchildren and Rachel Cunningham climb onto the stage. They stood beside the podium. I hope this interruption is important, James Alden said. Its about Marks paper, Henry said. Mark sat up
59 The Outer Space Mystery
The surface of Mars is etched with ancient river valleys and lake basins. Which makes researchers think that liquid water once flowed on the Red Planet. But how? Today, Mars is too cold for much, if any, liquid water to exist. And 3.8 billion years a
2017年Scientific American(一)月
Dame Ellen MacArthur (born in 1976) is a very brave and talented English yachtswoman. Her first name is Ellen; Dame is a special title she received for her outstanding achievements from the British Queen. On 7 February 2005, she broke the world recor
各国名人英文介绍
Today's topic is further versus farther. Almost every week someone asks me to explain the difference between further and farther. Three years ago when I was on the Oprah Winfrey Show, a production assistant grabbed me backstage while my head was stil
英语语法 Grammar Girl
Halfway there, you bump into the Asteroid Belt. It is not like in the movies where you are dodging asteroids at every second. It is a The space is very big and the asteroids are a long distance apart, so you could travel through it quite safely. The
自然百科2012年
By Patricia Nunan in Kantale, Sri Lanka 24 August 2006 As many as 170,000 people in northern and eastern Sri Lanka have been displaced in recent weeks by fighting between the Tamil Tiger rebels and government forces. VOA's Patricia Nunan recently me
2006年VOA标准英语（八月）
Space Shuttle's End Prompts Doubts About NASA's Future One day after the landing of Atlantis ended the 30-year space shuttle program, the company that ran shuttle operations for the U.S. space agency NASA is dismissing 1,510 employees. The end of the
VOA标准英语2011年(七月)
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)
Study: Immune System Weakens in Space During the final flight of the US space shuttle Atlantis in the summer of 2011, one of the most important pieces of scientific cargo on board was a medical experiment designed to test how the human immune system
VOA标准英语2013年(四月)
SHEREEN MARISOL MERAJI, HOST: Artists reflecting on the current political climate are taking their ideas to the streets. For one national project, some artists are making billboards about different social issues. NPR's Mandalit del Barco talked with
2018年NPR美国国家公共电台10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
Imagine boarding a flight to Saturn, what would you need to know before traveling? The best ringside vantage points? The must-see moons? Think of this as your personal guide to the splendor of the Saturnian system. A wandering spot of light twice as
自然百科2012年
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
There it is! Yep. Its about 90 kilometres up, at that stage, travelling at 17.5 kilometres per second. Using the different camera positions, scientists have pinpointed the exact position at which the meteor entered the atmosphere. And by tracking the
探索与发现2014年
Most of the damage from an explosion like this is actually the blast wave. Its the very high winds. Mark created a simulation to see what size an asteroid would need to be to be able to generate such destructive power. In this simulation I include mo
探索与发现2014年
So this was serial number one. It was built during the Apollo time. I guess because they thought there would be several of them made, but this is the first one and the last one and is the only one like it in the world. This is NASAs Vertical Gun Rang
探索与发现2014年
On 6th October 2008, asteroid hunter Richard Kowalski saw something that would change the assessment of threats presented by asteroid impacts. The night was proceeding normally and up on the screen came another asteroid. As I continued to make observ
探索与发现2014年
Meteor strikes as big as this may be rare butscientists have a surprisingly detailed knowledge of what meteorites are andwhere they come from. Long before the meteorite reached its explosivefinale in full view of Chelyabinsks dash cams, it had a very
探索与发现2014年