标签：陨石 相关文章
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
An asteroid strike would create a huge explosion. NASA feared this might even be mistaken for a nuclear bomb. We wanted folks to know this was a natural event by Mother Nature rather than some sort of man-made event like a missile or something dreadf
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
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
Look at the size of this! This is magnificent! That is beautiful. This cave may be stunning, but it provides the evidence for one of the greatest catastrophes in the Earths history. And that water, its so clear! Lower the gear, please! Theres actuall
探索与发现2014年
Luckily, the very biggest asteroids are few and far between. But there are still plenty of rocks out there that represent a significant danger to us. So, at the summit of an extinct Hawaiian volcano, Professor Nick Kaiser and his colleagues are searc
探索与发现2014年
Tim has developed a map to visualize their location. And on that map, the most important are the Near-Earth asteroids, the ones closest to the planet. On the screen here is a map of the solar system. And Ive got the Sun in the centre and the third pl
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
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
Weknew from the radar measurements where Golevka was within a few tens of metres.And yet it was actually 12 or 15 kilometres away from where it was predicted tobe without Yarkovsky effect. So these very precise radar observations allowedus to see the
探索与发现2014年
Heset out to investigate a hundred-year-old theory that said asteroids werepowered by the Sun itself. It was called the Yarkovsky effect. The Yarkovskyeffect is a very small acceleration and acts on asteroids and what it is is ifyou take a model, the
探索与发现2014年
Well,the early reports are that it is an ordinary chondrite and that means it willbe similar to this one. So this is really exciting for us as scientists becausewe want to know how the planets formed, what was around before the planets, whatthe envir
探索与发现2014年
Itsremarkable how we are able to build up this picture of whats going on millionsof miles away in the solar system. Its one of the joys of science really, justalmost like a detective picking up on those tiny clues to tell a bigger story. Sothat the b
探索与发现2014年
For the residents of the Russian city of Chelyabinsk, the morning of Friday, February 15, 2013 began like any other. As they set off to work in what has become a craze throughout Russia, many recorded their journeys, but these cameras usually used fo
探索与发现2014年
Amazing images. But what can you get out of these asan expert? What it shows us, first of all, is a great record ofthe entry of the object into the Earths atmosphere. So you see it right fromthe moment it really penetrated. And there it is. That is t
探索与发现2014年
By collecting and comparing meteorites, scientistshave been able to piece together a picture of how they form and these studieshave revealed some of the most remarkable rocks in the solar system. Few places in the world have got as many meteoritesas
探索与发现2014年
What would you do in your last 60 minutes?An asteroid is on a collision course with the earth and you have one hour left to live. What would you do in your last 60 minutes? Not surprisingly, the majority of Britons questioned in a survey -- 54 percen
阅读空间
MOSCOW, Feb. 17 (Xinhua) -- Most buildings damaged by Friday's meteorite fall in Russia's central Urals Region have been restored, and educational institutions will operate as usual on Monday. Xinhua reporters saw in the hardest-struck Chelyabinsk Re
英语新闻
The story begins in the early 1950s when a bright young geologist named Eugene Shoemaker paid a visit to Meteor Crater in Arizona. 故事始于20世纪50年代之初。当时，有一位名叫尤金苏梅克的年轻有为的地质学家对亚利桑那
万物简史