文章列表

• 1.英语听力：探索发现 2014-06-20 BBC 地平线：陨石的真相-17
• 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...
• 2.英语听力：探索发现 2014-06-18 BBC 地平线：陨石的真相-16
• 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 aste...
• 3.英语听力：探索发现 2014-06-15 BBC 地平线：陨石的真相-15
• On June 30th, 1908, a huge explosion tore through the forest of Tunguska, Siberia. It was 20 years before the Russians mounted an expedition to the si...
• 4.英语听力：探索发现 2014-06-13 BBC 地平线：陨石的真相-14
• So was this a near miss for us? If the asteroid had been in a different part of its orbit, so it didnt hit this year but it hit next year, it would ha...
• 5.英语听力：探索发现 2014-06-11 BBC 地平线：陨石的真相-13
• There it is! Yep. Its about 90 kilometres up, at that stage, travelling at 17.5 kilometres per second. Using the different camera positions, scientist...
• 6.英语听力：探索发现 2014-06-08 BBC 地平线：陨石的真相-12
• 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 ...
• 7.英语听力：探索发现 2014-06-06 BBC 地平线：陨石的真相-11
• 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 pr...
• 8.英语听力：探索发现 2014-06-04 BBC 地平线：陨石的真相-10
• Heset out to investigate a hundred-year-old theory that said asteroids werepowered by the Sun itself. It was called the Yarkovsky effect. The Yarkovsk...
• 9.英语听力：探索发现 2014-05-30 BBC 地平线：陨石的真相-9
• 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 rea...
• 10.英语听力：探索发现 2014-05-28 BBC 地平线：陨石的真相-8
• 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 scienti...