October's edition of the Journal of the British Astronomical Association has an excellent article regarding the 2008 solar eclipse which will be total when viewed from certain parts of Canada, Russia and China. Most of the information is available from the NASA web site but just in case you don't have the time or the inclination, here's a preview.
On Friday, August 1st 2008 a total solar eclipse will be viewable from the Northern Hemisphere. The small corridor of total eclipse is estimated to be around 200 km wide and will be traveling at approximately 0.6 km/s at ground level.
At 09:23 UT the moons umbral shadow will touch the surface of the earth in Nunavut, Northern Canada. As you can see the path then takes it out on a north eastern trajectory across the Naires Straight and on across the northern end of Greenland and reaches land again at the northern coast of Novaya Zemlya at approximately 10:00 UT. The instant of greatest eclipse occurs at 10:21 UT (latitude 65° 39'N, longitude 72° 18'E) when the axis of the Moon’s shadow passes closest to the centre of Earth (gamma = +0.8307, where gamma is the minimum distance of the Moon’s shadow axis from Earth’s centre in units of equatorial Earth radii). Totality reaches its maximum duration of 2min 27s, the Sun’s altitude is 34°, the path width is 237km and the umbra’s velocity is 0.507 km/s.
This more detailed map shows the resulting path across Russia, Kazakhstan and China. The centre of the track follows the China-Mongolia border for several hundred kilometres while the central duration and the Sun's altitude both decrease. From Altay, China, the total eclipse begins at 10:59 UT and lasts 1min 25s with the Sun 25° above the horizon. Across the border, western Mongolia is very sparsely populated and the Altan Mountains bring cloudiness to the area. Ten minutes later, the umbra just misses Hami, China where a deep partial eclipse of magnitude 0.998 occurs at 11:10 UT. This region in northwest China is noteworthy because it offers some of the most promising weather prospects along the entire eclipse path. Its position between the Gobi Desert to the east and the Talikmakan Desert to the west spares it from the monsoon systems that affect much of Southeast Asia during the summer months.
The best place to watch the eclipse is from the Gobi Desert in China. For those of you who are die hard solar eclipse hunters, the adventure travel company Explore, has a holiday that coincides with the eclipse here.
The reason for watching the eclipse from the Gobi Desert is the chance of good weather. The above diagram shows the average cloud coverage over the path of the eclipse. As you can see the cloud cover drops dramatically around the Chinese town of Hami. There will be a partial eclipse across most of northern Europe so if you can't make it to Hami, don't worry. Get your Solar scope out and enjoy.
0 comments:
Post a Comment