Tuesday, July 7, 2009

lunar eclipse july 2009

lunar eclipse july 2009

For those who follow Astronomy and Astrology, the Total Solar Eclipse of July 22, 2009 is of extreme importance as it is the longest one the Earth will experience in the 21st century until June 13, 2132. NASA published the eclipse's path as projected by Fred Espenak and Jay Anderson. These spots are the best places on Earth to view this most anticipated eclipse.

Explorers who wish to experience this event first hand would need to travel to parts of Asia to see the total solar eclipse. A few of these places are still under alert for travelers. Check out the article on legal and political matters related to holistic travel abroad for information on travel alerts and warnings.

On Wednesday, 2009 July 22, an exceptionally long total eclipse of the Sun is visible from within a narrow corridor that traverses the Eastern Hemisphere. The path of the Moon’s umbral shadow begins in India and crosses through Nepal, Bangladesh, Bhutan, Burma, and China. After leaving mainland Asia, the path crosses Japan’s Ryukyu Islands and curves southeast through the Pacific Ocean where the maximum duration of totality reaches 6 min 39 s (Espenak and Anderson 2006). A partial eclipse is seen within the much broader path of the Moon’s penumbral shadow, which includes most of eastern Asia, Indonesia, and the Pacific Ocean.

Umbral Path and Visibility

The central line of the Moon’s shadow begins at 00:53 UT (Universal Time) in India’s Gulf of Khambhat (Bay of Cambay). Because the Moon passes through perigee just 4 ½ hours earlier (July 21 at 20:16 UT), its close proximity to Earth produces an unusually wide path of totality.

The eclipse track is 205 km wide at its start as the umbra quickly travels east-northeast. The Sun is only 3° above the northeastern horizon when the coastal city of Surat, India (pop. ~4 million) experiences a 3 min 14 s total eclipse. Racing inland, the shadow reaches Indore where its 1.8 million inhabitants are plunged into totality for 3 min 5 s.

At mid-eclipse (00:53:30 UT), the Sun hangs a mere 6° above the horizon. After covering 700 km along the central line in the first 39 seconds of its 3+ hour-long trajectory across our planet, the umbra’s ground speed is rapidly decelerating. Nevertheless, with a velocity of 8.9 km/s, it still exceeds the speed of sound (1230 km/h) by a factor of 26 times. Bhopal (pop. 1.5 million) lies 40 km north of the central line. Even at this distance, it succumbs to 3 min 9 s of the total phase, just 19 s less than the maximum duration at the path’s center. By 00:55 UT, the umbra is in central India where it stretches diagonally across 2/3 of the country.

Due to the Sun’s low altitude, the shadow is a highly elongated ellipse with a major axis of ~1000 km, nearly 5 times its minor axis. Approximately 400 km north of the path, the Taj Mahal in Agra experiences a deep partial eclipse of magnitude 0.906 at 00:56 UT. Just three minutes into its course, the path width is 218 km while the shadow’s velocity drops to 3.8 km/s. On the central line, the Sun stands 14° above the horizon during the 3 min 45 s total phase. Varanasi and Pata both lie within the shadow’s path as the central line crosses the sacred Ganges River.

About 500 km to the southeast, the populace of Kolkata (Calcutta, pop. ~4.5 million) can view a partial eclipse of magnitude 0.911. Eastern India narrows to a 25-km-wide corridor as it squeezes between Nepal and Bangladesh. The shadow reaches this region at 00:58 UT. Outside the path, Kathmandu experiences a partial eclipse of magnitude 0.962, while Dacca witnesses a 0.930 magnitude event. The eclipse’s central line reaches Bhutan, at 00:59 UT. Now six minutes and 2000+ km into its trek, the path width has grown to 224 km, the ground velocity is 2.6 km/s and the central duration exceeds 4 min.

After leaving Bhutan, the track continues through India in the northeastern states of Arunachal Pradesh and Assam. The center of the umbra reaches the India-China border at 01:05 UT. The Sun is now 28° high, the shadow’s ground velocity is 1.8 km/s and the duration of totality is 4 min 26 s. The southern half of the umbra briefly sweeps across northern Burma (Myanmar) before the entire shadow enters China’s Yunnan province and the Tibet Autonomous Region.

The lunar shadow runs through the middle of Sichuan province where the capital city of Chengdu (pop. ~2.3 million) is totally eclipsed for 3 min 16 s at 01:13 UT. On the central line 88 km to the south, the duration is 4 min 52 s. The urban center of the Chongqing municipality is 69 km south of the central line (Figure 12), but its ~4.1 million inhabitants still share a totality lasting 4 min 06 s (01:15 UT). Because all of China is in one time zone (UT + 8 h), UT times and can be converted to local Chinese time by adding 8 hours. Hubei province’s capital Wuhan (pop. ~ 9.7 million) is the fourth largest city in China. It lies just 20 km south of the central line and enjoys a duration of 5 min 25 s at 01:27 UT.

The Sun’s altitude is 48°, the path width is 244 km and the umbra’s velocity is 1.0 km/s. The Yangtze River meanders through the eclipse track as the shadow proceeds east. Hangzhou (pop. ~3.9 million), the capital of Zhejiang province, is 52 km south of the central line and witnesses a total eclipse of 5 min 19 s (01:37 UT). In spite of Hangzhou’s location, only 32 s are to be gained by traveling north to the central line where the duration is 5 min 51 s. Shanghai is China’s largest city (pop. ~18.7 million). Located 66 km north of the central line, Shanghai still manages to receive 5 min of totality (01:39 UT). While the central line offers a total phase lasting 5 min 55 s, it is already over Hangzhou Bay and heading out to sea. The 128 islands of the Dinghai district southeast of Shanghai, make up the last Chinese land within the eclipse track (01:41 UT).

After crossing the East China Sea, the umbra encounters Japan’s Ryukyu Islands (a.k.a. Nansei Islands) at 01:57 UT. The chain contains dozens of islands stretching across the entire eclipse path. Yakushima, the largest island in the path is near the northern limit and experiences 3 min 57 s of totality. Akuseki-shima is closest to the central line; it gets a 6 min 20 s total eclipse. To the north, Tokyo, Japan’s capital city witnesses a partial eclipse of magnitude 0.747 (02:13 UT).

The shadow encounters the remote Japanese islands of Iwo Jima and Kitaio Jima at approximately 02:27 UT. The durations of totality from the two islands are 5 min 13 s and 6 min 34 s, respectively. The instant of greatest eclipse occurs at 02:35:19 UT (latitude 24° 13?N, longitude 144° 07?E) when the axis of the Moon’s shadow passes closest to the center of Earth (gamma1 = +0.06977). The maximum duration of totality here is 6 min 39 s, the Sun’s altitude is 86°, the path width is 258 km, and the umbra’s velocity is 0.65 km/s.

Having already traversed 7550 km, the central line has an additional 7600 km to go until its terminus. Unfortunately, the remainder of the path makes no major landfall; it arcs southeast through the Pacific Ocean hitting only a handful of small atolls. Nearly an hour passes before the Moon’s shadow reaches Enewetak Atoll in the Marshall Islands. Infamous for its use as a nuclear test site in the 1950s, Enewetak experiences a total eclipse with a duration of 5 min 38 s at 03:31 UT. The Sun’s altitude is 57°, the path width is 254 km, and the umbra’s velocity is 0.85 km/s. Several other Marshall Islands atolls are in the eclipse track including Namorik, Kili, and Jaluit.

Continuing through Kiribati (Gilbert Islands), Butaritari atoll lies near the central line (Figure 18) where the maximum duration of 4 min 48 s occurs at 03:56 UT. The eclipse track’s final landfall takes place on Nikumaroro Island (Gardner Island) in Kiribati’s Phoenix Island group.

From Nikumaroro, the total phase lasts 3 min 39 s, while the central line 40 km to the south offers a duration of 3 min 58 s (04:11 UT). The Sun’s altitude is 20°, the path width is 228 km and the ground speed is 2.6 km/s. The lunar shadow once again becomes a long, drawn-out ellipse. In its final few minutes, the umbra’s velocity accelerates while the Sun’s altitude and the central duration decrease. As the Moon’s shadow lifts off Earth and returns to space, the central line ends at 04:18 UT.

Over the course of 3 h 25 min, the umbra travels along a track approximately 15,150 km long that covers 0.71% of Earth’s surface area.

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