Solar eclipse

As seen from the Earth, a solar eclipse is a type of eclipse that occurs when the Moon passes between the Sun and Earth, and the Moon fully or partially blocks ("occults") the Sun. This can happen only at new moon, when the Sun and the Moon are in conjunction as seen from Earth in an alignment referred to as syzygy. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses, only part of the Sun is obscured.

If the Moon were in a perfectly circular orbit, a little closer to the Earth, and in the same orbital plane, there would be total solar eclipses every month. However, the Moon's orbit is inclined (tilted) at more than 5 degrees to the Earth's orbit around the Sun (see ecliptic), so its shadow at new moon usually misses Earth. Earth's orbit is called the ecliptic plane as the Moon's orbit must cross this plane in order for an eclipse (both solar as well as lunar) to occur. In addition, the Moon's actual orbit is elliptical, often taking it far enough away from Earth that its apparent size is not large enough to block the Sun totally. The orbital planes cross each other at a line of nodes resulting in at least two, and up to five, solar eclipses occurring each year; no more than two of which can be total eclipses. However, total solar eclipses are rare at any particular location because totality exists only along a narrow path on the Earth's surface traced by the Moon's shadow or umbra.

Mursili's eclipse

The solar eclipse mentioned in a text dating to the reign of Mursili II could be of great importance for the absolute chronology of the Hittite Empire within the chronology of the Ancient Near East. The text records an "omen of the sun," linked to the tenth year of Mursili's reign, which appeared just as he was about to launch a campaign against the Kingdom of Azzi-Hayasa in north-eastern Anatolia. According to the current debate, there are two possible candidates for the eclipse: 13 April 1308 BC or 24 June 1312 BC. The 1312 BC date is accepted by most Hittitologists, e.g. Trevor Bryce (1998), while Paul Åström (1993) has suggested the 1308 BC date.

The 1312 eclipse occurred over northern Anatolia in the early afternoon, and its effects would have been quite spectacular for Mursili and his men on campaign:

In contrast, the 1308 eclipse was annular, and began very early in the morning over Arabia (and only penumbral over Anatolia and Syria), reaching its height over Central Asia:

Solar eclipse of July 22, 2009

A total solar eclipse occurred on July 22, 2009. It was the longest total solar eclipse during the 21st century, not to be surpassed until 13 June 2132. It lasted a maximum of 6 minutes and 39 seconds off the coast of Southeast Asia, causing tourist interest in eastern China, Japan, India, Nepal and Bangladesh.

Visibility

A partial eclipse was seen within the broad path of the Moon's penumbra, including most of Southeast Asia (all of India and China) and north-eastern Oceania.

The total eclipse was visible from a narrow corridor through northern India, eastern Nepal, northern Bangladesh, Bhutan, the northern tip of Myanmar, central China and the Pacific Ocean, including northern part of the Ryukyu Islands, Marshall Islands, and Kiribati.

Totality was visible in many large cities, including Surat, Vadodara, Bhopal, Varanasi, Patna, Gaya, Dinajpur, Siliguri, Guwahati, Tawang in India and Chengdu, Nanchong, Chongqing, Yichang, Jingzhou, Wuhan, Huanggang, Hefei, Hangzhou, Wuxi, Huzhou, Suzhou, Jiaxing, Ningbo, Shanghai, Chapai Nawabganj as well as over the Three Gorges Dam in China. However, in Shanghai, the largest city in the eclipse's path, the view was obscured by heavy clouds. According to NASA, the Japanese island Kitaio Jima was predicted to have the best viewing conditions featuring both longer viewing time (being the closest point of land to the point of greatest eclipse) and lower cloud cover statistics than all of continental Asia. The Indian city of Varanasi had similar conditions to those in Kitaio Jima; although the eclipse was the longest there than anywhere else.