Total Solar Eclipse

The Australian Total Solar Eclipse from November 13th/14th (depending on time zones) 2012 can be watched at

What is a Solar Eclipse?

A solar eclipse in when the Moon passes in front of the Sun casting a shadow on the Earth (this is also known as an occultation). As the Sun’s distance from Earth is around 400 times the Moon’s distance and the Sun’s diameter is around 400 times the Moon’s diameter, the Sun and the Moon as seen from Earth appear to be approximately the same size. There are several sorts of eclipses; partial, annular and total.

Partial Solar Eclipse: Occurs when the Moon does not line up with the Sun exactly only partially obscuring it.

Annular Solar Eclipse:  When the Moon is further from the Earth and/or the Earth is closer to the Sun the Moon will appear smaller in comparison to the Sun so during an eclipse will not entirely cover it appearing as a bright ring surrounding the Moon.

Total Solar Eclipse: Occurs when the Moon completely obscures the Sun allowing the fainter solar corona to be visible.

Facts about Solar Eclipses

  • There are between 2 and 5 solar eclipses each year
  • When the Moon completely obscures Sun so only the solar corona can be seen it is called a Totality
  • A total solar eclipse only happens once every 1 and a half years
  • The Moon moves across  the Sun at 2,250 km per hour
  • Only partial solar eclipses can be observed from the North and South Poles
  • The longest a total solar eclipse can last is 7 and a half minutes
  • The width of the path of totality is at most 269 km wide
  • Almost identical eclipses occur after 18 years and 11 days, this is known as the Saros Cycle