On 13th November 2012
a solar eclipse will occur over North Australia and the Pacific ocean.
A GLORIA project exepdition will be there to broadcast 'live' the event.
A solar eclipse occurs when the Moon passes between the Sun and Earth
and the Moon fully or partially blocks the Sun from our view.
This can happen only at New Moon (Moon between the Sun and Earth)
and if the Sun and the Moon are perfectly aligned as seen from Earth.
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.
The orbit of the Moon around the Earth is tilted relative to the Earth's orbital plane around the Sun,
the ecliptic plane.
Most of the time the Moon is above or below the ecliptic plane.
For a solar eclipse to occur,
the Moon has to be in, or very close to, the plane of the ecliptic and in New Moon phase.
Solar eclipses are seen on Earth only because of the happy coincidence that,
at some times during the year, the angular sizes of the Moon and Sun are identical.
Hundreds of millions of years in the past, the Moon was too close to the Earth to precisely cover the Sun as we can now observe.
Tidal forces cause the orbit
of the Moon around Earth to increase by about 3.8 cm each year.
In just under 1.4 billion years, the last total solar eclipse visible from Earth will occur!
Solar eclipses have played a very important role in the history of science.
For example, the 1919 eclipse expedition of Sir Arthur Eddington
provided one the first experimental verifications
of the prediction of Einstein's general theory of relativity,
a theory we now rely on for global navigation systems!
Because the shadow of the Moon is narrow, solar eclipses are only visible
in a relatively narrow band on Earth's surface.
They are observed at a specific point on the Earth's surface, such as a city,
on average only once every 375 years.
Most people must make long journeys to be in the band
of totality and to witness the entire event.
On average, a total eclipse will last about 3 minutes with
the longest lasting up to 7 and a half minutes.
After more than a year without total solar eclipses
the Moon's shadow will revisit the Earth's surface on 13th November 2012.
The journey of the shadow begins in Australia and will then move to the Pacific Ocean.
The maximum eclipse will occur at 10:11pm UT
in the middle of the Pacific Ocean
with a duration of 4 minutes and 2 seconds.
The GLORIA project will broadcast the event live
from three observation points in northestern Australia around the city of Cairns,
where the eclipse will have an average duration of about 2 minutes.
The expedition and transmission will be coordinated
and directed by Dr. Miquel Serra-Ricart, Astronomer of GLORIA.
A total solar eclipse is a spectacular natural phenomenon!
For the few minutes of totality, when night takes over day,
animals go to sleep, the stars come out and the air temperature drops.
GLORIA will have weather sensors at its recording stations in Australia.
Students will be able to use these data to record the delay
between the Sun's 'obscuration' and the biggest drop in temperature during the eclipse.
It is vital never to look at the Sun without safe glasses designed specifically for solar viewing.
During all observations of a solar eclipse, except for the few minutes of totality,
adequate eye protection must be worn.
For more information on this and other GLORIA activities,
please go to gloria-project.eu
GLORIA is funded by the EU-FP7 under the e-Infrastructures programme.