Solar eclipse corona
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Composite image from Proba-2’s SWAP imager (with 174Å filter) showing
the Sun’s disc, with a reconstructed white-light image of the extended
corona taken at exactly the same time from the ground, during the total
solar eclipse observed in July 2010 in Atoll Hao, French Polynesia.
Credits: ESA/Proba-2 consortium/SWAP team/Institut d’Astrophysique de Paris (CNRS & UPMC), S. Koutchmy/J. Mouette
Tomorrow’s total solar eclipse will only be visible in its entirety to
ground-based observers watching from northern Australia, but ESA’s
Sun-watching Proba-2 satellite will have a ringside seat from its orbit
around Earth.
During a total solar eclipse the Moon moves in front of the Sun as seen from Earth, their separation and alignment such that the Moon appears large enough to temporarily block out the Sun’s light.
During a total solar eclipse the Moon moves in front of the Sun as seen from Earth, their separation and alignment such that the Moon appears large enough to temporarily block out the Sun’s light.
An eerie light is cast over ground observers as the imposing black disc of the Moon briefly replaces the Sun’s bright face.
Totality – when the Sun is completely obscured – occurs tomorrow at
22:11:48 GMT over the South Pacific for four minutes and two seconds.
Observers along the east coast of Queensland, Australia, will be the
lucky few to see the total eclipse, enjoying totality for about two
minutes as the Sun rises 14 degrees above the horizon.
During totality the Sun appears to have a white halo – a rare glimpse of
the Sun’s million-degree plasma atmosphere, or corona, which is too
washed out by the Sun’s brightness to be observed normally.
Flying in a 720 km orbit, Proba-2 is the second in ESA's Project for
Onboard Autonomy series, capable of flying itself with minimal support
from the ground. Its purpose is flight-test new technologies and it
carries a total of 17 technology payloads. It also carries four
scientific instruments focused on the Sun and space weather.
In the image presented above, a Proba-2 image of the solar disc taken
during the total eclipse of July 2010 is combined with ground-based
images taken at the same time to reveal the exquisite details of the
solar corona.
A snapshot of the ever-changing environment of the Sun’s magnetic field
is momentarily exposed with plasma streaming out into space, alongside
looping prominences seen much closer to the edge of the solar disc.
During tomorrow’s event Proba-2 will pass through the Moon’s shadow
several times, catching three partial solar eclipses as it orbits around
Earth. At the time of the total eclipse seen from Australia, however,
Proba-2 will see the full solar disc, providing an ideal opportunity to
compare the solar corona from the ground with observations of the Sun
from space.
The satellite’s SWAP instrument will monitor the Sun in extreme
ultraviolet light, while LYRA will measure solar output, which will
become less intense as more of the Sun is obscured.
Please take care if you are lucky enough to be observing this event:
observing the Sun with the naked eye is extremely dangerous and will
cause permanent blindness. Please use certified equipment such as solar
eclipse glasses, or a solar telescope under professional guidance.
ESA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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