29 May 2010 - Aurora Australis photographed by a crew member on the International Space Station. Credit: NASA
ISS023-E-58455 - On
May 29, looking southward from a
vantage point about 350 kilometers above
the southern Indian Ocean,
astronauts onboard the
Space Station watched this
enormous, green ribbon
lights, the shifting,
bands are commonly seen at high northern latitudes as well,
there known as the aurora borealis or northern lights.
or south their cause is the same
as energetic charged particles from
the magnetosphere pile into the atmosphere near the Earth's poles.
To produce the characteristic greenish glow, the energetic
particles excite oxygen atoms at altitudes of 100 kilometers or more.
Aurora on May 29 were
by the interaction of the magnetosphere with a
coronal mass ejection
from the Sun on May 24.
Expedition 23 Crew,
Green flash: The Aurora Australis (Southern Lights) as observed From the International Space Station. The curve of the Earth and the blue light of the atmosphere can also be seen
The ISS was over the Southern Indian Ocean at an altitude of 350 km, with the astronauts looking towards Antarctica and the South Pole.
Dense cloud cover is dimly visible below the aurora. The curvature of the Earth’s horizon can be clearly seen as well as the faint blue line of the upper atmosphere.
Antarctic glacier melting due to hidden ice ridge (rather than climate change)
The stunning sight is formed as charged particles streaming from the Sun – known as the solar wind - interact with Earth’s magnetic field, resulting in collisions with atoms of oxygen and nitrogen in the upper atmosphere.
This striking aurora image was taken during a geomagnetic storm that was probably caused by a coronal mass ejection from the Sun on May 24th.
The atoms emit photons as a means of returning to their original energy state. The photons form the aurora that we see.
Down to Earth: A more typical view of the Southern Lights over the Amundsen-Scott station at the South Pole taken in 2002
The most commonly observed colour of aurora is green, caused by photons (light) emitted by excited oxygen atoms at wavelengths centered at 0.558 micrometers, or millionths of a metre.
Visible light is reflected from healthy (green) plant leaves at approximately the same wavelength.
Red aurora are generated by light emitted at a longer wavelength (0.630 micrometers), and other colours such as blue and purple are also sometimes observed.
While aurora are generally only visible close to the poles, severe magnetic storms impacting the Earth’s magnetic field can shift them towards the equator.
Credit: Daily Mail, UK