I would like contribute to a fact of general knowledge that most people dont know… (even I didnt, until few months back)
the attached photo illustrates sun from outer space. Now if we notice, the sun is shinning in white light and yes, the real color of sun is actually bright white, with a very little hint of yellow(as oppose to our daily general observation of pale yellow, a color formed by atmospheric diffraction of light by blue ozone layer)
so sun in real, is white and not yellow
Filament Across the Sun
Image Credit & Copyright: Bret Dahl
Is that a cloud hovering over the Sun?
Yes, but it is quite different than a cloud hovering over the Earth. The long light feature on the left of the above color-inverted image is actually a solar filament and is composed of mostly charged hydrogen gas held aloft by the Sun’s looping magnetic field.
By contrast, clouds over the Earth are usually much cooler, composed mostly of tiny water droplets, and are held aloft by upward air motions because they are weigh so little. The above filament was captured on the Sun about two weeks ago near the active solar region AR 1535 visible on the right with dark sunspots.
Filaments typically last for a few days to a week, but a long filament like this might hover over the Sun’s surface for a month or more. Some filaments trigger large Hyder flares if they suddenly collapse back onto the Sun.
1 million Earths
Have you ever tried to visualize how many Earth’s would fit in the Sun? The Sun’s diameter is roughly 100 times larger than the Earth’s so, in volume, that means around 100x100x100 (1 million) Earth’s fit within the Sun. 1 million is a large number and can be tricky to imagine. The Universe Awareness Project in Germany have created this ball of Earth’s to show exactly that. Each small blue ball represents the Earth. The plastic sphere represents the Sun.
Image credit: UNAWE DE/Stuart
Sounding Rocket Mission to Observe Magnetic Fields On the Sun |
On July 5, NASA launched a mission called the Solar Ultraviolet Magnetograph Investigation or SUMI, to study the intricate, constantly changing magnetic fields on the sun in a hard-to-observe area of the sun’s low atmosphere called the chromosphere.
Magnetic fields, and the intense magnetic energy they help marshal, lie at the heart of how the sun can create huge explosions of light such as solar flares and eruptions of particles such as coronal mass ejections (CMEs). While there are already instruments — both on the ground and flying in space — that can measure these fields, each is constrained to observe the fields on a particular layer of the sun’s surface or atmosphere. Moreover, none of them can see the layer SUMI will observe.
“What’s novel with this instrument is that it observes ultraviolet light, when all the others look at infrared or visible light,” says Jonathan Cirtain, a solar scientist at NASA’s Marshall Space Flight Center in Huntsville, Ala. and the principal investigator for SUMI. “Those wavelengths of light correspond to the lowest levels in the sun’s atmosphere, but SUMI will look at locations higher in the chromosphere.”
The chromosphere is a narrow layer above the photosphere that raises in temperature with height. Normally, it can’t be seen by the naked eye because the light from the photosphere of the Sun overpowers it. The coloring of the chromosphere (deep red) is caused by the immense hydrogen supply it contains. continue reading
The most severe space weather in more than six years was expected to hit Earth on Tuesday