for the martians


NASA catches plasma erupting

around the sun.

That was taken by the Solar Dynamics Observatory at about 17:50 UT. The prominence (plasma flare) must be at least half a million kilometers across!

by Bad Astronomy:

A prominence is a loop of gas that erupts from the surface of the Sun. This gas follows the Sun’s magnetic field lines; complicated interplay between the energy stored in the field lines versus their tension causes them to leap up from the Sun, anchored in two spots that represent where the north and south poles of the lines punch through the Sun’s surface.

First, there is very little danger to Earth from this event. Prominences like this tend to be local to the Sun, and collapse after a few hours.

There is no hint of this event in this SDO visible light image taken at nearly the same time. The false-color image of the prominence above is actually taken in the ultraviolet, where low-density helium glows. In visible light, the light from the extremely thin material in the prominence is totally overwhelmed by the intense emission from the Sun’s surface, and is invisible. It’s only when we filter out most of the Sun’s light (and let through light specifically given off by the plasma in the prominence) that we can see it at all.

In visible light, the light from the extremely thin material in the prominence is totally overwhelmed by the intense emission from the Sun’s surface, and is invisible.

Note that the dark sunspots in the visible light image are seen as being very bright in the ultraviolet helium image. The Sun’s magnetic field is incredibly complex, with gigantic loops of magnetic field lines piercing through the Sun’s surface and re-entering some distance away. Sunspots are where the magnetic field strength is high. This prevents the gas from rising and falling in the Sun, so packets of gas boiling up from below reach the surface and cool off a bit, darkening. But in the ultraviolet, the magnetic energy is more easily seen, making the spots look bright.

Bad Astronomy

WOWZERS, the sun is so huge and massive. These mini eruptions on the sun are the first in history that we’ve been able to understand why these eruptions occur. If the eruption was larger, it could have affected satellites  on Earth.

Bonus: