APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Active Prominences on a Quiet Sun
Explanation: Why is the Sun so quiet? As the Sun enters into a period of time known as a Solar Minimum , it is, as expected, showing fewer sunspots and active regions than usual. The quietness is somewhat unsettling , though, as so far this year, most days show no sunspots at all. In contrast, from 2011 - 2015, during Solar Maximum , the Sun displayed spots just about every day. Maxima and minima occur on an 11-year cycle , with the last Solar Minimum being the most quiet in a century. Will this current Solar Minimum go even deeper ? Even though the Sun's activity affects the Earth and its surroundings, no one knows for sure what the Sun will do next , and the physics behind the processes remain an active topic of research . The featured image was taken three weeks ago and shows that our Sun is busy even on a quiet day. Prominences of hot plasma , some larger than the Earth , dance continually and are most easily visible over the edge.
| Date | August 20, 2018 |
|---|---|
| Credit | Image Credit & Copyright: Alan Friedman ( Averted Imagination ) |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



