Suggested Searches

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.

See Explanation. Clicking on the picture will download the highest resolution version available.

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.