Longest blank sun since 2010

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The sun has now been blank of sunspots for five days, the longest such stretch since 2010, during the last stages of the last solar minimum.

Nor is this blank stretch over. Though I have no doubt that sunspots will return to the Sun in the next few days, this sudden arrival of blank days suggests again that the solar maximum might be ending far sooner than presently predicted.


  • Willi

    Spots on the far side aren’t counted, right?

  • For purposes of determining sunspot numbers, yes, farside spots are not counted. This is simply to maintain a consistent counting system from before the space age, when there were no space probes capable of seeing the far side.

  • mpthompson

    Do we currently have space probes to monitor the far side of the sun on a regular basis? My memory whether we launched such probes is vague.

  • We have a pair of satellites called Stereo specifically designed to see the entire face of the sun.

    Update: I forgot to add that one of the two Stereo craft was lost in 2014, which makes it difficult to get complete coverage at this time.

  • Willi

    So, if a sun spot can’t be seen then it doesn’t exist…

  • Willi: Of course not. As I said, they only count the spots on the near side because, until the space age, that was all they could see and count. In order to have the sunspot count remain consistent they use only the nearside spots in the count. However, in studying the sun and its solar cycle solar sciences absolutely do not ignore the far side. This is why the Stereo spacecraft were launched and built, to give sciences a 360 degree view of the sun.

  • Willi

    I wasn’t being serious, just trying to play off “If a tree falls in a forest and no one is around to hear it…”

  • Joe

    Willi, read your second comment and knew exactly where you were going with it, humor not lost on all of us!

  • Max

    If the dark spots on the sun were dark matter…
    Then they would exist even though no one has ever seen one :)

    A news report today said “the ozone hole is smaller this year”. They’re giving the banning of CFCs the credit even though it’s always small during a solar decline. Someday they will connect the dots between ozone consumption and stratospheric clouds from solar activity.

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