Home > Ephemeris Program, NASA, Sun > 02/17/11 – Ephemeris – The whole sun is visible now

02/17/11 – Ephemeris – The whole sun is visible now

February 17, 2011

Thursday, February 17th.  The sun will rise at 7:39.  It’ll be up for 10 hours and 33 minutes, setting at 6:13.   The moon, 1 day before full, will set at 7:24 tomorrow morning.

Four and a half years ago NASA launched a two spacecraft on a single rocket.  One was sent ahead of the earth, and the other to trail behind the earth in its orbit.  They are called Stereo, and give us a stereo view of the sun.  Earlier this month they reached points 90 degrees ahead and behind the earth.  They now cover the complete sun, front and back.  For the next 9 years we should get coverage of the far side of the sun, so we’ll see what’s brewing in the way of sunspots and other solar phenomena before they rotate around to the side that faces the earth.  The sun rotates slowly, and as a fluid body.  At the equator the sun rotates in 25 days,  at the poles it drops to 36 days.  This differential rotation causes the sun’s magnetic field to tangle and break.

* Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Categories: Ephemeris Program, NASA, Sun
  1. kaye's avatar
    kaye
    February 17, 2011 at 8:05 pm

    hello…my mother and brother seen a black line across the moon this evening feb 17, 2011..she lives in ohio…it started at the top of the moon and within five minutes the black line was around the bottom and then dissappeared ….what is the black line?

    • bobmoler's avatar
      bobmoler
      February 17, 2011 at 8:20 pm

      Hi Kaye,

      I don’t know what the line is. From the speed, it appears that it’s a lot closer than the moon. You didn’t say whether the line was sharp or fuzzy. If fuzzy it could be an aircraft contrail. That’s all I have. Anyone else have an idea?

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