Thursday, September 17, 2015

Super Harvest Blood Moon Lunar Eclipse Tetrad, 27-28 September 2015



from Sky & Telescope
Isn’t it a little early for Halloween? The Blood Moon really has nothing to do with Halloween even though it sounds like it might. A “blood moon” occurs when there is a total lunar eclipse during a full moon. It’s that simple.

...and it's the Harvest Moon because it's the full moon nearest to the autumnal equinox.


Why is it called a “blood” moon? First, lunar eclipses: When the Earth comes between the sun and the moon, the shadow of the Earth crosses the moon and creates an eclipse.These can be partial or total. Total eclipses happen when the entire moon passes through the umbra or center of the Earth's shadow, darkening the whole face.

Sunlight will still light up the moon by traveling around the Earth and creates a reddish tinge due to dust and organic matter in the atmosphere. This happens with every lunar eclipse but the effect is more vivid during a full moon because there is just more bright moon surface to see it with.

Why is it "super" and what is a "tetrad'? Supermoons happen when the moon is at "perigee" - i.e. when the moon is closest to the Earth in its orbit which makes them appear a bit larger in the sky. The tetrad part refers to the fact that four total lunar eclipses have happened in a row. The last three were 15 April 2014, 08 October 2014, and 04 April 2015. The upcoming one on the 27th will complete the tetrad.

Weather-permitting, you will be able to see this blood moon the night of September 27-28th.
EventUTC TimeTime in Indianapolis*Visible in Indianapolis
Penumbral Eclipse beginsSep 28 at 12:11 AMSep 27 at 8:11 PMYes
Partial Eclipse beginsSep 28 at 1:07 AMSep 27 at 9:07 PMYes
Full Eclipse beginsSep 28 at 2:11 AMSep 27 at 10:11 PMYes
Maximum EclipseSep 28 at 2:47 AMSep 27 at 10:47 PMYes
Full Eclipse endsSep 28 at 3:23 AMSep 27 at 11:23 PMYes
Partial Eclipse endsSep 28 at 4:27 AMSep 28 at 12:27 AMYes
Penumbral Eclipse endsSep 28 at 5:22 AMSep 28 at 1:22 AMYes
(table from timeanddate.com)


Know more...
From the Libraries & Ball State:

  • Call no. ranges for astronomy:
    • Astronomy = QB
      • 63 stargazers guide
      •  414-419 theory of tides
      • 500.5-785 solar system
      • 630-638 earth as planet
  • Ball State University's Charles W. Brown Planetarium program: Moons: Worlds of Mystery 
From non-Ball State sources: