Total Lunar Eclipse of September 27, 2015
A Super Moon Eclipse!

The fourth lunar eclipse in the last 18 months will occur on Sunday night, September 27, 2015. This eclipse will be visible across much of North America (as well as other locations). As long as the skies are clear in New Mexico, the eclipse will be visible just after moonrise.

Additionally, this eclipse will occur during a "Super Moon" when the mood appears 7% larger than average!

A lunar eclipse occurs only during a full moon, when the moon passes through the shadow of the earth (see diagram below).  During a total lunar eclipse, the moon often has a vibrant red-orange hue, as shown in the photograph to the right, taken by Becky Ramotowski in Tijeras in 2009. 

This striking color is due to the Earth's atmosphere!  Without an atmosphere, the moon would be black during a total lunar eclipse.  However, small particles in the atmosphere both refract and scatter sunlight. As with a sunset, the shorter wavelengths of the sun's visible light (blue and violet) are scattered the most, with the longer wavelenths (red and orange) remaining.  The amount of dust in the atmosphere and the presence of clouds affect the color of the moon during an eclipse.


Lunar eclipses are considered total when the moon passes completely into Earth's umbral, or darkest, shadow. The eclipses are viewable from the night side of the earth.


Earth's shadow is cone-shaped and is defined by two areas.  The umbra is the darkest portion of the earth's shadow (dark gray in the figure to the right) and is the area where the sun's light is completely blocked.  The penumbra is the transitional area between the regions of total shadow and total illumination (light gray on the figure).  As the moon moves from the penumbra to the umbra during a total lunar eclipse, the illuminated moon will take on the orange or red glow.

graphic of Earths shadow on moon

The graphic below is a schematic of the upcoming solar eclipse  (times are MDT):

graphic of lunar eclipse

(More specifice details are available here.)


For more information on the lunar eclipse, vist the NASA lunar eclipse site.

For some photos from previous lunar eclipse events, see the NASA eclipse photography page and the NASA Astronomy picture of the day. is the U.S. government's official web portal to all federal, state and local government web resources and services.