Spooky sights in the night sky

Halloween as we know it today has its roots in Samhain, when ancient Celts and Druids in the British Isles marked the end of the harvest and the beginning of longer, darker nights.

The last day of October was chosen for its position midway between the September equinox and the December solstice, a cross-quarter day

Other cross-quarter days include Groundhog Day (February 2), May Day (May 1), and Lammas (August 1), or Loaf Mass Day where some Christian sects celebrate the first fruits of the harvest.

Above tonight's gloomy weather there you'll find some spooky sights.

The Witch Head Nebula in the constellation Orion glows an eerie blue not just because of the blue color of its star, Rigel, but also because the dust grains reflect blue light more efficiently than red.  This is the same physics at work in space that creates the Caroline blue skies back here on Earth.

The Ghost Head Nebula, known to astronomers as NGC 2080, is part of a chain of star-forming regions in the Large Magellanic Cloud.  It has been a popular target for the Hubble Space Telescope through the years. Red and blue in the image are regions of hydrogen gas heated by nearby stars. The comes from oxygen glowing from energy provided by stellar wind, a high-speed stream of particles, supplied by a nearby star.

It may look like the Helix Nebula (NGC 7293) is watching you but the truth is actually spookier. This dying star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core, 650 light-years away, in the constellation of Aquarius.

Our own Sun will suffer this same fate, turning into a planetary nebula, in about five billion years.

Astronomers have to come up with ways to visualize energy outside of the visible spectrum. A skull appears in this image captured by the Chandra Observatory of X-rays emitted by the Perseus cluster of galaxies.