Here's a trick of the eye that's also a treat for Halloween: the Witch Head nebula, as seen in infrared wavelengths by NASA's Wide-Field Infrared Survey Explorer, or WISE. It's just one of the images featured in October's Month in Space slideshow.
The nebula gets its witchy name because of its appearance: There's a long nose that points out toward the right, with a gaping toothless mouth below. The Witch Head, which also carries the designation IC 2118, is actually a cloud of gas and dust associated with the bright star Rigel in the constellation Orion, about 850 light-years from Earth. This wide-angle picture provides a different perspective, making it look as if the witch is staring at the star.
The nebula's glow primarily consists of starlight from Rigel, reflected and scattered by the cloud. In real life, the cloud has a bluish cast to it, but WISE's false-color version adds an appropriately ghoulish green tint. You'll find lots more visual treats in our slideshow selection, including a three-headed astronaut, an ultraviolet view of a violent solar storm, and a 3-D view of the moon that's worth getting red-blue glasses to see. And here's the best part: These Halloween treats are calorie-free.
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with NBCNews.com's stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.