NASA Photo Shows Dark 'Hole in the Sky' Nebula That Absorbs Starlight

NASA has released an image of a spooky pitch-black nebula that is blocking starlight.

Nebulae—giant interstellar clouds of gas and dust—may often be thought of as explosions of color.

The so-called Pillars of Creation, found in the Eagle Nebula, are one example. Nebulae can have stunning coloration as they reflect starlight towards Earth.

Others are ionized and produce their own light due to ultraviolet radiation from nearby stars.

But some nebulae are so dense that they are totally opaque when we try to look at them with visible wavelengths. Instead of lighting up a small pocket of the cosmos, they appear as dark blotches. According to NASA, they are sometimes referred to as "holes in the sky."

A photo of one such dark nebula was released by NASA on Monday. It was captured by the Hubble Space Telescope.

Called LDN 1165, the dark space cloud is located in the constellation Cepheus. It neither reflects nor emits light, instead blocking the light from any stars behind or within it.

Yet despite LDN 1165's lack of color, some of the nebula may actually be full of activity. Dark nebulae can sometimes form stellar nurseries, in which stars are born.

Indeed, Hubble was looking around the location of LDN 1165 specifically as part of a study of new baby stars also known as protostars.

These protostars are not quite fully-fledged stars yet. Instead, they are slowly gathering gas and dust by the force of their own gravity before they eventually burst into life when heat and pressure is sufficient to begin nuclear fusion reactions.

NASA thinks that one particular area of LDN 1165—a small patch glowing orange and white, pictured below—is probably a star-forming region in which there may be multiple protostars.

LDN 1165
This NASA photo shows a small portion of LDN 1165 taken by the Hubble Telescope. Specifically the portion of the nebula may hint at protostars inside. NASA / ESA / T. Megeath University of Toledo), K. Stapelfeldt (Jet Propulsion Laboratory

Another example of a dark nebula is the Horsehead Nebula located in the Orion constellation.

The large, dark molecular cloud is so named because it appears to be shaped like a horse's head. It's pictured against a colorful backdrop of ionized hydrogen gas behind it.

Some nebulae are spectacularly big. The largest-known nebula in the universe, the Tarantula Nebula, spans more than 1,800 light-years across at its longest span, according to LiveScience. It's located 170,000 light-years away from Earth. Within its folds of gas, young stars are being born.

To put the Tarantula Nebula's size into perspective, the Orion Nebula, which is another stellar nursery located a mere 1,500 light-years away from Earth, has a diameter of about 24 light-years.