• NASA's Hubble shared an image of a star cluster that contains some of the oldest stars in the galaxy
  • The globular star cluster, identified as Messier 107, is one of more than 150 at the outer parts of the Milky Way Galaxy
  • The origin of globular clusters, and the role they play in the universe, remain a mystery to scientists

NASA's Hubble Space Telescope took a fascinating snapshot of a cluster of stars located about 20,000 light-years away from the solar system. The star cluster, identified as Messier 107, resembled a stadium darkened before a show, with nothing but the lights of the audience's flashbulbs illuminating it.

The Hubble image featured Messier 107, one of more than 150 globular star clusters found around the discs of the Milky Way galaxy. These clusters contain hundreds of thousands of extremely old stars -- some of the oldest objects in the Milky Way. The image was posted Wednesday on the space agency's website and has since garnered flattering remarks due to its bright hues of blue, white and yellow.

"Messier 107 can be found in the constellation of Ophiuchus (The Serpent Bearer) and is located about 20,000 light-years from our solar system," noted NASA in the image's caption.

To date, the origin of these spherical collections of stars is considered a mystery, as astronomers and scientists are still learning how exactly they came about, and what role they play in the giant puzzle that is the universe.

Globular star cluster Messier 107 was first discovered in 1782 by French astronomer Pierre Méchain, with British astronomer William Herschel documenting it independently a year later. It was in 1947 when Canadian astronomer named Helen Sawyer Hogg added the star cluster to Charles Messier's famous astronomical catalog.

Globular clusters are tightly packed, symmetrical collections of stars that usually orbit a spiral galaxy's star halos. These clusters contain the oldest stars in the galaxy, which are considered to be among the oldest objects in the universe. According to EarthSky, scientists can find out a globular cluster's age by looking at its almost complete lack of what they call metals -- elements heavier than the hydrogen and helium present in the early universe before the first stars and galaxies were born.

Globular clusters can reach about 300-light years in diameter and contain 10 million stars. Unlike open star clusters, which are more irregular in shape, globular clusters are symmetrical and are densest toward their centers.