Hubble can Still Impress and Inspire. Here's Globular Star Cluster NGC 6638

Wow, what a beauty! While we’ve all turned our attentions to the new James Webb Space Telescope, this image proves Hubble has still has got it where it counts.  

This new image from the Hubble Space Telescope shows the heart of the globular cluster NGC 6638 in the constellation Sagittarius. This star-studded cluster contains tens of thousands to millions of stars, all tightly bound together by gravity. Globular clusters have a higher concentration of stars towards their centers, and this observation highlights that density.

This image was taken with Hubble’s Wide Field Camera 3 and the Advanced Camera for Surveys.

Like so many things that Hubble has observed since it launched to space in 1989, this venerable telescope has revolutionized the study of globular clusters. With its instruments and clear vision above Earth’s atmosphere, Hubble has been able to study what kind of stars make up globular clusters, how they evolve, and the role of gravity in these dense systems.

What Hubble Has Shown Us About Globular Clusters

Globular clusters are found in nearly all galaxies. They are the largest and most massive type of star clusters, and they tend to be older and denser than open clusters. From Hubble, we’ve learned that the  typical distance between stars in a globular cluster is about one light year. But at the central core of a cluster where the concentration of stars is the highest, the distance there between stars averages about a third of a light year, or thirteen times closer than Proxima Centauri is to our Sun.

The Milky Way has more than 150 known globular star clusters, but with Hubble and now JWST, both telescopes will continue to search for more that may be out there and tell us more about these ancient beauties.

You can find zoomable versions of this image here, as well as larger versions and wallpaper downloads.

Sources: NASA, ESA

Nancy Atkinson

Nancy has been with Universe Today since 2004, and has published over 6,000 articles on space exploration, astronomy, science and technology. She is the author of two books: "Eight Years to the Moon: the History of the Apollo Missions," (2019) which shares the stories of 60 engineers and scientists who worked behind the scenes to make landing on the Moon possible; and "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos" (2016) tells the stories of those who work on NASA's robotic missions to explore the Solar System and beyond. Follow Nancy on Twitter at and and Instagram at and

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