NASA launched the Hubble Space Telescope in 1990 - 30 years ago. Although its anniversary is actually in April, now in December NASA has launched a celebration. To commemorate Hubble's birthday, then. the agency has released 50 incredible new photos of 30 different space objects captured by the powerful telescope.

Although still active, the retirement of the three-decade-old telescope is approaching. The launch of the constantly delayed James Webb Space Telescope will surely come soon. Webb, hundreds of times more powerful, and with cutting-edge technology will replace the old (but still powerful and versatile) Hubble, which has served much in explaining much of what we see through space during its three decades oflife.

Caldwell 83. (NASA, ESA, and H. Falcke (Max Planck Institute for Radio Astronomy); Processing: Gladys Kober (NASA/Catholic University of America)).

Hubble's birthday pictures

With Hubble data, then, NASA has newly processed images of 30 galaxies, star clusters and nebulae. Or, more poetically, "30 dazzling galaxies, shimmering star clusters and ethereal nebulae," in the agency's words.

So, we will place some of the images along the text. Access the complete list of images through this link. The new images have a red stamp saying 'NEW'. It's easy to find. Have fun!

An interesting point, is that the agency carefully chose which objects they would process (in fact, as you will see ahead, Caldwell took care). You can see each of them from Earth, using binoculars, telescopes, or even the naked eye. So, do a test. Using a sky chart (there are apps for that) to orient yourself in the sky, observe. So, compare the visibility of some of themwith or without some astronomical instrument with the images captured by Hubble and beautifully processed by scientists.

Caldwell 51. (NASA, ESA, and J. Holtzman (New Mexico State University); Processing: Gladys Kober (NASA/Catholic University of America)).

"These images were taken by Hubble throughout its career and used for scientific research or engineering tests, but NASA had not fully processed the images for public release until now," NASA says.

Catalogues and more catalogues

All the new images are part of a catalog called the Caldwell catalog. In short, there are countless astronomical catalogs. You've probably seen some space object called Messier (or just the letter M) or NGC, followed by a series of numbers. These are the object identifications in the catalogs.

The Messier catalog was born from a compilation made by the French astronomer Charles Messier between 1764 and 1781. It includes a total of 110 objects: 40 are galaxies, 29 globular clusters, 27 open clusters, and 11 nebulae (6 diffuse, 4 planetary, and one supernova remnant).

The NGC (New General Catalogue) was created by John Dreyer. With 7840 objects, the NGC was born to replace and complement a previous deep space catalog, the Catalog of Nebulae and Star Clusters (CN). In this way, later, Dreyer also published the Index Catalogues, Since then, the NGC has gone through several revisions.

Caldwell 36. (NASA, ESA, and S. Smartt (The Queen's University of Belfast); Processing: Gladys Kober (NASA/Catholic University of America)).

The Caldwell catalog

The Caldwell Catalog, then, is one of those countless lists of astronomical objects. The list is named after its creator, the famous amateur astronomer Sir Patrick Caldwell-Moore, who died in 2012 at the age of 89. He worked in radio, television, wrote fictional works and science popularization texts, and was a veteran of World War II.

Caldwell published his catalog in 1995 in Sky & Telescope magazine. He created it as a complement to the Messier catalog. Of the 109 objects, none are in the Messier catalog, and they are bright enough for any amateur astronomer to see without fancy astronomical equipment.

Another point Caldwell paid attention to was encompassing the world. In his catalog, he divided the list between the southern and northern hemispheres, since each portion of the globe sees the sky differently from the other. This way, an observer anywhere on the globe can be guided through his catalog.

Caldwell 29. (NASA, ESA, and L. Ho (Peking University); Processing: Gladys Kober (NASA/Catholic University of America)).

Access the full list of Hubble's birthday celebration images through this link.

With information from NASA.