On January 17, 2025, NASA announced the release of an expanded gigapixel mosaic of the Andromeda Galaxy, a decade after the original was published. The new image, created from over ten years of observations by the Hubble Space Telescope, showcases approximately 200 million stars within a 2.5 billion pixel frame, significantly surpassing the previous record.
The immense data size of the mosaic has led NASA to provide a lower-resolution version, still exceeding 700 megabytes, for public download. Access to the original high-resolution files is available through a dedicated astronomical imaging platform.
The creation of this expansive panorama involved a substantial effort from the Hubble team, capturing various sections of the galaxy over the years. Hubble's capabilities allow it to resolve stars brighter than our Sun; however, the majority of Andromeda's estimated trillion stars remain too dim for Hubble to detect.
This unveiling serves as a reminder of Edwin Hubble's pivotal discovery a century ago, which established that the universe is larger than the Milky Way. His observations of Andromeda revolutionized cosmology, revealing an infinitely larger cosmos.
The new mosaic, titled “Hubble M31 PHAT+PHAST Mosaic,” incorporates data from the Panchromatic Hubble Andromeda Southern Treasury (PHAST) program, complementing the earlier Panchromatic Hubble Andromeda Treasury (PHAT) project.
For those interested, a version of the mosaic with a resolution of 42,208×9,870 pixels is available for download directly from NASA, while original files can be accessed through the NASA Space Telescope Archive.