NASA Hubble's most detailed image reveals Andromeda galaxy's hidden history

Andromeda Galaxy (Image: Canva)

The Andromeda galaxy, the closest large galaxy to Earth, has intrigued astronomers for over a century. A new study by NASA's Hubble Space Telescope reveals stunning details about this cosmic neighbour. The research helps explain Andromeda’s complex evolution and its differences from the Milky Way.

A Detailed Look at Andromeda's Structure

In the latest study, Hubble's sharp imaging uncovered more than 200 million stars in Andromeda. This marks the most detailed survey of the galaxy, which lies 2.5 million light-years away. Hubble’s data spans the entire disk of Andromeda, offering a clear view of its stellar population. The telescope’s capabilities allow it to study stars brighter than our Sun.

This is the largest photomosaic ever made by the Hubble Space Telescope. The target is the vast Andromeda galaxy that is only 2.5 million light-years from Earth, making it the nearest galaxy to our own Milky Way. Andromeda is seen almost edge-on, tilted by 77 degrees relative to Earth’s view. (Image: NASA)

However, Andromeda has around 1 trillion stars. Many of these are less massive and beyond Hubble’s sensitivity range. The galaxy is significantly larger than others observed by Hubble, making it a challenging subject for the telescope.

Tracking Andromeda's Merger History

Researchers believe Andromeda has a rich merger history. It displays many young stars and coherent star streams, indicating active star formation. "Andromeda looks like a transitional galaxy," said Daniel Weisz from the University of California. "It’s between a star-forming spiral and an elliptical galaxy."

One possible cause for this is a past collision with the nearby Messier 32 galaxy. This interaction may have depleted Andromeda’s interstellar gas, slowing star formation. Studies suggest that Andromeda's unique structure is the result of this event.

Hubble’s data will help future telescopes, like NASA's James Webb Space Telescope and the Nancy Grace Roman Space Telescope, explore these findings further. These telescopes will provide even more clarity on Andromeda’s past and its connection to the Milky Way.