Astronomy: New Discovery Reveals Recent Collision in Milky Way’s History

This article discusses a recent discovery that suggests the last major collision in our Milky Way happened much later than previously thought. Analysis of data from ESA’s Gaia space telescope by researchers at Rensselaer Polytechnic Institute in the USA indicates that the distortions in the distribution of stars in the Milky Way point to a collision that occurred only three billion years ago. This finding challenges the previous assumption that the collision happened much earlier.

The research team found evidence of this more recent collision in the vast amount of data collected by the Gaia space telescope, which has been studying stars in our galaxy for years. By examining around 100,000 nearby objects, they observed “wrinkles” in the distribution of stars, indicating a recent disturbance in the galaxy’s structure.

Previously, the last known collision in the Milky Way was believed to be the Gaia-Sausage-Enceladus (GSE) collision, estimated to have occurred around five to eight billion years ago. The new discovery, which does not yet have a specific name, is linked to an event known as the “Virgo Radial Merger”, dated three billion years ago.

This finding highlights the gaps in our understanding of the Milky Way’s history and underscores the importance of the Gaia space telescope in unraveling these mysteries. The research has been published in the Monthly Notices of the Royal Astronomical Society.