Into the Past: Milky Way Mosaic

December 10, 2020



Image Creators: Tomas Slovinsky; Petr Horalek
Summary Authors: Tomas Slovinsky; Petr Horalek

This mosaic of the Milky Way isn’t what you might think at the first look. It’s actually a photographic mirror to the past. One of the factors that determine how the view of the night sky changes over the eons is the Earth’s axial precession, the gradual shift in the orientation of Earth’s axis of rotation that occurs in a cycle of approximately 25,772 years. What we're demonstrating here is how the visibility of particular parts of the sky change as the position of the celestial pole shifts

The top portion of this nighttime sky-view was taken in May 2020, from Runina, Slovak Republic (49 degrees north latitude); whereas the bottom portion was taken in April 2019, from the Maldives island of Soneva Fushi (5 degrees north latitude). This bottom portion then shows what could have been seen at night almost 8,000 years ago from present-day Slovakia, when the position of the North Celestial Pole was considerably different. Back in the past, even the Southern Cross or Crux (see annotated image) was easily visible from the mid-latitudes of the northern hemisphere.