Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2024 August 7
A starry sky is seen through a rectangular rock opening. Three rocky peaks appear toward the right, while other peaks appear toward the left. Rising above the right peaks is the central band of our Milky Way Galaxy. Please see the explanation for more detailed information.

Milky Way Behind Three Merlons
Image Credit & Copyright: Donato Lioce; Text: Natalia Lewandowska (SUNY Oswego)

Explanation: To some, they look like battlements, here protecting us against the center of the Milky Way. The Three Merlons, also called the Three Peaks of Lavaredo, stand tall today because they are made of dense dolomite rock which has better resisted erosion than surrounding softer rock. They formed about 250 million years ago and so are comparable in age with one of the great extinctions of life on Earth. A leading hypothesis is that this great extinction was triggered by an asteroid about 10-km across, larger in size than Mount Everest, impacting the Earth. Humans have gazed up at the stars in the Milky Way and beyond for centuries, making these battlefield-like formations, based in the Sexten Dolomites, a popular place for current and ancient astronomers.

Tomorrow's picture: open space

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