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 September 25
A sunrise sky is shown over water and trees. The horizon
is orange and the top of the image is deep blue. On the far 
right vertical bands are shown becoming progressively darker. 
In each band a comet appears, with the comet appearing 
increasingly near the top of the image on lighter bands.
The main part of the image on the left is the lightest. 
Please see the explanation for more detailed information.

Comet A3 Through an Australian Sunrise
Image Credit & Copyright: Lucy Yunxi Hu

Explanation: Comet Tsuchinshan-ATLAS is now visible in the early morning sky. Diving into the inner Solar System at an odd angle, this large dirty iceberg will pass its closest to the Sun -- between the orbits of Mercury and Venus -- in just two days. Long camera exposures are now capturing C/2023 A3 (Tsuchinshan–ATLAS), sometimes abbreviated as just A3, and its dust tail before and during sunrise. The featured image composite was taken four days ago and captured the comet as it rose above Lake George, NSW, Australia. Vertical bands further left are images of the comet as the rising Sun made the predawn sky increasingly bright and colorful. Just how bright the comet will become over the next month is currently unknown as it involves how much gas and dust the comet's nucleus will expel. Optimistic skywatchers are hoping for a great show where Tsuchinshan–ATLAS creates dust and ion tails visible across Earth's sky and becomes known as the Great Comet of 2024.

Survey: Color Blindness and Astronomical Images
Growing Gallery: Comet Tsuchinsan-ATLAS in 2024
Tomorrow's picture: open space


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