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.

2023 May 9
A sunset sky over Sicily is shown with, from top to bottom, a pink 
atmospheric band, a blue atmospheric band containing the Moon, a band
with land containing buildings, and a band of water reflecting the 
pink and blue atmospheric bands.
Please see the explanation for more detailed information.

Shadows of Earth
Image Credit & Copyright: Marcella Giulia Pace

Explanation: Can you find two Earth shadows in today's image? It's a bit tricky. To find the first shadow, observe that the top part of the atmosphere appears pink and the lower part appears blue. This is because the top half is exposed to direct sunlight, while the lower part is not. The purple area in between is known as the Belt of Venus, even though Venus can only appear on the other side of the sky, near the Sun. The blue color of the lower atmosphere is caused by the Earth blocking sunlight, creating Earth shadow number 1. Now, where is the second Earth shadow? Take a look at the Moon. Do you notice something unusual about the lower left part? That area appears unusually dark because it is in the shadow of the Earth, creating Earth shadow number 2. To be precise, the Moon was captured during a lunar eclipse. This carefully timed image was taken in Sampieri, Sicily, Italy, in July 2018.

Tomorrow's picture: desert galaxy


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