Astronomy Picture of the Day · July 17, 2021

Alphonsus and Arzachel

The Astronomy Picture of the Day for July 17, 2021 is “Alphonsus and Arzachel,” an image. The picture is copyrighted by its creator (Image Credit & Copyright: Noel Donnard). The original explanation runs about 136 words.

From the explanation

“Point your telescope at tonight’s first quarter Moon. Along the terminator , the shadow line between night and day, you might find these two large craters staring back at you with an owlish gaze.”

— APOD editors, July 17, 2021

Read the full explanation on science.nasa.gov

At a glance

Date: July 17, 2021
Type: Image
Credit: Credit: Image Credit & Copyright: Noel Donnard
Copyright: Copyrighted by the credited creator. Ask the copyright holder before reusing it.
Explanation length: About 136 words

All of July 2021 → · 2021 by month → · Full archive since 1995 →

Topics in this entry

The Moon

Topics are matched from words in the title and explanation.

On this day: July 17 in other years

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Source

Astronomy Picture of the Day, July 17, 2021 — science.nasa.gov/image-article/apod-2021-july-17-alphonsus-and-arzachel

Copy taken Oct 28, 2026, 2:39 AM EDT. The image and explanation belong to their creators. OpenOrbit is not affiliated with or endorsed by NASA.