Astronomy Picture of the Day · July 23, 1999

A Martian Valley

The Astronomy Picture of the Day for July 23, 1999 is “A Martian Valley,” an image. It is credited to Credit: Malin Space Science Systems, MGS, JPL, NASA. The original explanation runs about 73 words.

From the explanation

“This tantalizing close-up detail of a network of martian valleys was recorded from orbit this April by Mars Global Surveyor’s camera. Water may once have flowed here but now sand dunes stripe the windswept valley floor.”

— APOD editors, July 23, 1999

Read the full explanation on science.nasa.gov

At a glance

Date: July 23, 1999
Type: Image
Credit: Credit: Malin Space Science Systems, MGS, JPL, NASA
Copyright: No copyright notice on the entry. Check the credited institution’s own usage rules before reusing it.
Explanation length: About 73 words

All of July 1999 → · 1999 by month → · Full archive since 1995 →

Topics in this entry

Mars

Topics are matched from words in the title and explanation.

On this day: July 23 in other years

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Source

Astronomy Picture of the Day, July 23, 1999 — science.nasa.gov/image-article/apod-1999-july-23-a-martian-valley

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.