Planetary Picture of the Day Week of May 12, 2025

Yes, you are seeing double in this beautiful photograph from Josh Dury, taken last week from Mendip Hills in Somerset, UK. This particular phenomenon is called a parhelic circle—an optical phenomenon appearing as a white line at the same altitude as the Sun. Parhelic circles form as beams of sunlight are reflected by vertical or almost vertical hexagonal ice crystals. In rare instances, a complete circle stretches across the sky, which it did here. This image captures a nearly 180-degree portion of the sky, horizon to horizon.

Did you know that Mars has an atmosphere? It's very thin and not breathable for humans, but it does have wind and can carry dust around the planet. This image, captured by ESA's Mars Express, shows that thin atmosphere, fading away into the darkness of space. Also shown is Promethei Terra, a large region to the east of the massive impact basin Hellas Planitia.

The graceful, winding arms of the majestic spiral galaxy M51 (NGC 5194) appear like a grand spiral staircase sweeping through space. They are actually long lanes of stars and gas laced with dust.

This sharpest-ever image, taken in January 2005 with the Advanced Camera for Surveys aboard the NASA/ESA Hubble Space Telescope, illustrates a spiral galaxy's grand design, from its curving spiral arms, where young stars reside, to its yellowish central core, a home of older stars. The galaxy is nicknamed the Whirlpool because of its swirling structure.

The Whirlpool is one of astronomy's galactic darlings. Located approximately 25 million light-years away in the constellation Canes Venatici (the Hunting Dogs), the Whirlpool's beautiful face-on view and closeness to Earth allow astronomers to study a classic spiral galaxy's structure and star-forming processes.

Rise and shine! Firefly Aerospace’s Blue Ghost lander captured a stunning sunrise over the lunar surface on March 3. The lander carried ten scientific instruments onboard, all of which operated successfully for a full two weeks. At that time, the lander rotated into lunar night and ran out of battery power.