Mars and Phobos (annotated)

This pair of NASA/ESA Hubble Space Telescope images of Mars taken on 28 December (top) and 29 December (bottom) 2024. Each image shows a different side of the planet, with the accompanying moon Phobos. Various features are identified in the images, including the polar ice caps and clouds, as well as multiple terrestrial features.

At the midpoint of the observations, Mars was approximately 98 million kilometres from Earth. Thin water-ice clouds that are apparent in ultraviolet light give the Red Planet a frosty appearance. The icy northern polar cap was experiencing the start of Martian spring. 

In the top image, the bright orange Tharsis plateau is visible with its chain of dormant volcanoes. The largest volcano, Olympus Mons, pokes above the clouds at the 10 o’clock position near the northwest limb. At an elevation of over 21 000 meters, it is 2.5 times the height of Mt. Everest above sea level. Valles Marineris, Mars’ over 4,000-kilometre-long canyon system, is a dark, linear, horizontal feature near center left. 

In the bottom image, high-altitude evening clouds can be seen along the planet’s eastern limb. The 2,250-kilometre-wide Hellas basin, an ancient asteroid impact feature, appears far to the south. Most of the hemisphere is dominated by the classical “shark fin” feature, Syrtis Major.

[Image description: Two views of Mars. Top left text: Mars & Phobos, Hubble Space Telescope; filters in colors: F275W, purple; F410M, blue; F502N, green; F673N, red. Top image: December 28, 2024 20:00 UT. Most of the planet is shades of orange. The brightest orange area on the left half. At the top and bottom, white polar caps. Limb is blue. Text top center: northern polar cap, clouds. On planet, top to bottom, left to right: Arcadia Planitia, Tempe Terra, Acidalia Planitia; Olympus Monds; Tharsis Montes, Chryse Planitia; Valles Marineris, Terra Meridiana; Solus Planum; Argyre Planitia, Noachis Terra. To the right, dot: Phobos. Lower image: December 29, 2024 13:18 UT. Compass arrows at right, north pointing up, = east left. The planet has similar features; the brightest orange area is two centered two blobs. Text above Mars: northern polar cap, clouds. On-planet: Utopia Planitia; Arabia Terra, Syrtis Major; Terra Meridiani, Schiaparelli Crater, clouds; Noachis Terra, Huygens Crater, Syrtis Minor; Hellas Planitia. At left, dot: Phobos.]