Stickney Crater: how close Phobos came to destruction
On October 9, 2026, NASA's Astronomy Picture of the Day (APOD) — a long-running program that pairs a daily image of the universe with commentary from a professional astronomer — turned its focus to Stickney Crater, the dominant surface feature of Phobos, the larger of Mars's two moons.
Spanning roughly 9 kilometers across, Stickney is a remarkable formation given that Phobos itself measures only about 22 kilometers at its widest point. The impact event that carved out the crater is thought to have come close to shattering the moon entirely. Linear grooves radiating outward from the crater's rim are interpreted as fractures caused by the enormous stress of that ancient collision.
Phobos is increasingly regarded as a high-priority destination in planetary science. JAXA's Martian Moons eXploration mission, known as MMX, aims to land on Phobos and return surface samples to Earth by around 2031. One of the central questions the mission hopes to address is whether Phobos is a captured asteroid or a remnant of a massive impact on Mars itself — a distinction with significant implications for the early history of the inner solar system.
Saturn's crowded neighborhood
The previous day's APOD, published on October 8, offered an entirely different scale of perspective. A composite image of the Saturnian system — dubbed a smörgåsbord in reference to its visual abundance — brought together the planet, its iconic rings, and several of its moons in a single frame.
Saturn currently holds the record for the most confirmed moons in the solar system, with more than 140 catalogued to date. Two of them dominate scientific discussion: Titan, whose surface is laced with lakes and rivers of liquid methane and ethane, and Enceladus, which vents plumes of water vapor from a subsurface ocean. NASA's Dragonfly mission, scheduled for launch in 2028, will send a rotorcraft to Titan to investigate its complex organic chemistry.
Many of the most striking images of Saturn continue to draw on the archive of the Cassini spacecraft, which orbited the planet from 2004 until its controlled atmospheric entry in 2017. Years after the mission's end, that dataset remains a productive source for both scientific publications and public outreach.
ESA's weekly window on space
Meanwhile, the European Space Agency published its regular week-in-images roundup covering October 5 through 9, 2026. The selection typically draws from across ESA's portfolio: Earth observation data from the Sentinel satellites under the Copernicus program, deep-space imagery from missions such as the Euclid telescope, and updates from active probes elsewhere in the solar system.
These weekly releases serve a purpose beyond aesthetics. By bringing spacecraft data into public view on a consistent basis, agencies like ESA and NASA help maintain a broader understanding of just how active — and how productive — current space exploration actually is. Dozens of missions are operating simultaneously at any given moment, generating data that will inform research for decades.
Whether it is an ancient impact scar on a Martian moon, the intricate architecture of Saturn's rings, or a storm system photographed from low Earth orbit, each image asks the same underlying question: what else is out there, and when do we go?
