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The Downlink • Aug 28, 2026
Size is in the eye of the beholder
Space Snapshot
Perseverance’s main job is to study things on the Martian surface, but it’s always worth looking up. Earlier this month, the NASA rover captured this view of Mars’ tiny moon Phobos passing in front of the Sun. Image credit: NASA/JPL-Caltech/ASU/MSSS/SSI.
Fact Worth Sharing
If Phobos orbited a few thousand kilometers closer to Mars, its apparent size from the surface could be enough to create a total solar eclipse. Although Phobos is getting closer to Mars with time, tidal forces are expected to rip it apart before it gets close enough to eclipse the Sun completely.
Mission Briefings
The Nancy Grace Roman Space Telescope is preparing to launch. On Sunday, Aug. 30, the next-generation observatory will launch to begin its mission to transform our understanding of dark energy and exoplanets. On this week’s Planetary Radio, hear from Julie McEnery, senior project scientist for Roman at NASA Goddard, and Jason Rhodes, project scientist for Roman at JPL, about what's ahead. Pictured: Roman being encapsulated in the payload fairing ahead of mating to a SpaceX Falcon Heavy rocket. Image credit: NASA/Sydney Rohde (Rocz).
Human-related microbes could survive on the Moon’s south pole. A new study suggests that some microbes that live on humans can survive the conditions found in some shadowed areas near the lunar south pole. Because this area is where the Artemis IV mission aims to land, the study seeks to understand how potential contamination could interfere with science goals.
Bad weather has delayed China’s Chang’e-7 mission. A powerful tropical storm has forced the Chinese space agency to postpone the launch of the lunar mission, possibly until 2027. Chang’e-7 aims to seek out water ice on the Moon using a combination of orbiting, landing, roving, and hopping spacecraft.
From The Planetary Society
What could Artemis IV astronauts discover on the Moon? When NASA sends humans back to the lunar surface, those astronauts will have opportunities to conduct valuable science. Researchers on the ground are already preparing to make the most of this opportunity. Here are some of the scientific mysteries Artemis IV could help solve. Pictured: Apollo 15 commander David Scott deploying a scientific instrument on the Moon in 1971. Image credit: NASA.
Ever wanted to have dinner with an astronaut? NASA astronaut and former International Space Station commander Leroy Chiao will join Planetary Society book club members next week for a live virtual discussion of his memoir, “Dinner with an Astronaut.” This event is exclusive to Planetary Society members. Not yet a member? Join today.
The Sun shines brightly until it doesn’t. This is how Planetary Society Chief of Space Advocacy Casey Dreier describes the surreal suddenness of the total solar eclipse he witnessed in Spain. Read his stirring description of the eclipse in this month’s Space Advocate newsletter.
We still need you to speak up for science. The manner in which science is funded in the United States is still being decided in Congress, and your voice matters. The proposed rule changes would give political appointees — not scientists — the power to decide which science grants get funding. The Senate has voted against this change, but the House of Representatives has yet to agree. Join us in advocating to Congress for the protection of science.
What's Up
This week, Saturn rises in the east at dusk and crosses the sky through the night, joined by the Moon on Aug. 29 and 30. In the predawn, look for reddish Mars in the east with bright Jupiter closer to the eastern horizon. Learn more in our guide to the night sky.
Join now and save space missions
If you are not one already, become a member TODAY and help shape the future of space science and exploration by fueling mission-critical advocacy efforts. Here’s just one example: The Planetary Society led efforts in Washington to Save NASA Science in 2026. Thanks to the support of our members, we were able to prevent an extinction-level budget cut to planetary exploration this year. This means more missions, more science, and exploration in our Solar System.
Will you join us and protect the future of exploration?
Wow of the Week
This photo of the fairing that contains the Nancy Grace Roman Space Telescope creates an illusion of scale — the fairing looks as tall as the building beside it. In fact, that structure is the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center, and it is truly enormous. The VAB is designed to assemble rockets vertically in preparation for launch, and is the largest single-story building in the world. Image credit: NASA/Sydney Rohde (Rocz).
Send us your artwork!
We love to feature space artwork in the Downlink. If you create any kind of space-related art, we invite you to send it to us by replying to any Downlink email or writing to [email protected]. Please let us know in your email if you’re a Planetary Society member!