The DownlinkAug 20, 2021

Proximity and distance

Space Snapshot

Watson view of drill hole

Impact crater? Ancient volcano? What may at first look like a large feature in this recent image of Mars is in fact a close-up of the first borehole drilled by NASA’s Perseverance rover. The rover took this image at night using an LED light to control shadows, adding to the visual confusion of scale. Image credit: NASA/JPL-Caltech/MSSS.

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Fact Worth Sharing

Earth illustration

NASA’s Voyager 2 spacecraft launched 44 years ago today, on August 20, 1977. Voyager 1 took off 16 days later but reached a higher velocity and eventually overtook its sister spacecraft. Voyager 1 is now the most distant object ever sent from Earth.

Mission Briefings

Phobos up close

Was there ever life on Phobos? A new study from Japan Aerospace Exploration Agency (JAXA) researchers suggests that ancient asteroids could have blasted material containing life off Mars’ surface, and that the material could have settled on Phobos. The researchers note that any Martian life that survived the trip would long be extinct by now. JAXA’s Martian Moons eXploration (MMX) mission could provide some clarity — it’ll launch in 2024 to study both Martian moons, eventually returning a sample of Phobos to Earth in 2029. Pictured: This image of Phobos was taken by NASA's Viking 1 spacecraft in 1978. Image credit: NASA/JPL-Caltech.


Blue Origin has filed a suit against NASA over its lunar lander contract. Though specifics of the lawsuit are still sealed, Blue Origin said in a statement that it was attempting to “remedy the flaws in the acquisition process found in NASA's Human Landing System.” Blue Origin filed a protest with the Government Accountability Office (GAO) in April after NASA chose SpaceX as the sole recipient of its Human Landing System contract; in July, that objection was denied after the GAO concluded NASA’s selection process was fair.


Get ready for lots of spacewalks in the coming weeks. On August 24, commander Akihiko Hoshide and flight engineer Mark Vande Hei will prepare the International Space Station for an upcoming SpaceX Cargo Dragon mission. In early September, Cosmonauts Oleg Novitskiy and Pyotr Dubrov will go on two spacewalks to assemble equipment for the Nauka Multipurpose Laboratory Module, which docked at the ISS in July.

From The Planetary Society

Juice targets
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Jupiter’s icy moons are among the top destinations in the search for life. Callisto, Ganymede and Europa (pictured) all show hints of liquid water oceans beneath their crusts. On Earth, life thrives in the deepest, darkest parts of our oceans near hydrothermal vents. Could life similarly evolve or survive on the ocean floors of these moons? See our guide to the European Space Agency’s JUICE mission to learn how the spacecraft will investigate these enigmatic worlds. Pictured: NASA's Galileo spacecraft captured these images of the Jovian moons in 1997 and 1998. Image credit: NASA/JPL/Ted Stryk.

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Jupiter’s moons may hint at habitability, but Saturn will not be outshone! Data from NASA’s Cassini mission to the ringed world are still being processed four years after the mission ended, and suggest that Saturn’s moon Enceladus may be another potential home for microbial life. Cassini project scientist Linda Spilker joins this week’s Planetary Radio to talk about some intriguing new findings, her role with the Voyager mission, and much more.

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We know we want to visit far-flung worlds, but how do we get there? The latest article from Planetary Society chief advocate Casey Dreier lays out the importance of Plutonium-238 as an essential power source for spacecraft that venture to distant places where solar power is less reliable. Although this non-weapons-grade radioactive material is important for space exploration, its production on Earth hasn’t always been sustained. Planetary Society advocacy has helped ensure that we never run out.

What's Up

Jupiter illustration

In the early evening look for super-bright Venus in the west. You’ll also find Jupiter and Saturn in the east, shining brightly in proximity to the Moon. Learn more at

You’re Invited!

Crowd lightsail launch

Join our CEO Bill Nye for a live virtual premiere of “Sailing the Light,” a short documentary about LightSail 2, the groundbreaking solar sailing mission funded by people like you from around the world. Following the film, Bill and mission team members will answer your questions live. You don’t want to miss it, so set your reminders now! The show starts Saturday, August 28 at 1 p.m. ET (17:00 UTC) on YouTube Live. Pictured: LightSail 2 supporters watching their spacecraft launch in 2019. Image credit: Navid Baraty/The Planetary Society.

Wow of the Week

Enceladus closeup

At first glance this image looks like a microscopic view of some familiar texture like leather. But in another example of disorienting perspective, this rippled surface is actually Saturn’s moon Enceladus in a composite of images taken by NASA’s Cassini spacecraft from a distance. The wrinkles you see here are ridges in the icy crust of Enceladus’ south pole, where cracks in the ice vent water out into space. Image credit: NASA et al.