Articles

Stories, updates, insights, and original analysis from The Planetary Society.

Galileo's highest-resolution images of Jupiter's ringmoons

Galileo's best pictures of Jupiter's ringmoons

People often ask me to produce one of my scale-comparison montages featuring the small moons of the outer solar system. I'd love to do that, but Galileo's best images of Jupiter's ringmoons lack detail compared to Cassini's images from Saturn.

New Robotic Spacecraft Posters

Another round of posters to celebrate historic planetary missions.

Jupiter's changing face, 2009-2015

Damian Peach's photo-documentation of Jupiter helps us monitor the giant planet's ever-changing patterns of belts, zones, storms, and barges, during a time when no orbiting missions are there to take pictures.

New Horizons is a Triumph for Space Advocates

New Horizons—what will be NASA’s greatest success of 2015—was cancelled multiple times in its early life, and many times before that in its previous incarnations. A mission to Pluto was not inevitable, despite the overwhelming scientific and public excitement.

NASA Goes First Class for Europa

Over the last several years, engineers at the Jet Propulsion Laboratory and Applied Physics Laboratory have rethought the entire approach to exploring Europa. NASA now has a concept that's affordable.

Announcing the Europa Science Instruments

Why We Don't Know When the Europa Mission Will Launch

NASA has been vague about when the new mission to Europa will launch. There's a reason for that, and it's not just orbital mechanics.

Here Are the Science Instruments NASA Will Use to Explore Europa

NASA just announced the science instruments that will be used to understand the enigmatic ocean moon of Europa. The mission is planned to launch sometime in the early 2020s.

Looking Down On Jupiter's North Pole

Ted Stryk shares the most direct view of a Jovian pole ever captured by a spacecraft.

Europa as imaged by NASA's Galileo spacecraft in the 1990s

NASA's Mission to Europa May Get More Interesting Still

NASA officials have asked their European counterparts if they would like to propose contributing a small probe to NASA's Europa mission planned for the mid-2020s.

Global color view of Titan with a polar hood (7 December 2011)

A moon with atmosphere

What is the solar system moon with the densest atmosphere? Most space fans know that the answer is Titan. A few of you might know that Triton's is the next densest. But what's the third? Fourth? Do any other moons even have atmospheres? In fact, they do; and one such atmosphere has just been discovered.

Global Saturnshine view of Enceladus in color

Four Ideas to Bust the Floor on Outer Planet Mission Costs

The road to lower costs outer planet missions has been paved by NASA’s first two New Frontiers missions, the $700M New Horizons mission to Pluto and the $1.1B Juno mission to Jupiter. But can the cost of a mission to the outer solar system be cut to $450M, the limit for a Discovery mission?

Interiors of icy bodies in the solar system (as of 2010)

An internal ocean on Ganymede: Hooray for consistency with previous results!

A newly published paper confirms a subsurface ocean at Ganymede. An ocean there was already suspected from its magnetic field and predicted by geophysics; new Hubble data confirms it, and even says it is in the same place we thought it was before. Such consistency is rare enough in planetary science to be worth celebration.