Galileo discovered Europa, Jupiter’s fourth-largest moon, in 1610. In 1977, the Voyager spacecraft buzzed past and we realized it was covered in ice. It took a few more years to understand that it also likely had unfrozen liquid water oceans. Kevin Hand, Deputy Project Scientist for the Europa mission at NASA’s Jet Propulsion Lab (JPL) explains how his team plans to launch a series of missions to orbit, land on, and hopefully explore the curious moon’s deep salty oceans with a self-driving space submarine. And Tom Cwik, manager for JPL’s space technology program, describes how he looks to Earth-bound submarines, ice drills and self-driving cars for inspiration of how to explore this distant world.

In 1985, the British Antarctic Survey discovered something that shocked scientists around the world: the ozone layer had a hole in it. And the hole was growing very quickly. When they were presented with the problem, politicians and world leaders quickly came up with an international agreement to immediately reduce chlorofluorocarbons released into the atmosphere. It was a success story, and we can learn from it on climate change.

Going to Mars is hot right now, just ask Matt Damon. But would you go if you knew your bones would turn into something called "pee brittle"?

Former astronaut Michael Massimino reveals the uncomfortable side of liftoff. And Dr. Jennifer Fogarty from NASA's Human Research Program elaborates on the physical challenges humans face with longterm weightlessness.

An Orbital Path episode all about...an orbital path! Planet 9's, to be exact. The replacement for Pluto as our solar system's ninth planet is out there somewhere, and astronomers can see the ripples it creates, especially at this time of year.

Scientific discovery can happen in two ways: "Eureka!" moments of sudden understanding, where researchers glean unexpected insight into new phenomena. Or, a slower, less glamorous hunt for truth that happens day-after-day, for years. But both methods can lead to new understandings that pushes the field forward for future breakthroughs. In this episode: the sudden realization that led to the discovery of the first ever black hole, and another more methodical search for the moment that a star dies and a black hole is born.

The sun can seem like a friendly celestial body. But just as sun decided when life on Earth could begin, it will also decide when life on Earth will definitely end. We'll hear about the impressive fleet of spacecraft NASA uses to monitor the Sun, including the upcoming Solar Probe Plus, an exciting new mission to delve closer to our star than ever before.

When Proxima b's discovery appeared in Nature on August 24, the media breathlessly announced a new Earth-like planet just 4.2 light years away from Earth.

Astronomers have, for years, anticipated a planet orbiting Proxima Centauri. Michelle Thaller talks with astrophysicist Dr. Patricia Boyd about NASA’s ongoing search for exoplanets and what’s the next step in human exploration of other worlds.

The asteroid belt is portrayed in movies as a crowded place with massive rocks bouncing each other like pool balls, capable of sending a mile-wide missile hurtling toward Earth at any moment. The reality is much more fascinating. Host Dr. Michelle Thaller speaks with Dr. Lucy McFadden, Co-Investigator of NASA’s Dawn Mission to orbit the asteroids Vesta and Ceres. She shares what they’ve learned by traveling 130 million miles to visit places we’ve always viewed from afar.

Michael Kentrianakis loves eclipses and has seen them from all over the world. Host Michelle Thaller and Mike talk about the stages of the eclipse we can see in his video that went viral few months ago after an Alaska Airlines flight. That flight was diverted for better eclipse viewing thanks to Joe Rao, who has convinced airlines to do this before. We'll hear how he pulled it off We'll hear how he pulled it off and learn where best to view the August 21, 2017 total solar eclipse.

From space, the view of earth has no boundaries for countries, no barriers to achievement. Michelle Thaller speaks with Aprille Ericcson, a senior engineer at NASA, about her career path and about current challenges recruiting more women and minorities into engineering and space science.

Orbital Path is hosted by astronomer Michelle Thaller and produced by Lauren Ober. Learn more about them here.