And this episode marks the end of Orbital Path.

So, for the last transit of our podcast, Dr. Michelle Thaller and producer David Schulman join NASA astrobiologist Dr. Jen Eigenbrode on a site visit to one of Michelle’s very favorite places at Goddard Space Flight Center. It’s building 29, where NASA builds and tests spacecraft in some of the most extreme conditions found anywhere on earth. 

Orbital Path is produced by David Schulman. 




Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.




Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: NASA

Sixty-five million years ago, an asteroid crashed into the Yucatán. The impact caused apocalyptic tsunamis and volcanic eruptions. Grit and ash blotted out the sun. It wiped out species that had roamed the Earth for millions of years.

Yet asteroid hits also were critical to the origins of life on Earth. Asteroids may well have been the bringers of water, of carbon, even of amino acids — the building blocks of life.

That’s a big reason why NASA is on a mission to Bennu. This asteroid is like an ancient fossil of our solar system — largely unchanged since the time the planets formed.

In December, after a billion-mile journey, NASA’s Osiris-Rex mission arrives at Bennu. And, for the first time, a spacecraft will try to actually bring back an asteroid sample to Earth.

On this episode of Orbital Path, Dr. Michelle Thaller sits down with Dr. Amy Simon — a senior scientist at NASA’s Goddard Space Flight Center, and a key player on the Osiris-Rex mission. Michelle and Amy talk about the mission, Amy’s work to probe the origins of the solar system, and one other thing: 

The remote chance that Bennu, someday, could collide with Earth.

Orbital Path is produced by David Schulman. 

Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: NASA/Goddard/University of Arizona.

Start with a star much bigger than the sun — the bigger the better. Then settle in, and wait a few million years for your star to die.

That should do the trick, if you want to get yourself a garden-variety black hole. But there’s another kind of black hole. They are mind-boggling in size. And deeply mysterious:

Super-massive black holes.

Last year, in the journal Nature, a team of astronomers reported finding one with the mass of 800 million suns. It’s the most distant black hole in the known universe. And it’s so ancient, it dates to a time when it seems light itself was only just beginning to move.

On this episode of Orbital Path, Dr. Michelle Thaller talks with astrophysicist Chiara Mingarelli — Flatiron Research Fellow at the Center for Computational Astrophysics in New York. Using a special gravitational wave observatory, Dr. Mingarelli is part of a cadre of astronomers hoping ancient super-massive black holes will soon reveal mysteries dating to the dawn of our universe.

Orbital Path is produced by David Schulman.

Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: NASA artist’s rendering of a super-massive black hole.

Orbital Path is produced by David Schulman.

Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: NASA



Our world makes sense thanks to mathematics. Math lets us count our livestock, it lets us navigate our journeys. Mathematics has also proved an uncanny, stunningly accurate guide to what Brian Greene calls “the dark corners of reality.”



But what happens when math takes us far, far beyond what we — as humans — are equipped to perceive with our senses? What does it mean when mathematics tells us, in no uncertain terms, that the world exists not in three, not in four — but in no fewer than 11 dimensions?



In this encore episode of Orbital Path (previously heard in October 2017), Brian Greene, a celebrated explainer of how our universe operates and the director of the Center for Theoretical Physics at Columbia University, sits down to talk with Dr. Michelle Thaller. 

Together they dig into the question of how we — as three-dimensional creatures — can come to terms with all those extra dimensions all around us. 


Orbital Path is produced by David Schulman. Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image by: World Science Festival / Greg Kessler

And he should know.

Susskind is a grandee of theoretical physics. In the 1960s, he was one of the discoverers of String Theory. His friends and collaborators over the years include the likes of Nobel Prize winners Gerard ‘t Hooft and Richard Feynman.

And, for more than a decade, Susskind engaged in an intellectual clash of the Titans with Stephen Hawking — and came out on top.

On this episode of Orbital Path, Dr. Michelle Thaller talks with Susskind about his extraordinary life in physics. And Susskind offers a tantalizing glimpse into his recent work on the holographic principle, which suggests our universe may be a far, far stranger place than humans have yet imagined.

Orbital Path is produced by David Schulman.

Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: Linda Cicero / Stanford News Service

For modern Earthlings, our fascination with extraterrestrial life has focussed on one place in particular:

Mars.

The planet today is a forbidding, arid place. But billions of years ago, Mars may have had a gigantic ocean. It was, like Earth, just the kind of place you’d think life could get started.

Earlier this month, in the journal Science, NASA astrobiologist Dr. Jen Eigenbrode and her team published a stunning discovery. The Curiosity rover on Mars had found rocks that contain organic molecules — the building blocks of life.

On this episode of Orbital Path, Dr. Michelle Thaller sits down with Eigenbrode to understand what this discovery really says about the possibility of life on Mars.

This episode of Orbital Path was produced by David Schulman.

Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: NASA

Lately, she’s been concerned about the future of the planet.

Specifically, Zoe has been learning about the phenomenon of planetary dehydration — and she wanted to ask Dr. Michelle Thaller what would happen if Earth lost its water.

It’s part of a new Orbital Path project called “Telescope,” where Dr. Michelle Thaller fields astronomy questions from public school students.

Michelle says dehydration isn’t anything we’ll have to worry about in our lifetimes. But in 200 million years — not all that long, in astronomical terms — our planet could resemble the desert world of Frank Herbert’s “Dune.”

Orbital Path is produced by David Schulman. The program is edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Dr. Michelle Thaller.

The music heard in this episode is “Austin 1” by Manwomanchild.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Mars image credit: NASA

Secrets of the universe? A glimpse of the whiteboard in the office of Nobel Prize-winning astrophysicist Adam Riess.

Adam Riess was only 41 when he was named a Nobel Prize winner. The Johns Hopkins distinguished professor of astronomy shared in the award for his work on something called “dark energy” — a discovery that over the past 20 years has profoundly shifted our understanding of the universe.

Riess made news again recently when he and colleagues working with the Hubble Space Telescope announced new findings about the rate at which the universe is expanding — findings which simply cannot be explained by physics as we know it.

It’s weird and profound stuff. Our story begins a century ago, with a riddle posed by a curious part of Einstein’s Theory of General Relativity — something called the “Cosmological Constant.” The fate of the universe just may hang in the balance.

This episode of Orbital Path was produced by David Schulman.

Our editor is Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: David Schulman

We’re grappling with the big, cosmic questions that preoccupy kids.

It’s part of a new project called “Telescope,” where Dr. Michelle Thaller takes on the really big questions in astronomy—from public school students.

In this episode, Michelle fields questions from Mr. Andersen’s Earth Science class at MS 442, a public school in Brooklyn.

Sarah Cole asks about creating artificial gravity on spacecraft. And Carter Nyhan wonders whether the stars guiding mariners ancient and modern, were, by the time their light reached the earth, completely kaput. Is the twinkling night sky actually a graveyard of dead stars?

Orbital Path is produced by David Schulman. The program is edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Dr. Michelle Thaller.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Image credit: NASA image of the International Space Station, where gravity does, in fact, still apply.

Gravitational wave detectors in Louisiana and Washington state had detected a disturbance from deep space.

The effect was subtle — these detectors and a sister site in Italy measure disturbances smaller than a proton. But the evidence was dramatic. And the story they told was truly cataclysmic:

A pair of neutron stars had spiraled to their deaths.

That apocalyptic collision of two super-dense stars bent the very fabric of space time — just as Einstein had predicted. It sent Gamma rays out into deep space. It created an immense cloud of gaseous gold.

And, 130 million years later, astronomers on earth witnessed the final 100 seconds of these two stars’ dance of death. It’s taught us where gold came from, and helped humans understand other intractable mysteries of the universe.

In this episode of Orbital Path, Dr. Michelle Thaller speaks with two astronomers who watched this cosmic death tango from the best seats in the house.

We’ll hear from Dr. Vicky Kalogera. She’s Director of CIERA — the Center of Interdisciplinary Exploration and Research in Astrophysics at Northwestern University. Kalogera was a lead author on a journal article on the neutron star collision co-authored by close to 4,000 scientists.

We’ll also hear from physicist Mike Landry. He’s Head of LIGO Hanford — one of the sites that, in collaboration with Italy’s VIRGO detector, measured the neutron stars’ characteristic gravitational waves.




Orbital Path is produced by David Schulman. The program is edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Dr. Michelle Thaller.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance. More at sloan.org

Image credit: CALTECH/NSF/LIGO Sonoma State University/A. Simonnet

Neutron star audio chirp credit: LIGO/University of Oregon/Ben Farr

The ozone layer had a hole in it.

A big one. And this hole was growing very quickly. If it continued to grow, the consequences would be dire.

Presented with the science, world leaders came up with an international agreement. The Montreal Protocol, as the treaty was called, may elicit shrugs today. But it staved off disaster for Earth. It was a remarkable success story, and our planet today would be a very different place if not for the Montreal Protocol and the so-called “blue sky” scientific research — research for curiosity’s sake — that led to the discovery of the rapid deterioration of the ozone layer, and its causes

In this episode, we return to a program originally broadcast in January 2017 — one that is perhaps even more relevant today.

Orbital Path is from PRX and produced by David Schulman. Justin O’Neill produced this episode. Orbital Path is edited by Andrea Mustain, with production oversight by John Barth and Genevieve Sponsler. Hosted by Dr. Michelle Thaller.

Support for Orbital Path is provided by the Alfred P. Sloan Foundation, enhancing public understanding of science, technology, and economic performance.

Like Uranus, where parts of the planet go 42 earth years without seeing the sun. Or Mars, where winters are made colder by an orbit politely described as “eccentric.” Or Saturn — where winter’s chill is deepened by the shadow of the planet’s luminous rings. 

Marshmallow, anyone?


Orbital Path is produced by David Schulman. The program is edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Dr. Michelle Thaller.

Photo credit: NASA

They worry about asteroids and comets. 

Like the one that exploded over Chelyabinsk, Russia in 2013. It was about 20 yards across. An asteroid 150 yards in diameter could take out a city. An even bigger one — as the dinosaurs reading this will attest — could change earth’s ecology, and lead to mass extinctions.

Kelly Fast, program manager for NASA’s office of planetary defense, tells Dr. Michelle Thaller about an asteroid that watchers in Hawaii recently sighted:  a mysterious, massive, cigar-shaped object. 

Millions of years into its journey, it was traveling faster than any spacecraft ever built by humans. It’s the first object ever known to visit our solar system that originated in the orbit of another star. Too fast to be trapped by our sun’s gravity, it’s now traveling a path that will take it back into deep, interstellar space.



Orbital Path is produced by David Schulman. The program is edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Dr. Michelle Thaller.



Illustration credit: ESO/M. Kornmesser

But, as the season changes and Orion returns to view, Michelle still finds plenty of wonder left for us to see — even with the naked eye — in the cold, clear air of a winter’s night.



Orbital Path is produced by David Schulman (who returns this episode to answer Michelle’s questions about his recent alleged alien abduction). The program is edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.



Photo credit: abductee# 29JE0391-RL-4S

So this week, we’re dusting off the theremin and returning to one of our favorite early episodes — “Must Be Aliens.”

Dr. Michelle Thaller talks with Phil Plait — AKA the “Bad Astronomer” — about the Kepler mission to find planets circling other stars … and why we humans are so quick to ascribe the unknowns of the cosmos to aliens.

In the two years since this episode was originally produced, however, the universe has not stood still. So Michelle has an update on the Kepler project — and a discovery that, once upon a time, had certain astronomers murmuring the “A” word.

Orbital Path is produced by David Schulman and edited by Andrea Mustain. “Must be Aliens” episode produced by Lauren Ober. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

In this episode of Orbital Path, Dr. Michelle Thaller describes her recent adventures in Bhutan — including a climb to a Buddhist monastery perched on the face of a cliff. In that rarefied air, Michelle was confronted by a link between the thinking of contemporary astrophysicists and old-school Bhutanese monks: a challenging concept of Time.


Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.


Photo credit: Michelle Thaller

Our world makes sense thanks to mathematics. Math lets us count our livestock, it lets us navigate our journeys. Mathematics has also proved an uncanny, stunningly accurate guide to what Brian Greene calls “the dark corners of reality.”



But what happens when math takes us far, far beyond what we — as humans — are equipped to perceive with our senses?  What does it mean when mathematics tells us, in no uncertain terms, that the world exists not in three, not in four — but in no fewer than eleven dimensions?



In this episode of Orbital Path, Brian Greene, director of Columbia’s Center for Theoretical Physics and a celebrated explainer of how our universe operates, sits down to talk with Dr. Michelle Thaller. Together they dig into the question of how we — as three-dimensional creatures — can come to terms with all those extra dimensions all around us. 


Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.



Photo credit: World Science Festival / Greg Kessler.



For more, visit briangreene.org

Specifically, the power of mathematics to describe the universe.

That’s because, beyond the comforting world of Newtonian physics, math gets mind-bendingly weird. So from the relative safety of their backyard hot tub, Dr. Michelle Thaller and Booth (who happen to be married) try to sort out what it really means to live not in just three dimensions, but in eleven — as mathematics now tells us we do.

Join us in the hot tub as we turn on the jets, get wet, and weird…and just a little freaked out.

Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Photo: To see Michelle and Andrew in hot tub please use dimension 5.

A few thousand years later, NASA is ready to do the job right.

The Parker Solar Probe is scheduled to fly in 2018. The spacecraft has a giant heat shield, tested to withstand 2,500-degree temperatures.

For something so basic to all of our lives — and fundamental to the science of astronomy — the sun remains surprisingly mysterious. To learn more, Michelle meets up with Nicky Viall, a NASA heliophysicist working on the mission. She describes how direct measurements of the sun’s super-hot plasma, and solar wind, may dramatically enhance our understanding of the star at the center of our lives.



Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Photo credit: NASA

NASA astronomer Andrew Booth spends his days working with lasers, developing some of the word’s most advanced telescopes. When he gets home from work, he loves to pour a glass of wine and slip into the hot tub.

And ponder some of the weirder aspects of astrophysics.

Orbital Path host Dr. Michelle Thaller (who happens to be married to Booth) rather avidly shares this enthusiasm.

For Orbital Path’s first adventure in Hot Tub Physics, the topic is: The weirdness of light. And something called interferometry. And telescopes that don’t work unless a single particle of light can be two places at exactly the same time.

Which raises the question: Are we living in a parallel universe?

Join us in the hot tub as we get wet and weird (the water’s just fine)!

Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

(You didn’t really expect a NASA photo this time, did you?)

There was a time before planets and suns. A time before oxygen. You could say there was time, even, before what we think of as light.

Back in 1989, the Big Bang theory was still in question. But that year, a NASA team led by cosmologist John Mather launched a mission to probe the earliest moments of the universe.

Mather won the Nobel Prize in Physics for his work on the Cosmic Background Explorer (COBE). This work dramatically confirmed the Big Bang theory — and, as part of it, Mather and his team took a picture of the very first light escaping into our universe.

In this episode, Dr. Thaller visits Mather to talk about these discoveries, which transformed scientific understanding of the universe. We also hear about Mather’s current project: an orbiting space telescope twice the size of the Hubble. It promises to capture the first light of galaxies and stars, and even distant planets not unlike our own.

Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Photo credit: NASA

For more, here’s a vintage 1989 video on the COBE project.

NASA is relying on hi-tech lasers — and some vintage U.S. Navy hand-me-downs — to learn about the polar regions of a remarkable, watery planet. It’s located in the Orion spur of our galaxy. NASA scientists have detected mountain ranges completely under ice. But the remaining mysteries of the ice here are profound, and what the science tells us could have dramatic impact on human life.

In this episode, Dr. Thaller visits with two key members of NASA’s IceBridge mission — Christy Hansen, Airborne Sciences Manager at the Goddard Space Flight Center, and Joe MacGregor, Deputy Project Scientist for Operation IceBridge.

Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Photo credit: NASA

Orbital Path is produced by David Schulman and edited by Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Recently, we’ve started to get the first images back from Juno, which is on a mission to Jupiter. Host Dr. Michelle Thaller walks us through the results so far and how you can participate in what Juno discovers next.

[Image of Jupiter from the Juno spacecraft.](https://www.nasa.gov/missionpages/juno/images/index.html)_

When the Cassini spacecraft blasted into space on October 15, 1997, even the most optimistic scientists would have had a hard time predicting the mission’s success. One of Cassini’s biggest legacies will be how she gave us a clearer picture of Saturn’s 62 moons, including two worlds that scientists now think could potentially host life.

Dr. Michelle Thaller speaks with the Cassini mission’s Project Scientist Linda Spilker and with Julie Webster, a longtime Cassini engineer. Cassini will crash-land into Saturn’s atmosphere this September, ending nearly 20 years of exploration of our own solar system.

Orbital Path is produced by Justin O’Neill and editor Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Image caption: The image was taken with the Cassini spacecraft wide-angle camera on Feb. 4, 2015 using a spectral filter centered at 752 nanometers, in the near-infrared portion of the spectrum. Courtesy NASA.

Nearly 100 years after Einstein predicted the existence of gravitational waves — huge undulations in the fabric of space-time itself — in 2015, detectors here on Earth finally picked up the signal of these massive disturbances.

Dr. Michelle Thaller pulls apart the power and mystery of gravitational waves, and talks with Dr. Janna Levin, theoretical astrophysicist and author of the book, Black Hole Blues and Other Songs From Outer Space.

Image caption: The LISA Pathfinder Mission paves the way for our first space-based gravitational wave detector. Having these detectors in space, instead of on Earth will make them much more sensitive and have less interference from other Earth-based noises, in our search for more clarity on gravitational waves.

Image courtesy NASA JPL / ESA.

Orbital Path is produced by Justin O’Neill and editor Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Listeners, we’ve heard you! You requested more episodes, so we present the first of our mini episodes. They’ll arrive two weeks after each monthly regular episode, and include Michelle Thaller’s insight on the latest space news. Enjoy episode one:

NASA’s NICER (Neutron star Interior Composition Explorer) mission will launch in May. Michelle explains the NICER mission’s many applications, including the possibility of using neutron stars as intergalactic global positioning systems.

Orbital Path is produced by Justin O’Neill and editor Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Image courtesy NASA: A star’s spectacular death in the constellation Taurus was observed on Earth as the supernova of 1054 A.D. Now, almost a thousand years later, a superdense neutron star left behind by the stellar death is spewing out a blizzard of extremely high-energy particles into the expanding debris field known as the Crab Nebula. This composite image uses data from three of NASA’s Great Observatories.

Space science can help track what’s happening on Earth. In this podcast episode, Orbital Path talks landslides and the satellites that monitor them for the third anniversary of the deadliest landslide in US history.

On March 22, 2014 a 650-foot hillside collapsed and covered the community of Oso, Washington. Forty-three people died. Hear from scientists working to investigate this landslide and predict future ones, as well as a woman who witnessed the landslide.

David Montgomery studied the Oso landslide’s remains as part of the ‘Geotechnical Extreme Events Reconnaissance’ (GEER) team that investigated the landslide and tried to pinpoint the causes that lead to the Oso landslide.

Dr. Dalia Kirschbaum, of NASA’s Goddard Space Flight Center, studies landslides from space using satellites to create various models. Her goal is to develop a model that can be used as the foundation for a global landslide predicting software that can help keep people living in wet, mountainous regions safe from the slides.

And Asheley Bryson is the manager at the Darrington Sno-Isles Library, which is just a few miles from the site of the landslide. She shares her memories from that day.

Orbital Path is produced by Justin O’Neill and editor Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

Image by Jonathan Godt, courtesy of U.S. Geological Survey.

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.

In this episode, 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.

Hand thinks Europa has the best chance of fostering living alien life at this moment in time. “If we’ve learned anything about life on Earth, where there’s water, you find life and there’s a whole ton of water out at Europa,” Hand says.

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.

Image credit: Courtesy NASA’s Galileo spacecraft.

Orbital Path is produced by Justin O’Neill and editor Andrea Mustain. Production oversight by John Barth and Genevieve Sponsler. Hosted by Michelle Thaller.

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.

In the episode:

Atmospheric chemist Dr. Susan Solomon shares her story of leading a team of scientists to Antarctica, scrambling to understand the problem and pretty quickly finding the root cause: a group of chemicals called chlorofluorocarbons that people were releasing into the atmosphere on the other side of the planet.

NASA chemist Dr. Anne Douglass explains ozone and and the very serious consequences of living in a world without an ozone layer. She also compares the decisive Montreal Protocol to the very different modern reaction to climate change, where American politicians openly deny the science at the root of a global crisis.

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.

In this Episode:

On November 5, 2012, astronomer Scott Sheppard and his team discovered a small, frozen space rock at the edge of what we’re able to observe in our solar system. He never anticipated that this observation would hint toward a big change in how we understand solar system: the existence of an undiscovered planet inside our solar system.

Astronomer Mike Brown, better known for “killing Pluto,” is leading the hunt for Planet Nine and he thinks that we won’t have to wait for much longer.

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.

Guests:

Jeremy Schnittman

Paul Murdin

Christopher Kochanek

Image:

Created by Jeremy Schnittman; a simulation of a black hole accretion disk, and also inspired by “Interstellar”.

The sun can seem like a friendly celestial body. It is the source of summer, crops, and basically all life on Earth. But just as the sun decided when life on Earth could begin, it will also decide when life on Earth will definitely end.

Dr. Michelle Thaller speaks with Dr. C. Alex Young, Associate Director for Science in the Heliophysics Division at NASA’s Goddard Space Flight Center. 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.

Episode Extras

C. Alex Young’s office doormat at NASA Goddard!

This 2015 video celebrates five years of solar observations from NASA’s Solar Dynamics Observatory:

Follow along with the development of Solar Probe Plus, slated for launch in 2018.

Find out about the fleet of Sun-observing spacecraft NASA uses to monitor our home star.

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.

Don’t miss the episode extra below. Michelle stands outside the clean room where the James Webb Space Telescope is being built and walks us through what we’re seeing:

Don’t miss the next Orbital Path episode, either! Subscribe here.

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.

Episode Extras

This image of asteroid Vesta is one of many images taken by NASA’s Dawn spacecraft to create an animation showing the diversity of minerals through color representation.

This view from NASA’s Dawn spacecraft shows a fresh crater among older terrain on Ceres.

Learn more about Dawn and see even more amazing photos right here.

Orbital Path is produced by Justin O’Neill and hosted by Michelle Thaller.

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 a 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 and learn where best to view the August 21, 2017 total solar eclipse.

Episode Extras

Mike Kentrianakis taking a photo of the eclipse.

Mike viewing the eclipse with a solar filter.

Joe Rao and the captain.

Full group of eclipse chasers on the flight.

Orbital Path is produced by Justin O’Neill and hosted by Michelle Thaller.

Photos courtesy of Michael Kentrianakis.

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

In this special Mother’s Day episode, Michelle talks with her mom about what it was like raising a space-obsessed daughter in Wisconsin and watching her grow into a scientist.

Big hair ’80s. Michelle’s sister, Michelle and her mom.

Michelle’s sister, Michelle, and her mom today.

—

Lauren Ober, Producer

Andrea Mustain, Editor

Genevieve Sponsler, Production and Distribution Manager

John Barth, PRX Chief Content Officer

—

This is our first episode of Orbital Path, a new monthly series from PRX. Learn more here and check out our other science series, Transistor.