Standing on the Edge of Discovery with Dr. Melodie Kao

What’s it like to stand at the edge of human knowledge, where we don’t know what leap forward in understanding the next technological innovation will herald? To find out, Dr. Charles Liu and co-host Allen Liu welcome Dr. Melodie Kao, resident radio astronomer at the Lowell Observatory in Flagstaff, AZ, where Clyde Tombaugh discovered Pluto back in 1930. (And if you’re scratching your heads saying, “What’s a radio astronomer doing at an optical observatory?” you’re not alone. Short answer: Melodie convinced them they wanted one, and that it should be her!”)

As always, though, we start off with the day’s joyfully cool cosmic thing, the amazing discovery by the NEID Spectrograph at the WIYN telescope at Kitt Peak Observatory of a planet 9 times the mass of Earth orbiting a sun-like star 49 light years away with an orbital period of just 31 days. Melodie explains the precision of the measurement required to discover a planet at that distance, and shares one of her own recent discoveries using a technique called very-long-baseline interferometry (VLBI). In a groundbreaking effort she strung together 39 radio dishes across the northern hemisphere of Earth in a multi-observatory effort to create an Earth-sized telescope (similar to the technique that was used to create the first image of a black hole) and pointed it at a brown dwarf and measured its magnetic fields and radiation belts (like our Van Allen belts). For comparison, the effort was like measuring a pea perched on the Golden Gate Bridge in San Francisco while standing on the Statue of Liberty in NYC.

The trio discusses the importance of the discovery of the Van Allen belts, and how that allowed us to plot trajectories that avoided the worst of that radiation for Apollo astronauts on their journeys to the Moon.

For our first audience question, Ari from North Greene High School in Tennessee asks, “What is the percentage of possible exoplanets that are similar to the earth’s atmosphere, placed in their solar system (within a similar area of their respective Goldilocks zone), gravity, etc.? And how long would it take to hypothetically get to them?”

That turns out to be a very complicated question, and Melodie knows someone who has devoted her entire career to answering it. It’s one of the questions that drove the creation of the James Webb Space Telescope and is the basis of the Drake Equation. The bottom line, though, is that we don’t know yet, and until we find a rocky planet with an Earthlike atmosphere orbiting a sun-like star outside of our solar system, it will remain unanswerable.

Next, Charles asks Melodie how she became an astronomer, especially since she’d always planned on being an architect. She even went to MIT to become one, but she missed studying physics, which she realized she truly loved. MIT had just finished constructing their Center for Theoretical Physics, and Melodie shares the story of how she convinced MIT to bend the rules and let switch her major to Physics while continuing to study architecture. When she attended a lecture by a grad student about galaxy clusters, and learned how you could back out the formation history of a cluster of galaxies by looking at the gradients of colors generated by starlight, she realized astronomy was a way to unlock the secrets of the universe.

Our next question comes from Alex at North Greene: What are the conditions necessary for life in the universe? It’s a question without an easy answer, but the conversation it spawns is worth your time to listen to. It leads Melodie to talk about her love of exploring the natural world and how she co-created a Wilderness Astronomy class. She’s also a guide for off-trail, high route backpacking trips where you don’t know what’s coming next and you need to rely on your instincts, curiosity and bravery as you explore the world, and the universe, around you.

If you’d like to know more about what Melodie is up to, she’s not on social