

KGNU - How On Earth
KGNU - How On Earth
The KGNU Science Show
Episodes
Mentioned books

Dec 9, 2025 • 27min
World Domination…by Slime Molds?
On today’s show, Beth speaks with award-winning science writer Jennifer Frazer about her upcoming book: The Slime Mold’s Guide to World Domination: A Natural Mystery. The book is a funny natural history of slime molds that’s also a mystery that asks: how can a giant crawling cell possibly be intelligent?” Jennifer has degrees in biology and plant pathology from Cornell University and in science writing from MIT, AND has blogged about the natural history of neglected organisms for nine years for Scientific American. Get ready for an eye-opening visit to the peculiar world of slime molds, not the creepy crawly things you may expect. Also, delightful dialog from the new crop of interning journalists, our Earhtlings!
Executive Producer: Beth Bennett
Show Producer: Beth Bennett and Shelley Schlender
Additional Contributions: Benita Lee and Mac Hebebrand
Listen to the Show:

Dec 2, 2025 • 27min
Critical Earth Minerals Hiding in Plain Sight – Elizabeth Holley
Elizabeth Holley cc Colorado School of Mines
Critical Earth Minerals Hiding in Plain Site – Colorado School of Mines professor Elizabeth Holley shares how the US could break its dependency on critical earth mineral imports, and lead the world in environmentally safe ways to do it.
Show Producer/Host/Engineer: Shelley Schlender
Executive Producer: Beth Bennett

Nov 25, 2025 • 27min
Better Steam//CU-Boulder at World Climate Conference
Todd Bandhauer with heat pump – cc CSU
Great Steam . . . from a Heat Pump (starts 1:00) Time Magazine named CSU Engineer Todd Bandhauer one of 2025’s top climate innovators. His heat pump makes steam better than fossil fuel steam boilers. Interview thanks to Rocky Mountain Community Radio and Aspen Public Radio.
Max Boykoff at COP30 cc CU-Boulder
CU-Boulder at COP30 Climate Conference (Starts 7:05) CU Boulder’s Max Boykoff attended the world climate conference –the first in 30 years without an official US delegation . He describes China filling the vacuum left by the US , and also oil and gas lobbyists attending “Blue Zone” talks where indigenous groups – who often are suffering the worst effects of climate change, being banned. For the CU-Boulder report Go here.
Show Producer/Host/Engineer: Shelley Schlender
Executive Producer: Beth Bennett

Nov 18, 2025 • 26min
Megadroughts Could Cause World Wide Dustbowls — CSU Melinda Smith Explains
Dust Storm in Texas in the 1930s
Dustbowl Days Today (starts 5:00) Colorado State University grasslands scientist Melinda Smith explains the study she conducted with the grassroots help of nearly 200 scientists around the world. Their research indicates grasslands are vulnerable to Megadroughts, which climate change is making more common. Just 4 years of drought in a row may trigger Dust Bowls on the scale of the Midwestern dustbowls of the 1930s. Smith explains why and what can be done to save regions around the world from dustbowls.
Hosts: Abby O’Brien, Lorraine Healy, Mac HebebrandShow Producer/Engineer: Shelley SchlenderExecutive Producer: Beth Bennett

Nov 11, 2025 • 26min
Winter is Coming: Why Leaves Fall
The physiology of deciduous trees (start time: 11:09) For many people living in places with four distinct seasons, such as here in Colorado, a favorite pastime at this midpoint in autumn is watching the faded leaves fall from their branches, and listening to the crackling sound while raking up the dried leaves. In this week’s How On Earth show, we explore questions like, Why do the leaves of aspen, ash and other deciduous trees “change” color in the fall? (Spoiler alert: They actually reveal their true colors.) Why do they shed their leaves every fall? And what happens to the naked trees in the winter? Host Susan Moran interviews Dr. Stephanie Mayer, a senior instructor emerita in the Department of Ecology and Evolutionary Biology at the University of Colorado Boulder.
-Resources for winter watering:
Colorado State University Extension
Denver Botanic Garden
-Resources for citizen science opportunities:
The National Phenology Network
Host/ Show Producer: Susan Moran
Cohost/Engineer: Joel Parker
Executive Producer: Beth Bennett
Headline Contributors: Lorraine Healy, Max Hebebrand, Shelley Schlender
Listen to the show here:

Nov 4, 2025 • 28min
Peak Performance: Revisiting a Classic
Five years ago, Beth spoke with Dr Marc Bubbs about his best-selling hardcover book, PEAK: THE NEW SCIENCE OF ATHLETIC PERFORMANCE. Since then, Bubbs has been on the leading edge of new developments in the physiology and psychology of athletic performance. Bubbs helps athletes and other clients in Canada and England cope with metabolic diseases, Bubbs is also the performance nutritionist for the Canadian men’s national basketball team, In addition, he consults with teams in the NBA, NFL, NHL, and MLB. On this week’s show, Beth talks to Marc about his revised edition of the book, just published, and some of the new developments and strategies he describes.
Also on this week’s show, meet our new interns from CU: Owen Latham and Mac Hebrebrand!
Executive Producer: Susan Moran
Show Producers: Beth Bennett and Shelley Schlender
Additional Contributions: Owen Latham and Mac Hebrebrand
Listen to the show:

Oct 28, 2025 • 27min
Into The Unknown (Part 2)
Into The Unknown (starts at 9:05) What do we know about the universe, and how do we know we know it? Conversely, what do we know we don’t know, what don’t we know that we don’t know, and why not?
To help us unravel these age-old philosophical questions in the context of current science, our guest is Dr. Kelsey Johnson, who received her PhD in astrophysics from the University of Colorado. Dr. Johnson is a Professor in the Department of Astronomy at the University of Virginia, and the former president of the American Astronomical Society. She is the founder of the Dark Skies, Bright Kids program, and wrote the children’s book Constellations for Kids. Her most recent book is Into The Unknown: The Quest to Understand the Mysteries of the Cosmos. In this episode, Dr. Johnson takes us into that unknown, and talks about what we know, what we might know, and what we might never know.
Part 1 of this interview is available here.
We begin this show with some pre-Halloween spooky science news.
Host: Joel Parker
Show Producer/Engineer: Joel Parker
Executive Producer: Susan Moran
Additional contributions:Benita Lee, Jack Armstrong, Shelley Schlender
Listen to the show:

Oct 21, 2025 • 27min
Into The Unknown (Part 1)
Into The Unknown (starts at 7:57) What do we know about the universe, and how do we know we know it? Conversely, what do we know we don’t know, what don’t we know that we don’t know, and why not?
To help us unravel these age-old philosophical questions in the context of current science, our guest is Dr. Kelsey Johnson, who received her PhD in astrophysics from the University of Colorado. Dr. Johnson is a Professor in the Department of Astronomy at the University of Virginia, and the former president of the American Astronomical Society. She is the founder of the Dark Skies, Bright Kids program, and wrote the children’s book Constellations for Kids. Her most recent book is Into The Unknown: The Quest to Understand the Mysteries of the Cosmos. In this episode, Dr. Johnson takes us into that unknown, and talks about what we know, what we might know, and what we might never know.
Part 2 of this interview is available here.
Host: Joel Parker
Show Producer/Engineer: Joel Parker
Executive Producer: Susan Moran
Additional contributions: Shelley Schlender, Mac Hebebrand, Lorraine Healy
Listen to the show:

Oct 14, 2025 • 27min
Autumn Insects and their Songs
cicadaCredit: Tim McNary
Science & Songs of Katydids, Cicadas, etc. (start time: 3:08) It’s the time of year to savor listening each night to the pulsating and clicking sounds of katydids, cicadas, crickets and other straight-winged insects, all crying out for a mate. Soon, with the first big frost, the songs, along with the arthropods themselves, will disappear. In this week’s show, a longtime arthropod expert, Tim McNary, talks with host Susan Moran about things like, who are these small yet very vocal insects? What’s their life cycle like? What body parts make those noises? What role do these vocal insects play in the broader ecosystem? McNary is a curator at the Gillette Museum of Arthropod Diversity at Colorado State University in Fort Collins. Previously, he worked at the U.S. Department of Agriculture in the field of grasshopper and locust management.
Hosts: Susan Moran, Joel Parker
Show & Executive Producer: Susan Moran
Engineer: Joel Parker
Listen to the show here:

Oct 7, 2025 • 28min
From Habitat Loss to Repairing Connectivity
Courtesy: Patagonia Works
Helping Wild Animals Roam (start time: 3:29) Wild animals, whether buffalos or bats, need space to move around–not just to survive, but to forage, reproduce, migrate, and generally thrive as a species. But it’s getting increasingly difficult for so many species to do this, thanks to humans breaking up their habitats to build roads, fences, housing developments, croplands, etc. Of course, climate change, pesticides, and other stressors compound the problem. In this week’s (fall fund drive) show, host Susan Moran interviews Hillary Rosner, a local environmental journalist and University of Colorado Boulder assistant teaching professor of journalism. Her debut book, called Roam: Wild Animals and the Race to Repair Our Fractured World (Patagonia Works), will be released next week. In her reporting, Hillary digs into some of the threats to wildlife here in the U.S. and elsewhere, as well as bold efforts by individual humans and communities to repair and connect landscapes enough to let many animal populations thrive. And in many cases, helping wildlife move also helps human communities become economically and socially stronger.
Hosts: Susan Moran, Joel Parker
Show & Executive Producer: Susan Moran
Engineer: Joel Parker
Listen to the show here:


