Radio’s Guide to the Universe

StarDate host Billy Henry

StarDate debuted in 1978, making it the longest-running national radio science feature in the country. It airs on more than 300 radio stations. It has been hosted by Billy Henry since July 2019.

StarDate tells listeners what to look for in the night sky, and explains the science, history, and skylore behind these objects. It also keeps listeners up to date on the latest research findings and space missions. And it offers tidbits on astronomy in the arts and popular culture, providing ways for people with diverse interests to keep up with the universe.

StarDate is a production of The University of Texas McDonald Observatory, which also produces the bi-monthly StarDate magazine.

The Voice of StarDate

Billy Henry, a voice talent, musician, composer, and college lecturer in Austin is the third narrator of the StarDate radio program. Read more »

The Music of StarDate

The StarDate background music was written by Bill Harwell and Patterson Barrett specifically for StarDate.

More Than 40 Years and Counting!

StarDate is radio’s longest-running nationally aired science program. It began in 1977 as a daily telephone message service by McDonald Observatory. It was picked up by Austin radio station KLBJ-FM, and aired as “Have You Seen the Stars Tonight?” beginning in June 1977. With a grant from the National Science Foundation, the program became “Star Date,” and began airing nationally, seven days per week, on October 1, 1978. It quickly reached more than 1,000 stations across the country. Read more »

Today’s Episode

Moon and Saturn

Saturn is almost 10 times farther from the Sun than Earth is. At that distance, the Sun looks only about one percent as bright as it does from Earth, soSaturn is cold and dark. But it’s not quite as cold as you might expect. Saturn actually puts out more than twice as much energy as it receives – heat radiating from deep inside the planet.Saturn is made mostly of hydrogen and helium – the lightest and simplest chemical elements. But its core contains a lot of rock, metal, and other heavy materials – more than 15 times the total mass of Earth. Gravity squeezes the core tightly, causing it to shrink. That produces heat, which rises to the surface and shines out into space.But that doesn’t explain all of Saturn’s heat. The rest may come from an odd type of rainfall. Droplets of liquid helium may fall toward the core. As they fall, they produce friction, which produces heat.Saturn’s internal heat drives much of the weather in its atmosphere, including storms that can be as big as continents – swirling clouds on a cold, dark planet.Despite the lack of sunlight, Saturn looks bright in our sky because it’s huge – about nine times the diameter of Earth. It’s easy to see how bright the next couple of early mornings because it’s close to the Moon. Tomorrow, it’s to the lower left of the Moon at dawn. It’ll be a little farther to the right of the Moon on Wednesday.Script by Damond Benningfield
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Upcoming Topics

  • July 13-19: The Milky Way

    Our home galaxy is at its best on summer nights, and we’ll tell you where to look for it. We’ll also talk about the galaxy’s “zone of avoidance,” its dark heart, and more. Please join us for tales of our galactic home and more.

  • July 6-12: Pairing Up

    The Moon pairs off with the planet Saturn early this week, while the planet Venus pairs up with the heart of the lion all week long. We’ll have details about both encounters.

  • June 29-July 5: New Explorations

    A Japanese spacecraft is headed toward an encounter with an asteroid this month, while an American lander may be ready to head for the Moon. Please join us for these missions and more, right here.

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