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

March Equinox

Spring arrives in the northern hemisphere tonight, at the moment of the March equinox, as the Sun crosses the celestial equator. Day and night are about equal across the entire planet — hence the name “equinox,” which means “equal nights.”

The Sun is passing through Pisces, the fishes. In fact, it’s appeared in Pisces at the equinox for a couple of thousand years. Before that, it was in Aries, the ram. The shift is the result of an effect known as precession of the equinoxes.

Earth wobbles on its axis like a spinning gyroscope. As it wobbles, the Sun’s location against the background of stars moves, too. When the modern constellations were first drawn, the Sun appeared in Aries at the March equinox. So even today, the point of the equinox is sometimes called the First Point of Aries.

The Sun and equinox bring up a point about the constellations. There are actually two types of designations — one for astronomy, and the other for astrology. In astrology, the zodiac is divided into 12 roughly equal constellations. The Sun is “in” each constellation at set dates — they don’t change with precession.

In astronomy, each constellation has precisely defined borders. And the constellations are all different sizes. Pisces is fairly wide, so the Sun remains within its borders for a while. The Sun entered Pisces on March 11th, and won’t slide over into Aries — the next constellation over — for another month.

Script by Damond Benningfield

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Upcoming Topics

  • March 25-31: Mars on Earth

    Scientists are trying to understand more about Mars — and plan for human missions to the Red Planet — by studying Mars-like spots on Earth — and by making their own bits of Mars.

  • March 18-24: Going Small

    So far, the search for heavy particles that might make up dark matter have come up empty. So scientists are starting to search for tiny particles as well, and we’ll have details.

  • March 11-17: Rhythm and Blues

    A planetary science conference features haiku, limericks, and other rhythms this week, and we’ll have details. We’ll also talk about colorful stars, including bright blue Rigel, and much more.

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