Dean Regas chats with astronomer David Levy, unpacking the discovery of the famous Comet Shoemaker-Levy 9. Listen in and find out how you can start chasing comets yourself.
Additional resources referenced in this episode:
- Cosmic Collision : Comet P/Shoemaker-Levy 9, NASA
- Neil deGrasse Tyson on Comet Hyakutake at Charlie Rose (1996)
- ITV News - Hale Bopp Comet (Mar 1997)
- Stargazers: Finding Joy in the Night Sky, David Levy
Episode Transcript:
Looking Up is transcribed using a combination of AI speech recognition and human editors. It may contain errors. Please check the corresponding audio before quoting in print.
Dean Regas: It's a hot steamy summer night, July 1994. I'm sitting in my first apartment in Cincinnati, Ohio, watching the boxy TV across the room.
[Archival Audio]: In mid-July, major telescopes on earth and in space will be trained on planet Jupiter. For an encounter that could be one of the most significant astronomical events in history.
Dean Regas: I was glued to what was happening in space, possibly for the first time in my entire life. Because a comet was hitting the planet Jupiter.
[Archival Audio]: A string of over 20 ice and dust fragments from an ancient comet will plummet into Jupiter causing massive explosions.
Dean Regas: I was mesmerized by this story, and I awaited the first pictures of this explosive, astronomical event.
[Archival Audio]: Geologist Eugene Shoemaker, astronomer Carolyn Shoemaker and amateur astronomer, David Levy found the comet at the end of March 1993.
Dean Regas: I was thinking, what would this look like? What happens when a comet hits a planet?
From the studios of Cincinnati Public Radio, I'm your host, Dean Regas, and this is Looking Up the show that takes you deep into the cosmos or just to the telescope in your backyard to learn more about what makes this amazing universe of ours so great. My guest today is David Levy, amateur astronomer science writer, and discoverer of, oh, so many comets, including Shoemaker-Levy 9, which ran into Jupiter.
Now, I wouldn't say Comet Shoemaker-Levy 9 completely changed my life's path. I was still in college, I eventually graduated with a history and education degree. But back in the summer of 1994, this was more than three years before an accidental job transfer took me from doing nature education at a city park to giving planetarium shows.
That was my first astronomy gig, but maybe just maybe that fractured comet pointed me in a direction because soon after 1994, we had these other brilliant comets that followed. In 1996 we had Comet Hyakutake, which graced the skies with the skinny tail.
[Archival Audio]: Crowds have gathered on mountain tops and deserts and stadiums, and even city street corners to witness what has been called the comet of the century, Hyakutake.
Dean Regas: And then in 1997 we had Hale-Bopp, which I think a lot of people remember because it was so incredibly bright up there.
[Archival Audio]: Astronomers around the world are turning their telescopes to the northern skies to observe the biggest, brightest and most active comet to visit the solar system in our lifetime, Hale-Bopp
Dean Regas: Now in the early 2000s I was finally an astronomer. At Long last I was working at the Cincinnati Observatory, and it was there that I met astronomer and co-discoverer of Shoemaker-Levy 9, David Levy.
It was kind of funny because we were sitting around at a restaurant and back then we were all just assuming comets we're gonna light up our night sky. Every year we're just like, oh yeah, another comet another year. And David had just returned from an eclipse expedition somewhere or other, probably some exotic location, and he was preparing to do something no one had ever done before. That was observe a total solar eclipse from the continent of Antarctica.
Now, I'd never seen a total solar eclipse and told this comet guy David that I was just gonna wait until 2017, you know, when the eclipse had passed through nearby Kentucky. And David gave me the dirtiest look, and he said, ‘What are you crazy? Why would you possibly wait another decade or even another year? You gotta see one. You know, you gotta see all of them.’
Well, I didn't go to Antarctica with David, but he definitely motivated me to see the total solar eclipse in Greece in 2003. It was a cruise around the Mediterranean just for us Eclipse chasers, and David was there too. And at the moment of totality. He was giving the play by play on the PA system.
[David Levy over PA system]: Look at the shadow coming into the west.
Dean Regas: So that's David on the PA system, and he's saying over the boat, look for the shadow of the eclipse coming. So we're looking out from the distance and looking for the shadow of the moon sweeping across the waves. And then he says, all right, put your glasses back on.
[David Levy over PA system]: Glasses on. Look at the...
Dean Regas: Look up at the eclipse, which is still partial eclipse at that time. Glasses off. Look at the shadow coming in. And then finally he says, take your glasses off and stare at the sun.
[David Levy over PA system]: Glasses off. Look at the sun. We are now in totality!
Dean Regas: We're in total solar eclipse. It was incredible, indescribable. I was hooked and I had David Levy to thank for it.
David Levy: My name is David Levy, nicknamed Doveed, and I am not an astronomer, not even an amateur astronomer. I am a stargazer and I have been a stargazer since July the fourth, 1956.
Dean Regas: Well, David, thanks so much for joining me, so what happened on that memorable day?
David Levy: Well, it was the 4th of July 1956. I was in summer camp in Vermont. We were heading up back to our cabin and I looked up and I saw a very faint shooting star, and I asked the other kids if they had seen it and they said no. And my little 8-year-old David brain said, ‘Is this little shooting star just for you?’
And I put it away. I've never forgotten it. Obviously, I'm mentioning it today, and that's how it began. And, and then of course it led you to comets. And, and what is it about comets, do you think, what is it about them that inspires, you know, the average person and star gaze are alike? Well, comets are really so special to me.
It offers a way for people to interact personally with the universe. And to prove that I would like to offer to you right now my very favorite poem. It was Gerard Manley Hawkins, 1864, after he saw a Comet temple and he wrote this poem:
I am like a slip of comet,
Scarce worth discovery, in some corner seen
Bridging the slender difference of two stars,
Come out of space, or suddenly engender’d
By heady elements, for no man knows;
But when she sights the sun she grows and sizes
And spins her skirts out, while her central star
Shakes its cocooning mists; and so she comes
To fields of light; millions of travelling rays
Pierce her; she hangs upon the flame-cased sun,
And sucks the light as full as Gideons’s fleece:
But then her tether calls her; she falls off,
And as she dwindles shreds her smock of gold
Between the sistering planets, till she comes
To single Saturn, last and solitary;
And then she goes out into the cavernous dark.
So I go out: my little sweet is done:
I have drawn heat from this contagious sun:
To not ungentle death now forth I run.
Dean Regas: Ah, beautiful, beautiful. And so obviously, comets have gotten hold of you, that's for sure. Take us back to 1993 and, you co discover a comet with Carolyn and Eugene Shoemaker, these great friends of yours also. And this was your ninth comet that you discovered together. Tell us what happened, especially when you heard the news of what the comet was going to do.
David Levy: Well, actually we knew it was special immediately because. When Carolyn found the comet on a film I loaded into the telescope, she said, ‘I think I found a squashed comet!’ And so it was very unusual right from the get go. But what really happened, what really was the highlight of my professional light was on my birthday, May 22nd, 1993. I had heard from the director of the Minor Planet Center that, uh, something major was going to happen. He said, ‘I'm not gonna tell you what it is, but be ready for it.’
And he sent out two announcements. One was the name was changed from Comet Shoemaker-Levy to Comet Shoemaker-Levy 9, meaning it was the ninth comment we had found that is technically an orbit around the sun and comes back periodically. And there was something in the where the positions would be that wasn't in any of the others that he had ever published.
It was called the Delta J, the distance between the Comet and Jupiter, because the Comet was actually orbiting Jupiter rather than the sun directly. And I’m looking at this Delta J, and noticing as time goes on, that the Delta J is getting smaller and smaller and smaller. And finally I said, Carolyn, the last number he has for the Delta J is less than the Radius of Jupiter. And Carolyn looked up and said, ‘David, we're gonna lose our comet. There’s gonna be a collision isn’t there?’
And the second circular that he came out with said, in case you didn't notice, there is going to be almost certainly a collision starting on July 16th, 1994, and that moment was the crowning moment of my professional career.
Dean Regas: Yeah, but how did it feel? It had to have a little mixed feelings, uh, you know, uh, have the Comet, Shoemaker-Levy 9 and it's doomed. How did that feel? Or was it just like, oh yeah, 9 I found the best Comet ever.
David Levy: Well, we got very emotional. Carolyn said, ‘We're gonna lose our comet.’ Her husband Gene started yelling. He said, ‘Don't move. I gotta see this for myself.’ And he rushes out and he looks at the ephemeris and he's almost in tears. He said, ‘In my lifetime, we are going to see a comet, strike a planet.’ And I mean, the guy was almost in tears. And the rest of the afternoon, believe it or not, we were pretty quiet. We knew what it would do to the comet and what it would do to us, and it was really very, very special.
Dean Regas: Oh, I love it. And, and you're also the author of several books, including Making Friends with the Stars. And you know, I always tend to gravitate towards people who generally enjoy what they do. And you can always tell that you love what you're doing. What's, what's your secret?
David Levy: It's a very simple secret. I go out every night, open the observatory. I looked up at the stars, and no matter how bad my mood might be that day, it always offers me a sense of peace. My latest book, by the way, is called Stargazers: Finding Joy in the Night Sky, and it is a compilation of articles I've written over the last 10, 20 years.
Dean Regas: Well, excellent. You've been an inspiration to me from seeing an eclipse with you out in Greece to, uh, just chatting. I always enjoy talking to you, David.
David Levy: Thanks so much. Thank you so, so much. I'm really glad to have been here.
Dean Regas: So why have comets been so disappointing lately? I mean, by lately, I mean like the last 25 years because the last really good comet and I mean really good comet was Comet Hale Bopp back in 1997 and it's really been a comet drought.
This has been a very, very long time. I'm still trying to like live in the past, I guess I'm still thinking about, uh, comet Hale Bopp and Hyakutake back in the 90s and thinking, what is going on? Why haven't we had another really good one since then?
And there's a big problem with Comet predictions because comets are fickle beasts. They do what they want. We can hardly tell what they're gonna do and how bright they're gonna get. And so, some that look really, really promising, often fizzle out. And that's pretty much what's been happening the last 25 years. So, what can we do about this? We need a good comet. We're due. Let's get a comet up there somehow.
Let's do it. Looking up with Dean Regas is a production of Cincinnati Public Radio. Kevin Reynolds and I created the podcast in 2017. Ella Rowen produces and edits our show and is so young that she's never seen a truly great comet. Yeah, that's right. I'm gonna tell you again about what it was like back in my day seeing Hale Bopp!
Jenell Walton is our Vice President of Content, and Ronny Salerno is our digital platforms manager. Our theme song is Possible Light by Ziv Moran. Our social media coordinator is Hannah McFarland, and our cover art is by Nicole Tiffany. I'm Dean Regas. Keep looking up.
