If taking a trip through the galaxy sounds like a great way to get away from it all right now, you’re probably not alone. And while you can’t just hop on a rocket, you certainly can stay tuned to what’s happening in the galaxy through groups like the SETI Institute. Originally a two-person project intended to test the probabilities of alien civilizations, SETI has grown to encompass numerous scientists all focused on searching for and understanding life beyond Earth. Part of SETI’s mission includes education and sharing popular science with the public—something SETI’s Dr. Simon Steel, Senior Director of Education and STEM Programs, knows well.
If you haven’t caught Dr. Steel’s YouTube tour of the Milky Way galaxy, you should make time for the hour-long ride—it features solid commentary and fantastic photo images. We chatted with Dr. Steel about his love of astronomy, what SETI’s up to right now, and more.
RECURSOR: How did you become interested in science, especially astronomy?
SIMON STEEL: I grew up in a time when space exploration was everywhere—the Apollo Moon landings, Star Trek and Doctor Who on TV. I remember craving a poster of the Solar System on my elementary classroom wall (at the end of the school year, unclaimed, my teacher gave it to the space geek and it went up in my bedroom!)
I also remember very clearly when my father took me to see 2001: A Space Odyssey at the cinema. I was eight! Maybe he hadn’t read the reviews, or maybe he had a plan…
What led you to become a part of SETI?
Not sure if I can credit this to Carl Sagan or Doctor Who, but I’ve always had a fascination with aliens and alien civilizations. I probably shouldn’t admit it, but I blew a school prize gift certificate on a book called UFOs from Inside the Earth. Even at my young age I could tell it was flawed, to put it mildly.
I went into astronomy, where galaxies and quasars captured my imagination, but a job opening at the SETI Institute was irresistible.
Your recent “tour of the Milky Way” YouTube event was so cool. What was the inspiration for doing it?
The concept of distance, size and scale is one of the most difficult ideas in astronomy to wrap your mind around. Most people can mentally navigate the solar system, even if its scale is difficult to fathom, but a galactic perspective is rarely taught. I wanted to give people a sense of the truly amazing scale of a galaxy, and our place and part in it. It may make you feel small, but we are all a part of something amazingly huge!
The photos shared during your YouTube event were fantastic. Where they were sourced from?
I tried as much as possible to use actual images rather than artist renderings, and most of the images are sourced from NASA. I especially love the image of Jupiter and its moon Io, which were taken by the New Horizons spacecraft during a gravity assist on its way to Pluto. It seemed fitting that, like us, New Horizons was just a tourist passing by the Jovian system and grabbing a snapshot!
To maintain the fantasy of a voyage, I tried not to say “and this image, taken by the Hubble Space Telescope…” — which meant that the images did not get the real time credit they were due. I also wanted to give a flavor of the diversity of objects that make up our galaxy, and tried to introduce a story in time as well as in space.
For example, we passed by a star forming region (the Trifid nebula), followed by a star cluster (Westerlund 1) and then the end point of stellar evolution, a black hole (Cygnus X-1). Actual astronomical images are not always available, so giving the impression of visiting the celestial objects needs a combination of art and science.
The lovely dance of Cygnus X-1 and its companion star is an animation created by NASA’s Chandra X-Ray telescope team. Through an actual telescope, this whole system is a point source in the sky, smaller than one pixel.
The animated swarm of stars around the center of SGR A*, the supermassive black hole at the center of the galaxy, was produced by Dr. Andrea Ghez using observational data from the 10m Keck telescopes in Hawaii. Although actual image data is available, the animation in time reveals beautifully the existence of the invisible black hole.
Exoplanet images, especially of their surfaces, are still highly speculative, so our final stop at Proxima Cen b owes much to the creativity of the artist, even if guided by the science!
Are there any surprising facts about our galaxy that the average person may not be aware of?
I think the sheer scale of the Milky Way is something that blows you away. Numbers like 300 billion stars, a million black holes—small ones, with one big one at the center!. The fact that it takes 220 million years to make one rotation, so one galactic year is way longer than the era of the dinosaurs.
And with so many stars, there are estimated to be 22 billion stars that are just like our Sun (Type G for those who are interested). That’s three Suns (roughly) for every human on Earth, and it’s almost certain that every one of these stars has planets. The Milky Way is a star factory, and by extension a maker of planets, and a maker of life.
How unique (or not unique) is our galaxy in terms of what we know about the rest of the universe and other galaxies?
Our galaxy is not unique. Spiral galaxies make up a large proportion of galaxies in our universe—the other types being elliptical galaxies, which are big balls of old stars, and irregular galaxies, which are a mess of stars usually due to a collision with another galaxy.
Spirals are beautiful, sweeping cities of stars whose structure makes them perfect star factories (any by extension, planet factories). In our cosmic neighborhood, there are several magnificent spirals—the Andromeda galaxy and the Whirlpool galaxy to name but two. The Milky Way would be a popular target for an Andromedan astronomer! I’d describe the Milky Way as an impressive, but not uncommon spiral.
It seems like there’s a lot of discovery happening right now around black holes. What’s driving that research?
Not only are black holes the weirdest objects in the universe, they are also the most extreme laboratories for testing known science to its limit. As the ultimate expression of gravity, astronomers test Einstein’s theory of gravity—general relativity—which explains nothing less than the origin, evolution and fate of the universe. The harder you push a theory, the more confidence you have in its predictions. A couple of big experiments are LIGO (Laser Interferometer Gravitational-Wave Observatory) which detects gravitational waves caused by colliding black holes, and the Event Horizon Telescope which recently imaged the accretion disc and event horizon of a supermassive black hole.
Are there other areas of astronomy right now that are particularly “booming” (so to speak) in terms of research and discovery?
Exoplanet research is the hot topic in astronomy right now. With almost 5,000 planets discovered orbiting other stars, there is estimated to be as many as 300 million potentially habitable worlds in our galaxy, and several likely to be within 30 light years or so of our solar system! With space telescopes such as James Webb being able to examine the atmospheres of these nearest planets, the search for life in the universe is entering its most exciting phase. SETI astronomers now have actual planetary targets to point their radio dishes at!
These days, there is talk of exploring Venus for life, settling on Mars, and going back to the Moon. Do you think one of these choices makes more sense than the other two? What would you like NASA, SpaceX, etc. to be focusing on, if you could influence that decision?
Space exploration is important on many levels. Scientifically of course, but it also drives innovation in engineering, medicine and computing. It is also unmatched as an inspiration for our future in these troubled times. Mars should be the goal, but because it’s so much easier to launch Martian missions from the Moon (lower surface gravity means smaller rockets) that the Moon has to be the initial focus, certainly for human exploration.
Settlements on Mars will happen too, but Mars is not Earth 2.0. The more we learn about Mars, the more we realize how incredibly special our home planet is. And if that’s the only thing we learn from a mission to Mars, then it has been a success!
What’s your favorite sci-fi book, movie or series? And what is it that you love most about it?
This is the toughest question of all! I’m going to be greedy and pick one from each category.
For a movie, John Carpenter’s Dark Star (1974). As well as the fabulous dark humor, it has such an original take on exoplanets, artificial intelligence and the diversity of alien life, and one of the scariest human/alien fight sequences ever filmed.
For a book, I am going to pick Arthur C. Clarke’s Rendezvous with Rama. It was the first “adult” sci fi novel I read as a teenager, and its relevance to modern ideas of searching for alien artifacts, rather than aliens themselves, gives it a fresh relevance. It also begins with an asteroid impact, and planetary defense is a research area of the SETI Institute. Anyone who’s read the novel will have thought the appearance of ʻOumuamua the fulfillment of a prophecy!
For a TV show, naming Star Trek (the original series), or Doctor Who is too easy. I also love the Gerry Anderson classic UFO (way ahead of its time) but I’ll go for The Expanse. I love the representation of the near(ish) future colonization of the Solar System, the adherence to physical concepts such as travel time, gravity and the hostility of environments. The introduction of an alien invasive species was in a way less interesting than the interaction of human cultures that have made alien worlds their own.
How can fellow science lovers support SETI’s work?
The SETI Institute is now more than its name suggests, and is researching the prevalence of life in the universe in all its forms, from microbes on Mars to advanced alien technologies. Most of our funding comes from NASA, but NASA does not currently fund SETI research itself. Likewise, some of our education projects are government funded, but our outreach projects, such as our Chabot/SETI Institute talks for families, rely on personal donations and sponsorship. We have great ideas, but great ideas are not free to implement!
If anyone is interested in how they can get involved, go to seti.org and sign up for our newsletter!
Simon Steel is the Senior Director of Education and STEM Programs at the SETI Institute. As a PhD astronomer and qualified high school teacher, Simon has spent over 25 years in education and public outreach, at Harvard University, the Harvard-Smithsonian Center for Astrophysics and at University College London. His experience spans formal and informal education, teacher training, exhibit design, multimedia product development, and working with special needs audiences.
For more insights into SETI’s work, check out our previous interviews with Dr. Seth Shostak of the Big Picture Science podcast…