Lauren Weiss, who joined the faculty at the University of Notre Dame in 2021, earned her doctorate degree in physics at the University of California, Berkeley, and has been scouring the skies to discover planets that orbit stars other than our Sun. These planets are called exoplanets.

What does your research entail?

Most of my research so far has included a broad variety of exoplanets; planets that are small and rocky, as well as planets that are large and gaseous. And a new phase of my research that I'm embarking on is specifically searching for exoplanets around the nearest stars. The nearest stars are still 30 light years away, so if there were anyone there to listen and we sent a signal, like, smiley face emoji 🙂 , we could expect to wait 60 years before getting a return message of another smiley face emoji. 🙂

Did you always want to find exoplanets?

No, actually, at the end of my undergrad, really, the biggest thing I wanted was to be making discoveries about the nature of the universe, and I wanted to be using telescopes and collecting real data about the universe. It just so happened that around the time I graduated from undergrad, a wonderful, small space mission called the NASA Kepler mission launched, and my career launched with it. (Kepler has since been decommissioned, but plenty of data remains.)

What are the tools you’re using now?

One of the tools I use was ongoing during the Kepler mission, and has really great longevity. It’s the Doppler method, where we measure the forward and backward motion of a star, and from that we can infer the masses of orbits of multiple planets around the star. The trick is we have to make many measurements over many years. A new advance that one of my colleagues designed and built is a beautiful spectrograph called the Keck Planet Finder at the W.M. Keck Observatory, for which Notre Dame is a partner. We also hope to use the James Webb telescope to study the atmospheres of both giant planets and small planets, which can tell us a little bit about where the planets formed.

Thinking about the topic of “origins,” what are some primary questions you want to answer?

I want to answer the question: Where are the nearest planets around other stars that might be suitable for life? But another related question that I've been working on actually even longer is, in general, how do planets like the Earth form? What is the physical and chemical recipe for making planets that are like Earth? In terms of the formation of small planets, there are a whole bunch of theories about how the presence of Jupiter either helped small planets grow, or possibly hindered their growth. One of the newer questions we have is, does a planet like Jupiter actually help make planets like Earth habitable?

Why should non-scientists be engaged with the work of astronomers like you?

I think part of what makes human life valuable, dignified, and worth living is that we inherently are curious about the universe that we inhabit and what our place is within that universe. The question of how we got to be here is a major part of that curiosity. I've never encountered a person who isn't curious about this question. And I think as humanity, we owe it to ourselves to make progress in answering it. I think there's always going to be more to discover, and we’re never going to have a full answer.

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Interview by Deanna Csomo Ferrell.