Profile of exoplanet professor John Johnson

An exoplanet hunter joins the faculty

John Asher Johnson

John Asher Johnson, his wife, Erin Johnson, and their young sons Owen and Marcus meandered by car from Caltech to Cambridgeport last summer—a mere flick of an eye for the new professor of astronomy, who studies exoplanets, light years away. (Some 800 exoplanets are known, as many are being confirmed, and there are thought to be billions to trillions.) An enthusiastic teacher, Johnson outlines his field using the “Exoplanets Explained” video, in the PhD TV series on YouTube: the voices are his and his graduate students’, happily distinguishing Doppler-effect, radial-velocity planet detection from direct imaging, star transits, gravitational microlensing, and other techniques. All are in use at Harvard’s exoplanet research group, which he calls “unique in astronomy.” At Caltech, he was the team; here, colleagues include professors David Charbonneau (in whose office Johnson is camping out during a sabbatical year) and Dimitar Sasselov, lecturer David Latham, and others. Because Harvard teaching opportunities are innovative and diverse, he says, in Cambridge, “I can be a university professor in the fullest sense,” building on the nonhierarchical ethos he established at his “ExoLab” in Pasedena. When he is not playing basketball, bicycling, building Legos with the boys, or preparing to teach the introductory stellar and planetary astronomy course this spring, Johnson thinks about deploying future observational instruments on Earth and in orbit. He aims for “unambiguous detection of life signatures outside our solar system within our lifetimes.” Unlike other astronomical objects, he has written, planets “inspire a subtle emotional curiosity…because they alone can be thought of as places, not things.”

You might also like

This Astronomer is Sounding a Warning on 'Space Junk'

As debris accumulates in low Earth orbit, the danger of destructive collisions continues to rise.

Isaac Kohlberg to Step Down as Head of Harvard Technology Development

Partnerships and licensing office could become more critical as funding cuts loom

Can an Orange a Day Stave off Depression?

A research study digs into the gut microbiome.

Most popular

How MAGA Went Mainstream at Harvard

Trump, TikTok, and the pandemic are reshaping Gen Z politics. 

Two Years of Doxxing at Harvard

What happens when students are publicly named and shamed for their views?

Why Harvard Needs International Students

An ed school professor on why global challenges demand global experiences

Explore More From Current Issue

Karla Cornejo Villavicencio smiling beside the pink cover of her novel "Catalina" featuring a jeweled star and eye.

Being Undocumented in America

Karla Cornejo Villavicencio’s writing aims to challenge assumptions. 

Two women in traditional kimonos, one lighting a cigarette, in a scene from Apart from You.

Harvard Film Archive Spotlights Japanese Director Mikio Naruse

A retrospective of the filmmaker’s works, from Floating Clouds to Flowing

Julie Riew, wearing a white dress, playing guitar and singing into a microphone on stage.

Bringing Korean Stories to Life

Composer Julia Riew writes the musicals she needed to see.