Aug 12, 2015 · 4 minutes

MIT Planetary Scientist Sara Seager gave a talk Monday night at the SFJazz Center to members and guests of The Long Now Foundation.

Also included was the sly folksiness of Stewart Brand occupying the interviewer’s chair, asking questions of his own and those gathered from the crowd, including two from founding Wired editor Kevin Kelly, sitting in the front row.

The talk was part of the “Seminars About Long-term Thinking,” or SALT, series, the eclectic sponsors of which range from Chevron, to William Randolph Hearst III, to Brian Eno and two entities –  the Libra Foundation and the Scorpio Rising Fund – with astrologic names.  

There were roughly two moments of spontaneous, unbidden applause. Once, when Brand’s questioning about Seager’s teaching experiences occasioned a discussion of the epidemic entitlement of today’s youth, and its parental origins. That applause was scattered and the silence of the non-clappers loud. The other clapburst came when Seager said that she really liked programming in Python – that one just got giggles from the non-participants.   

Seager seemed inexplicably anxious during her presentation, far more so than in this TED Talk which follows the same slideshow. The crowd was supportive and polite, and seemed to try soothing her with audible-but-calm exhalations of breath and respect-stifled clearings of throat.

But Seager is a scientist who’d spent nearly twenty years studying and theorizing about and seeking the atmospheres of distant worlds, a confirmed geek and computer enthusiast. The well-seasoned audience could bear rough edges, provided access to the knowledge and passion and narrative behind the script.

What the audience palpably didn’t like were Seager’s frequent declarative statements about the limits of human knowing and technologic capacity when peering into the vast. To the veteran Silicon Valley ear this sort of talk smacks of senseless pessimism.

An especially violent burst of chair-shifting erupted when Seager said she didn’t understand Brand’s reading of a question from Kevin Kelly about the impact of Moore’s Law on space telescopes. Upon a rephrasing, she said that in her very relevent experience, the size of state-of-the-art telescopes were ever increasing, and so were the prices.

The acoustics in the newborn, $64 million mausoleum of jazz are so precise that you could hear the dismay. It’s really a great room.

Instead of exponential visions of immanent transcendence, Seager was selling a still-expensive but more modest promise: The starshade.

The skinny: so far, exoplanets are only discernible through the tracking of “transits” – when planets crossing the face of a star cause minute, machine-perceptible dips in the amount of light hitting a telescope’s lense. From this can be extrapolated, with some degree of approximation, the size of the world and its distance from its sun. Seager proposes a vast mechanical shade, roughly the shape of a star anise pod, that would be deployed in tandem with a space telescope, and laser-align itself with the scope to block out the light of a promising star, so that the light reflected from the planets in that solar system could be more directly detected.

(In the course of describing the Starshade program, a NASA Jet Propulsion Lab effort, Seager also demonstrated some neat JPL software, available at, which allows users to navigate the Kepler telescope imaged universe and access information about found exoplanets. She was quick to point out that the close-up graphics in the program are pure imagination. “We’ll probably never be able to see them that close.”)

Seager is an expert on methods of detecting the contents of distant planetary atmospheres through analysis of their reflected light spectra, as well as on the spectral signatures of gases associated with life.

Yet she readily admits the limits of the project. The new data it provides would be significant but still astronomically scant and insufficient to conclusively prove the presence of life. There are just too many variables -- too many sorts of stars, too many potential types of planets, too much potential for false-positives. Seager’s zeal was reflexively cautious.

Brand pressed gently, tried to get her to open up. He coaxed her into giving figures for the cost of the starshade.

“I’m just asking in case someone here has it,” he said, to guffaws.

He gathered her message together into an investor pitch.

“So it’s abut $20 million for the starshade, $150 million for the instruments and another $400 million or so for the spacecraft. That’s the sequence for anyone who wants an answer to the question of if there is other life in the universe.”

In the age of billionaire nerds committing treasure to cosmic initiatives, Brand identified the crucial data. True to form and live on stage, he did his best to smooth a scientist’s feathers and nudge her towards the crowd, a mediator role he’s grown fifty years of roots into. Perhaps, with his help, the starshade plan caught the golden gleam of some potential investor-cum-forebear of the galactic fleet.