Are we alone?
It’s the ultimate question, but it’s also an impossible task.
“We could find signs of life, but it’s not going to be the definitive proof that we were hoping for when we started out on this journey.”
So says Professor Sarah Seager of the Massachusetts Institute of Technology, the pioneering planetary scientist, author of The Smallest Lights in the Universe and one of the main characters in director Nathaniel Kahn’s intriguing new documentary, The Hunt for Planet B.
Previewed recently at the 2021 SXSW Film Festival, this impressive film explores the development of the science of exoplanets—planets around other stars—and the search for extraterrestrial intelligence (SETI). It does so against the backdrop of the upcoming launch of the James Webb Space Telescope (JWST or “Webb”), the much-delayed $10 billion space telescope that’s due to launch on October 31, 2021.
You can’t go a week without an exoplanet making the news, whether it’s a rocky world with tantalizing parallels to Earth, a “super Earth” with a day that lasts forever or the discovery of a planet around the star that was the source of the alien signal in the movie Contact.
The Hunt for Planet B is the human story. It reveals a world of thinkers, dreamers and doers that dare to imagine what’s out there on exoplanets—defined as a planet outside the Solar System—and who build machines to find out more that take entire careers to complete.
It’s a story about dedication and collective effort over a long time period that’s largely for the benefit of the next generation of scientists. It’s got a stirring relevance to the global inaction on climate change.
Astronomy? Really? That’s just a bunch of old white men, right?
Astronomy is dominated by men. In fact, few fields have a greater gender imbalance. However, in the sub-genre of exoplanets—which was a super-niche at the turn of the century yet has arguably come to dominate astronomy in recent years—that’s not the case, the documentary suggests.
Seager, an expert on the atmospheres of exoplanets, has helped shape a new discipline within astronomy and hopes to use Webb to further push the boundaries. One of its first tasks will be to investigate “super Earths.” “These planets are two to three times the size of Earth and they appear to be the most common type of planet in our galaxy,” says Seager. “We don’t know what they’re made of , we don’t know how they formed and we don’t know how why there’s so many of them. Webb can observe their atmospheres very easily and we hope that will help inform us about what the planets are made of.”
Whether we’re alone as a species is a different question that Webb will struggle to answer, but The Hunt for Planet B makes it clear that Seager is not alone.
It reveals a cast of women that are leaders in exoplanet science; Natalie Batalha, project scientist for the Kepler mission that first revealed our night sky to be filled with more planets even than stars, Jill Tarter, former director of the Center for SETI Research, Maggie Turnbull, an expert on potentially habitable planets at the Global Science Institute, and Amy Lo, System Engineer for Webb.
How did this happen? The first exoplanet wasn’t confirmed until 1992 and even come the new century the hunt for these worlds was largely shunned by mainstream astronomers. The glass ceiling cracked.
“Back in 2001 I was at a big astronomy conference with many thousands of people and it seemed like all of the speakers were older men with white hair, but when it came to exoplanets there was was no-one old enough to have white hair,” said Seager. “There just weren’t any established older people because the field was so new. It was open to people coming in and there wasn’t any kind of set culture.”
Exoplanet science may have changed astronomy in unexpected ways long before we’ve even discovered an Earth 2.0, but it may be time to get further expectations in check.
Webb is not going to find aliens. Even with its 21 feet/6.5 meter-diameter primary mirror made up of 18 gold-plated beryllium hexagonal mirror segments.
For starters, it won’t be looking in the right place. “The whole field has shifted gears to focus on small red dwarf stars—we’re trying to do the easy things first,” said Seager. “Webb has a chance of identifying a habitable rocky world, but not around a Sun-like star—Webb is a frontier, but it’s not what some of us would call the ultimate frontier.”
Despite that, the success of Webb is absolutely critical to exoplanet science. In fact, it’s absolutely key not only to the future of exoplanet science, but to the future of big science in general.
Webb will change everything because it will see into the infrared—it will be able to look farther back in time and, crucially, more easily characterize the atmospheres of exoplanets.
“We don’t we don’t know what the discoveries will be,” said Matt Mountain, Telescope Scientist for Webb and a member of the Webb Science Working Group since 2002, who features in The Hunt for Planet B. “But in 20 years time I’m going to bet that three of Webb’s top 10 discoveries will be in exoplanets.”
But Webb is more fundamental even than that. “Webb is a pathway to doing new things in astrophysics—because we know things are fainter and smaller, and if we want to find life we’re going to need an even bigger telescope than the Webb,” said Mountain.
Webb sets the tone for the future of astronomy; the next generation of space telescopes have to be at least as large and at least as big as Webb.
But it’s a risk—and everyone involved is going to be nervous when it launches on October 31, then takes weeks to deploy.
Why is Webb such a risk?
While the Hubble Space Telescope orbits Earth from 550 km and was serviced by Space Shuttle astronauts five times, Webb will observe the Universe alone. From its position at the second Lagrange point (L2) around a million miles/1.5 million kilometers from Earth, it’s (probably) too far away to fix if something goes wrong. Webb is also the first deployable space telescope. Its 18 mirror segments must mechanically unfurl. It’s got to work—and work first time.
What if it doesn’t? “If Webb doesn’t work then there will be a huge loss of confidence—people will wonder if NASA should focus on other areas of science—and that’s why the film is so important,” said Mountain. “It shows a dedicated group of people working hard to choose to do this very audacious thing.”
As one one of the engineers in the film says, “this is the test of my lifetime.” “Many people put their whole careers into this telescope, which is a remarkable human thing to do, but these commitments are never risk-free,” said Mountain.
As The Hunt for Planet B gets across in a very human way, Webb is an engineering miracle that’s the result of decades of human endeavour, dedication and collaboration by over a thousand people.
“Science is very much a collective endeavor and building big machines like telescopes and particle accelerators takes a village—you need a remarkable group of people,” said Mountain. After all, Webb has been on the drawing board for 25 years. “You’ve got to admire the dedication of almost two generations of astronomers that have dedicated themselves to this telescope.”
In the film, Mountain is shown visiting Galileo Galilei’s house in Florence where he gazed at Jupiter and discovered its moons. But despite the Nobel Prizes often awarded to single scientists, that’s not how science works anymore.
“Designing Webb took the talent and dedication of the entire team and is the kind of challenge we all sought as engineers,” said Jon Arenberg, chief engineer for the Webb, who in an especially awe-inspiring section of the film is shown standing within the massive unfurled telescope during testing. “It’s an act of collective genius and knowing I was able to play a part in realizing Webb’s potential for humanity to view the universe in an entirely new way is the reason I became an engineer—I live for the chance to invent tomorrow.”
And exoplanet science is mostly about tomorrow. Webb and other telescopes will help scientists make incredible discoveries, but they will be but steps to even greater discoveries of the future. For this generation there will be no first contact, no confirmed extra-terrestrial intelligence, no bona fide Earth 2.0. That’s for the astronomers to come.
Revealing that the search for exoplanets and aliens is at its heart entirely a human story—and a hugely admirable one—The Hunt for Planet B has no conclusion. There are no hints of intelligent civilizations at the end, nor may there ever be. The film gives viewers a peek behind the curtains at how an amazing mission like Webb comes together, how it’s used to do science and the talented people bringing it to life.
It’s about dedicated people taking on an impossible task that they know must be attempted.
“It’s like a glimmer over the horizon, something we can’t quite reach,” said Mountain. “Webb will reach it.”
Wishing you clear skies and wide eyes.