In this series of posts, we sit down with a few of the keynote speakers of the 241st AAS meeting to learn more about them and their research. You can see a full schedule of their talks here, and read our other interviews here!
Rocket launches can be a nerve racking time – especially when the payload is a 10-billion-dollar telescope like JWST. Unless you are Dr. John C Mather: “I wasn’t worried. We were doing everything we should be doing. We went through an immense number of tests. If there was still a fault, I would have had no idea how it got by us. But there was not, everything worked as planned.” While millions of others looked on with excited trepidation last Christmas, Dr. Mather was one of few people who had been able to bear witness to the thousands of hours of effort, energy, and execution put into building this telescope from scratch.
As Senior Project Scientist Dr. Mather has been uniquely situated to see each step forward, each part assembled, each checkbox ticked-off on the miles of to-do lists – the launch being just another well-rehearsed step in putting a telescope protected by a tennis-court-sized sunshade a million miles past midnight. “We actually spent two years of rehearsal with what I call the digital twin. It’s a complete computer simulation of everything that the observatory does except putting the astronomy through the actual camera.”
During our brief interview, Dr. Mather described the process of interfacing with the JWST engineers: “I worked with scientists to say this is what we need, chaired many generations of science teams, and I went to a lot of meetings.” These meetings produced an entire book of scientific requirements, which were translated into engineering requirements. “We identified 10 new inventions required in order to build this miracle. Engineers agreed that they could do it, and they could, but it took more work than people imagined.”
If not the launch, when did Dr. Mather celebrate? “We did have an unveiling ceremony on the day that the engineers said ‘we think we got it focused’. They took a big nice long exposure of a nice field of view to demonstrate this. Then they invited a lot of people including me to come watch the unveiling. When we saw the picture we could see that not only is the telescope focused but there are galaxies everywhere. People gasped. It was a big deal, we had champagne, and we had a party and congratulated ourselves. We were thrilled with the hardware, and our ability to work it.”
Career of Observations
While The excitement and success of JWST has been drawing international headlines, this is only the most recent experiment Dr. Mather has worked on. Dr. Mather has had a remarkable career, including a Nobel Prize!
As a child he was inspired by a meteorite at the American Museum of Natural History. “As a little kid you are concerned about those things, how did rocks fall out of the sky?” He started reading everything he could about astronomy and telescopes. “In a few years I was all wound up in electronics and vacuum tubes and telescopes.” Growing up on a research farm for Rutgers University, he relied on the bookmobile: “The county library sent a bookmobile around to the farms every two weeks, so I asked them to get me the amateur telescope makers series from Scientific American. I read every article over and over.”
Dr. Mather’s academic career began at Swarthmore and then went on to Berkeley, moving through a variety of topics, until he had to settle on a thesis topic. “They were just beginning to study the cosmic background radiation. (CMB)” He worked with Mike Werner, in the labs of Paul Richards, to build an instrument to measure the CMB from the ground, and then with Paul and David Woody to create a balloon payload to study the full spectrum. “That was my main thesis project. We flew it, and it did not work.” But he had enough to write up his thesis and “escaped” to a job at the Goddard Institute for Space Studies in New York City.
While Dr. Mather was working at Goddard, NASA made a call for new satellite missions in 1974. Wanting to give his failed thesis project another try, he worked with others to put in a proposal that eventually became the successful COBE mission. It launched in 1989, and “within weeks we knew we had great stuff.” The COBE results won the Nobel Prize in 2006, and an impressive trip to Stockholm with his family and colleagues.
Throughout his career, Dr. Mather has pushed the boundaries of his understanding. “Every experimenter has the same big problem: ‘How do I know I got it right?’ Nature can fool us in so many ways, and our own eagerness to see something can fool us in so many ways.”
Despite this nagging question of uncertainty, Dr. Mather’s science is driven by the pursuit of the unimaginable “If you want to have fun, you want to work on some projects that are on the edge of impossible.”And the edge of impossible includes the risk of failure. Alongside his list of accomplishments are projects or first attempts that have failed, including setbacks in COBE and JWST before their eventual brilliant successes. “That’s a way of carving a path that is kinda fun. But it can also be very frustrating. You have to have some safety and perspective. You can’t do it just everywhere.”
With JWST now successfully deployed, Dr. Mather already has his next list of impossible problems lined up. One such idea pairs the ground-based Extremely Large Telescope with space based star shades (to help block starlight and image exoplanets) and an orbiting laser guide star (to help with photometric calibration and adaptive optics). “In a way, this all comes back from my frustration with the blurry atmosphere that I’ve known about since childhood.”
What can we expect to hear at Dr. Mather’s AAS plenary? “I want to thank the huge number of people that contributed to the [JWST] mission in so many ways. Some pictures and names, a little bit of history, what did it take to do this against all odds, and what are some of the most exciting results that we’ve gotten so far. And at the end, why do I think we can build the next generation telescope, when it seems impossibly difficult.” See Dr. Mather’s full talk on Thursday January 12th at 8:10 am PT.
Astrobite Edited by Ryan Golant
Featured image credit: American Astronomical Society