Edward Moses has just been named president of the Giant Magellan Telescope Organization (GMTO), the 11-institution consortium that will build the world’s largest telescope in the Chilean Andes. Moses was previously principal deputy director at Lawrence Livermore National Laboratory, where until last year he was director of the National Ignition Facility (NIF). Combining seven 8.4-meter mirrors to form a 25.4-meter telescope, the GMT will have a light-gathering capability 10 times greater than any existing telescope when it comes on line in the early 2020s. Physics Today spoke to Moses on 8 September. Following is an edited transcript of the conversation.
Edward Moses. CREDIT: Lawrence Livermore National Laboratory
PT: Why did you leave Lawrence Livermore? Didn’t you want to stay to see the National Ignition Facility achieve ignition?
MOSES: I’m sure NIF will achieve ignition. I’ve never doubted that. My goal was always to enable the capabilities of the new generation of high-density science, which also includes ignition, and we built the laser, finished all the laser diagnostics and cryogenic system and everything you needed to do that mission. I was there over 10 years and that’s a long time for anyone to stay at any project. I thought it was time to move on to new work. They have excellent leadership with Jeff Wisoff. We did do very well on all those NIF missions. We got to the edge of [ignition]. We had what some people call scientific breakeven or hot-spot ignition, and I was very happy about that.
PT: What makes you a good fit for this job?
MOSES: I’ve always been interested in light, since very early in my youth. My first word after mama and papa was light, believe it or not. I have always been in lasers and optical systems. I worked for a while on the earliest adaptive optics in the 1980s and have managed big science programs of various kinds for the last 30 years, especially in optical systems and optic space systems, the AVLIS and NIF programs, this feels like a natural for me. Also I’ve been reviewing telescope projects for years.
PT: Are lasers used for the adaptive optics?
MOSES: Different temperature patches in the atmosphere have different densities and it’s sort of like a jiggly moving lens. If you take a laser and shine it onto the sodium layer that’s high in the ionosphere … you have a point source of light high in the atmosphere. You can use that to diagnose the telescope lens rapidly and put high-speed changes in your optics that will correct that. It’s like putting time-dependent glasses on the telescope. You kind of take the atmosphere out of the game, except for absorption, and you really change the nature of modern astronomy. This telescope is being designed from the get-go with advanced adaptive optics as part of its mission. I think that is a first for a big telescope. It will take light from a very large collecting area without the adaptive optics to a very large coherent imaging system. One of the reasons people would like to do that is so when you are looking at the atmospheres of exoplanets that are backlit by starlight, with this imaging system you could now do spectroscopy of the atmosphere and look for hopefully telltale signs of life that exist on those planets.
PT: That’s what the James Webb Space Telescope is supposed to do too, isn’t it?
MOSES: The James Webb is a little bit different. It’s an infrared telescope. Because it’s in space, it can not only be a large telescope that has no atmosphere to correct, but it can be very cold. You can do better infrared spectroscopy and imaging than you can do on Earth. We’re not competing with the Webb. They will have a unique capability. We’ll be complementary.
PT: How much is the telescope going to cost?
MOSES: Right now it’s at approximately $1 billion. That looks like a reasonable expectation; it’s been reviewed extensively. The preliminary design review was finished about 3 months ago. Besides the PDR, the major technical challenge people were concerned about was whether you could do these 8.4-meter optics with an off-axis grind. The University of Arizona mirror lab has done an 8.4-meter mirror, but never with the off-axis element to it. Now it’s been done successfully.
PT: Who is paying for the telescope?
MOSES: The partners are paying for this. This is the first privately funded coalition to build an astronomical observatory of this scale. This is not a federally funded project. NSF put in $10 million to help do the first mirror feasibility as part of their decadal investment in astronomy. One of the things that drew me to the project very strongly was having these high-quality universities and institutes around the world that have the confidence in the mission and the capability to invest their own money in it to the tune of $500 million.
PT: Are they contributing equal shares?
MOSES: The share will roughly be equal. The 501c3 [nonprofit organization] GMTO is forming a limited liability corporation that will be responsible for managing the funding and the effort. I’m the president of that company.
PT: Has the $500 million been contributed or committed?
MOSES: It’s a billion-dollar-scale project, and half the money has been committed.
PT: Where will the other half come from?
MOSES: Over time, a lot of other institutions are showing interest in joining. They’ll bring in funding, and maybe if we’re lucky as we get going, the founding partners and the joining partners will add more. It’s such an unusual situation to have a very large-scale project privately funded, and other institutions might be interested in having their names attached to this.
PT: Why does GMTO need both a president and a director? Who is the top guy?
MOSES: I think the director, Pat McCarthy, not only is a great astronomer but has been driving this process along the way. He and I will work together. As it moves into the project and construction phase, that’s something where I have more experience, so he and I are partnering. I’m the top guy, but I don’t think about it that way. I think of us as partners. My responsibility will be on the design, procurement, construction, and commissioning of this project. We have a science advisory committee, a lot of stakeholders, and we’re trying to make sure we stay parallel and consistent with their needs, make sure they know what we’re doing, so if they have suggestions, we take care of them.
As scientists scramble to land on their feet, the observatory’s mission remains to conduct science and public outreach.
November 18, 2025 12:49 PM
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