RESOLVING THE LEDGER
This is one outlet's own report from Scientific American — the article as it was filed. Other outlets are covering the same event; open the full story to compare every source side by side.
See the full story · 29 sources
NASA launches Roman Space Telescope to uncover the universe's biggest mysteries
NASA's Nancy Grace Roman Space Telescope is on a mission to probe dark energy, hunt for distant worlds and transform our view of the universe
Rachel Feltman: Happy Monday, listeners! For Scientific American' s Science Quickly, I'm Rachel Feltman. We're kicking this week off by focusing on one major science news story: the launch of NASA's next great space observatory.
Early in the morning on Sunday, August 30, the Nancy Grace Roman Space Telescope launched from NASA's Kennedy Space Center in Florida on a SpaceX Falcon Heavy rocket. It's now on a month-long journey to a spot known as Lagrange Point 2, or L2, which is more than 900,000 miles away from Earth.
Our guest today is Julie McEnery, who serves as senior project scientist for the mission. She's here to tell us why scientists are so excited about this new space telescope and what it could teach us about the universe.
If you're enjoying this article, consider supporting our award-winning journalism by subscribing . By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Thank you so much for coming on to chat with us today.
Julie McEnery: It's a pleasure to be here.
Feltman: So how long has this telescope been in the works?
McEnery: If you start the clock when scientists first started imagining "What kind of mission would you want to put together to explore the newly discovered accelerating universe?" it starts in the early 2000s.
Feltman: Well, and so let's take a step back for our listeners to talk about that. You know, what discoveries led scientists to want an observatory with these capabilities? You know, what questions were they starting to get excited to answer?
McEnery: Well, there's three separate questions. So one of the most prominent was the discovery that our universe is accelerating. The idea that our universe is accelerating is crazy, right? What you know about in the universe is that the universe has matter, and gravity acts on matter, and it pulls it together. We would expect our universe to continue expanding at a constant rate or to even start to contract. When we went to measure how the universe is expanding as a function of time, we discovered that it's actually accelerating, and that's as crazy as if you were to throw a ball in the air, and instead of the ball coming back down, it accelerates out of there. So one of the reasons for Roman was to build an observatory that was going to be able to measure that phenomenon much, much better.
At the same time, the study of exoplanets, planets around other stars, was exploding. And one of the things that scientists wanted to do was to be able to design an observatory that could find a large number of exoplanets that were at large distances from their host stars using a technique called microlensing. And that technique requires a mission with a wide field of view and a good sensitivity.
And then there were also a group of scientists who were really interested in the science that you could do if you had wide-field, near-infrared surveys. And it turns out that a mission that gives you exquisite performance, exquisite sensitivity and an ability to conduct wide-field surveys in the near-infrared could address all three of those science questions, and that's how Roman was born.
Feltman: Wow. So to accomplish all of these things with an observatory, what does its instrumentation need to be capable of? You know, what kind of technological hurdles did NASA face with this mission?
McEnery: So we needed a couple of things. We needed to have an optical design of the telescope itself, the optics in the telescope, that would allow you to have a large field of view with good optical performance.
That's reasonably well understood. It's a matter of, uh, building it. We needed to build a large camera that had the ability to have very fine pixels, that was exquisitely sensitive. We want to be able to—say, if you imagine looking at a star and measuring how bright it appears, that the next time you go back, you're measuring exactly the same brightness, that your instrument itself is staying perfectly stable. So we wanted to design the camera for our telescope that had very fine pixels, that was very sensitive and was very stable. And we did that by working with Teledyne to design a new generation of improved detectors and by in-house developing new readout chips that could control those detectors, in a very stable, low-noise way.
And then the final thing that we needed to do is we needed the observatory itself to be extraordinarily stable. Roman is the most stable telescope that NASA has ever built. The telescope itself is, is really beautiful. It's built to extraordinarily high precision. The rest of the observatory, every single aspect of the design has considered stability. So we have thought about: Well, if you move the high-gain antenna, what's gonna happen? The stability of the observatory. If we slew from one place to another, what's gonna happen? The stability of the observatory. If we slew from one place to another with the sun in a particular direction, we understand what's going to happen, and that has informed all of our design choices so that we've ended up with a really beautiful observatory.
Feltman: I would love to talk about where the observatory is headed in space. I love talking about L2, so I would love to hear your explanation for why it's going to be where it's going to be.
McEnery: So the Roman is gonna travel a million miles from Earth to the sun-Earth Lagrange point. We will be in an orbit around that quasi-stable point, and it's a really great place to be. We're far enough away from the Earth and the moon that we don't look directly at them, but they don't block a large part of our vision. The sun is always in the same place on the observatory. We're not going through night and ...
AIPROPX is an independent multi-source news index — we track, compare, and connect coverage from across the web into one place you won't find anywhere else.