If all goes to plan, at 7:26 a.m. Sunday morning, a new space telescope will blast off from Cape Canaveral, Fla., on top of a Falcon Heavy rocket, ready to reveal new wonders about our universe.
The highly anticipated Nancy Grace Roman Space Telescope is named after NASA’s first chief astronomer, also known as the “mother of the Hubble Space Telescope.” Once launched, it will orbit 1.5 million kilometres away, at a point called L2 where gravitational forces balance to keep satellites in a steady orbit. It is a five-year mission, with the possibility of extension.
But why bother adding a new telescope to the arsenal of telescopes already in orbit, like the Hubble Space Telescope or the James Webb Space Telescope?
Because each telescope is equipped with different instruments, and Nancy Grace Roman is no different. While it has a mirror that is roughly 2.4 metres across, similar to Hubble, it also has a coronagraph that can block out starlight to reveal planets orbiting distant stars. It also has its Wide Field Instrument that is just as sensitive as Hubble’s but has the ability to image an area 100 times larger. It’s like going from looking through a pinhole to something the size of a golf ball.
Its camera will be able to resolve billions of stars, allowing for all different types of sky and stellar surveys.
So, what makes Nancy Grace Roman so special? Let’s take a look at just some of the highly anticipated discoveries astronomers are hoping this telescope will make.
The search for other planets
While we don’t know of any other planets with life, astronomers are continuing to investigate other stellar systems to find out what makes our solar system so unique. Or perhaps it’s not that unique.
To date, more than 6,300 exoplanets have been confirmed, mostly from the Kepler Space Telescope.
There are a few ways to look for exoplanets. The most popular is the transit method, where a telescope looks at a star for an extended period of time. If there’s a planet that crosses — or transits — in front of it, the light of the star dips ever-so slightly. And that’s what Nancy Grace Roman will do as well. But on a much bigger scale.
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“It’s just going to be crazy how much more we’re going to learn because right now you know we’ve got Kepler, which I guess we looked at, like, 200,000 stars or something like that, and then with Roman we’re going to look at 100 million stars and we’re going to go from 10,000 planets to 100,000 transiting exoplanets,” said Kelsey Hoffman, a co-investigator on one of the observing programs with the telescope and a researcher at Bishop’s University in Sherbrooke, Que.
“So that increase in numbers, it’s… I can’t even imagine what we’re going to learn.”
But the telescope will also use another method to search for exoplanets — something called microlensing, which allows astronomers to peer even deeper.
“If you have a distant star that you like to call a source of light, and then a star with its planets moves precisely right in front of it, that mass of the star and the mass of the planet act as two lenses, and causes the light that’s coming from that distant star to bend a little bit, which we observe as a magnification event,” explained Jason Rowe, who is also part of a Nancy Grace Roman observing program and is a professor in the department of physics at Bishop’s University.
He’s particularly excited because this type of observation will allow scientists to look for more Earth-like planets.
“We’ve discovered previous planets with microlensing, but we’re going to kind of blow the doors open and now discover a very large sample of them,” he said. “And microlensing is very sensitive to planets at longer periods, including those that have masses about Earth’s size, about Earth masses.”
Dark matter and dark energy
What we are able see makes up only five per cent of what exists in the universe. Roughly 27 per cent is dark matter, a sort of invisible glue that holds the galaxies and the stars within them together. The other 68 per cent is dark energy, also invisible, and something that is believed to speed up the expansion of our universe.
Astronomers have been trying for decades to figure out exactly what dark matter is, and Nancy Grace Roman will look for dark matter within galaxies and within beautiful globular clusters, a collection of thousands to millions of stars that are all tightly gravitationally bound.
The mission will measure the locations and amount of dark matter, as well as normal matter, in hundreds of millions of galaxies.
“Normally with surveys, you have this trade-off where you decide, am I going to stare out one little patch for a very long time? Or am I gonna scale across the sky?” said Nicole Drakos, an astrophysicist at the University of Hawaii, Hilo, who is also part of a Nancy Grace Roman observational program. “With Roman, you can stare at one patch on the sky, but you still have an enormous area.
“So you can see these distant galaxies, but also see where they live. You can see their environment. You can map out the dark matter structure around them, the gas around them.”
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The telescope will also investigate dark energy, which, like dark matter, is invisible. But in this case, dark energy is causing our universe to expand rather than slow down.
“I’m, you know, involved with the deep field stuff, so I’m obviously interested in that. But, you know, in my heart, I am a cosmologist; I really love the cosmology,” Drakos said. “Getting a better handle of things like the expansion of the universe, I think, is really cool.”
