Shades of Mediocrity

This video of the Eagle Nebula showcases Roman’s superb resolution and wide field of view. It begins with a Hubble image of the famous Pillars of Creation superimposed on a ground-based image. The view then zooms out to show the full field of view of Roman’s Wide Field Instrument. Roman’s images will have the resolution of Hubble while covering an area about 100 times larger in a single pointing.

Roman will pair a large view of space with infrared heat vision. That combination is a game-changer for studying nebulae.

Here’s how it usually works. Ground-based telescopes take large but somewhat blurry images of a nebula. Then space-based observatories like our Hubble and James Webb space telescopes zoom in on small patches to show us the details of particularly interesting regions. But with Roman, we’ll get the big picture and incredible detail all in one.

That saves astronomers a lot of time, which opens up new avenues of exploration. For example, instead of spending several months stitching together hundreds of individual images of the Orion nebula with Hubble or Webb, Roman could cover it in a matter of hours in just a few snapshots.

Roman’s vast surveys will give us a census of stellar nurseries, where fledgling stars are being born from parent clouds of gas and dust. Studying these nebular nesting grounds will reveal millions of stellar embryos, newborn stars still swaddled in shrouds of dust, toddler stars that throw tantrums and flare unpredictably, and young stars that may have planetary systems forming around them.

A single Roman survey of our Milky Way galaxy will capture thousands of nebulae, unveiling planet formation and the full lifecycle of stars like never before. That includes their spectacular final acts.

This Hubble image showcases the Hourglass nebula, a young planetary nebula located about 8,000 light-years away.

Garden-variety stars like the Sun live fairly placid lives, casually churning out heat and light for billions of years by fusing hydrogen into helium. That nuclear process creates a lot of energy and outward pressure. For a long time, it’s held in check by the inward pull of gravity. But when a star runs out of fuel to fuse, gravity takes over.

Their cores shrink so fast that their outer shells of gas are left behind, which puff out and transform into unique and often psychedelic works of art called planetary nebulae (so-called because they looked similar to planets in early telescopes). Heftier stars meet more dramatic fates, with a runaway reaction that leads to the star’s detonation: a supernova explosion! Both result in nebulae that look like kaleidoscopic dreamscapes.

This image of supernova remnant W49B combines X-rays from NASA’s Chandra X-ray Observatory in blue and green, radio data from the NSF’s Very Large Array in pink, and infrared data from Caltech’s Palomar Observatory in yellow.

Star deaths create conditions so extreme that it can form new elements. The iron, oxygen, magnesium, silicon, sulfur, and nickel that together account for around 96% of the Earth's bulk were flung into space by supernova explosions. And some of the elements that make up your DNA, like carbon and nitrogen, were forged by smaller dying stars. You are literally made of stardust!

Roman will help us learn more about how elements were created and distributed throughout the galaxy, all while exploring many other cosmic questions.

This artist’s concept visualizes visible light in blue, showing how its short wavelength means it will easily run into dust particles. Longer wavelength infrared light, visualized in orange, can more easily pass through dust.

Roman’s infrared vision is key, because it will allow astronomers to see through the dust that often blocks telescopes that view other types of light. It’s hard for visible light to penetrate this dusty haze because the particles are the same size or even larger than the light’s wavelength. Since infrared light travels in longer waves, it hardly notices the tiny particles and can pass more easily through dusty regions.

By seeing through dust, we'll get a far better view of stars and other objects that are in nebulae and the cosmic structures that lie behind them. Astronomers will soon be able to chart our galaxy like never before!

An artist’s concept based on the final design of NASA’s Nancy Grace Roman Space Telescope.

We’re only about a month out from launch, and so close to a completely new understanding of the universe and our place within it. Follow along with Roman’s road to launch at nasa.gov/roman, and virtually tour the Roman observatory here.