NASA launched the next-generation Nancy Grace Roman Telescope on August 30th. With the size of a big school bus, and weighing as much as a Tyrannosaurus Rex, Roman will explore the universe like never before.
The telescope is named to honour NASA’s first head of Astronomy, the trailblazing Dr. Nancy Grace Roman who is lovingly also called the mother of Hubble, because of the instrumental role she played in making the Hubble space telescope a reality. Incidentally, Roman’s primary mirror measures 2.4 metres, exactly the same a Hubble but 80% lighter due to new technology.
Roman has a 300-megapixel wide imaging instrument, allowing it to capture 100 times larger field of view than Hubble in a single infrared image. This unique capability will allow Roman to survey the sky quickly, and make new discoveries in many domains of astrophysics and cosmology.
Hubble played a pivotal role in throwing light on the dark universe. While it had been known for a while that the ubiquitous dark matter kept the structures together due to gravity, Hubble’s most remarkable discovery was that the universe is not just expanding, but expanding at a rate which is becoming faster and faster as time goes on due to a mysterious force astronomers dubbed dark energy.
Roman will make several observations to unravel the properties of the dark components of the universe, and help astronomer’s understand them better. During the first 5 years of surveys Roman will study minuscule changes in the shapes of millions of galaxies caused by dark matter present in between the objects and the telescope. Just like light bends when passing through different materials, light changes its path when passing through very dense mass. This distortion appears as change in the shape of very distant objects, and when combined for a large number of galaxies, the signal allows astronomers to map the invisible dark matter.
Roman will also observe around 21,000 type 1a supernovae explosions, allowing measurements of distance to the exploding stars and hence their host galaxies accurately. It will map billions of galaxies stretching back in cosmic time, allowing studies of formation of structures in the universe, and how they came together and assembled into the structures that we observe today.
The second key science contribution of Roman will come as its discovery of exoplanets. As of today we know of around 6,000 planets going around stars other than the Sun. Roman alone is likely to find at least 20,000 more due to its ability to see far and wide.
Roman is already moving towards its designated position around 1.5 million kilometres away from Earth, and scientists can’t wait to see what it sends back once it starts observing the cosmos with its new high-tech eyes. There is no limit to what Roman can discover, but rest assured, it will not just show us what we think, but may also open doors to new physics that we do not yet know we need.
