Dark matter and dark energy make up 95% of the universe. Humanity has never discovered it directly. The Nancy Grace Roman Space Telescope, named after NASA’s first head of astronomy and the first woman to hold an executive position at the agency, recently reached a milestone: It’s complete.
At NASA’s Goddard Space Flight Center in Maryland, scientists and engineers gathered to celebrate the observatory’s moment of accomplishment, while its crisp illumination showcased the observatory’s beauty ahead of the upcoming mission.
NASA Nancy Grace Roman Space Telescope
Roman’s main mirror is also comparable in size to Hubble’s, measuring about 7.9 feet in diameter. However, when other similar characteristics are considered the difference between the two items becomes apparent. As NASA chief Jared Isaacman pointed out, the time it takes for Hubble to image an object can be done by Roman in under a year, which means Hubble works 1,000 times faster than Hubble by taking 200 times wider pictures of the sky.
Hubble has been in operation since 1990 and has collected approximately 400 terabytes of scientific data over its 35-year lifetime. On the other hand, Roman is estimated to generate 500 terabytes of scientific data per year once it becomes operational.
Roman’s Wide Field Instrument is a 300-megapixel visible-to-near-infrared camera equipped with a slitless spectrometer, with an image size 50 times wider than that of the James Webb Space Telescope. This is necessary because the instrument uses a wide coverage space to fulfill its mission of monitoring the sky and detecting fast astronomical events that would go unnoticed by smaller telescopes.
These include fast radio bursts, neutron star collisions, and supernovae. “We’re going to see thousands of supernovae, and some of them will be much more distant than any supernova we’ve ever seen before,” said Dominic Benford, program scientist for the Roman telescope, according to Space.com. “We will trace the history of the universe through exploding stars.”
The wide-field approach lets Roman create detailed three-dimensional maps of galaxy distribution, which scientists use as a primary tool to investigate how dark matter affects the structure of the universe.
Dark matter and dark energy represent the most fundamental elements of existence as they make up 95% of all matter and energy in the universe. Scientists have never observed either of these phenomena through direct observation. Scientists use dark matter to explain how galaxies maintain their structure despite violating established physical laws, and they use dark energy to explain the increasing speed of the universe’s expansion.
The Roman’s wide view of the sky gives him a practical advantage in this hunting. By rapidly imaging large numbers of galaxies, which can track how those galaxies coalesce and how the cosmic expansion has changed over time, scientists have two observational handles on the dark universe.
“We will study how the universe expanded over time,” said Julie McEnery, Roman’s senior project scientist. “These are the keys to unlocking the fundamental nature of dark matter, dark energy and the structure of the universe.”
Roman is expected to be launched into space using the SpaceX Falcon Heavy vehicle which has completed eleven successful missions so far. Roman is scheduled to head with the James Webb Space Telescope to Lagrange Point 2, in an orbit about a million miles away from the planet, where he will be cooled by sunlight while remaining in constant communication with mission control.
However, until then, Roman will have to undergo further tests and be flown to NASA’s Kennedy Space Center in Florida. Once these stages are cleared, Roman carries with it a coronagraph capable of imaging planets 100 million times fainter than their host stars, a capability 100 to 1,000 times greater than any existing space coronagraph, and an instrument that can produce the first direct images of Jupiter-like worlds orbiting the distant Sun.
McEnery suggested that the most important Roman discoveries may not yet be named. “The most exciting science from Roman will be the things we didn’t expect, that we couldn’t predict.”
