NASA’s Roman telescope will see 100 times more sky than Hubble

The Nancy Grace Roman Space Telescope is set to launch on Sunday, Aug. 30 from NASA's Kennedy Space Center in Florida. This new observatory will join Hubble and James Webb in their efforts to explore the vastness of space and potentially uncover answers to long-standing questions about the universe.

Roman has the unique ability to block starlight that obscures distant exoplanets, allowing scientists to reveal distant disks of dust and particles that eventually form new planets. Its primary goals are to create a statistical census of planetary systems within our Milky Way galaxy and to analyze the historical impact of dark matter and energy on the formation and evolution of normal matter in the universe.

In comparison to its counterparts, Roman stands out due to its wide-field imaging capabilities. Unlike Hubble and Webb, which often capture smaller patches of sky, Roman will be able to survey larger areas at once, covering a portion of the sky larger than the full moon in each image. This allows Roman to take in more data much faster than Hubble or Webb.

To put this into perspective, low Earth orbit, where Roman and other satellites reside, is about 0.25% the distance to the moon - roughly 500 to 2,000 kilometers (310 to 1,250 miles) above Earth. This is much higher than the cruising altitude of commercial flights, but still significantly closer to Earth than the moon.

While Roman offers promising advancements, the increasing prevalence of satellites in low Earth orbit has raised concerns among astronomers. With the potential for thousands to millions of satellites being launched in the coming decade, there is worry about how these objects may hinder our ability to observe the universe beyond Earth.

Moreover, light pollution on Earth's surface, caused by artificial upward-pointing lights, further obstructs our view of the night sky. While a few thousand stars can be seen with the naked eye in dark locations, this number is drastically reduced in areas with significant light pollution, such as New York City where only a dozen stars may be visible on a moonless night.

There are methods to mitigate light pollution, such as shielding lights, using timers or motion sensors, reducing the number of lights installed, and employing lights that emit more orange and red wavelengths rather than blue and white. Some regions, like France and parts of Australia, have successfully implemented these measures, resulting in skies up to 90% darker than in comparable communities.