Nasa launches telescope that will map two billion galaxies

On Sunday, NASA successfully launched the Nancy Grace Roman Space Telescope, a wide-field infrared observatory added to the expanding fleet of space telescopes aimed at addressing fundamental questions in astronomy. The telescope, named after NASA's first chief astronomer, Nancy Grace Roman, will map billions of stars and galaxies, search for approximately 100,000 exoplanets, and collect crucial data to better comprehend the roles of dark matter and dark energy.

Roman's primary advantage lies not only in its resolution but in the vast amount of sky it can cover in a single observation. With a 2.4-meter primary mirror and an advanced Wide Field Instrument, the telescope boasts a field of view up to 100 times larger than Hubble's and can survey the sky up to 1,000 times faster. A single full-resolution Roman image would require more than 500,000 high-definition television screens to display, covering about 0.28 square degrees of sky at a time, which is more than the apparent area of the full Moon.

The telescope's Wide Field Instrument operates in the visible wavelengths to near-infrared range, enabling it to pierce through dust and detect distant, redshifted galaxies. Equipped with eight imaging filters, a grism, and a low-resolution prism for slitless spectroscopy, Roman will gather spectral data across extensive sections of the sky. The telescope's primary science objectives include investigating the universe's accelerated expansion, mapping the distribution of matter, and identifying exoplanets.

Roman will primarily focus on understanding the universe's accelerated expansion, known as dark energy, which remains unresolved. The telescope will also aid in mapping the distribution of matter across the universe, providing a more detailed view of its structure. Exoplanet research will be another major component of the mission, using gravitational microlensing to identify planets that are otherwise difficult to detect.

Roman's findings could help researchers understand the prevalence of planets around different types of stars and at varying orbital distances. The observatory also includes a Coronagraph Instrument, which tests the telescope's ability to directly image planets and debris disks around stars.