Context: Recently, National Aeronautics and Space Administration’s (NASA) Hubble Space Telescope has confirmed that the huge Bernardinelli-Bernstein comet is indeed the largest icy comet nucleus ever seen by astronomers.
About Bernardinelli-Bernstein comet

• The comet was discovered by astronomers Pedro Bernardinelli and Gary Bernstein in archival images from the Dark Energy Survey at an astronomical observatory in Chile.
• It was discovered by chance in November 2010 and has been intensively studied since.
• Stretching about 80 miles (129 kilometers) across, the nucleus (or solid center) of the comet, known as C/2014 UN271 (Bernardinelli-Bernstein), is larger than the state of Rhode Island, and it's about 50 times larger than the average comet core.
• The Bernardinelli-Bernstein comet has been travelling towards the sun for over a million years and it is believed to have originated in the Oort cloud, a distant region of the solar system that is predicted to be the source of most comets.
• The Oort cloud is still only a theoretical concept as the comets that constitute it are too faint and distant to be directly observed.
• It was first hypothesised by Dutch astronomer Jan Oort in 1950.
• The Bernardinelli-Bernstein comet follows a 3-million-year-long elliptical orbit and has an estimated temperature of minus 348 degrees Fahrenheit – warm enough to sublimate carbon monoxide from the surface to produce the dusty coma.

Is the comet a threat?

• It is unlikely that the Bernardinelli-Bernstein comet can become a threat to the earth.
• It is travelling at a speed of 22,000 miles per hour from the edge of the solar system towards us, but it will never get closer than one billion miles away from the sun.
• That is a little farther than the planet Saturn, and even this situation is not likely to occur till 2031.

Hubble Space Telescope

• The Hubble Space Telescope was launched by NASA in 1990 and is named in honour of Edwin Hubble, a revered American astronomer of the early 20th century.
• The telescope is a space-based observatory and has made significant observations related to interstellar objects, including moons around Pluto and a comet crashing into Jupiter.
• The telescope has now been in operation for over thirty years.