In news– Recently, NASA’s Hubble Space Telescope has confirmed that the huge Bernardinelli-Bernstein comet is indeed the largest icy comet nucleus ever seen by astronomers.
About the comet-
- Officially called the C/2014 UN271, this comet has an estimated diameter of almost 129 kilometres.
- The nucleus is around 50 times larger than that of most known comets, and its mass is estimated to be around 500 trillion tonnes.
- It was discovered by astronomers Pedro Bernardinelli and Gary Bernstein in archival images from the Dark Energy Survey at an astronomical observatory in Chile in November 2010 and has been intensively studied since.
- The 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.
- This 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.
- The challenge of measuring the size of this comet was to separate its nucleus from the coma – an envelope of dust surrounding the nucleus.
- It is travelling at a speed of 22,000 miles per hour from the edge of the solar system towards earth, 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.
The Hubble Space Telescope-
- It 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.
- The Space Telescope Science Institute (STScI) selects Hubble’s targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft.
- Hubble is the only telescope designed to be maintained in space by astronauts.
- One successor to the Hubble telescope is the James Webb Space Telescope (JWST) which was launched in 32021.
What is a Comet?
- Comets are large objects made of dust and ice that orbit the Sun. Best known for their long, streaming tails, these ancient objects are leftovers from the formation of the solar system 4.6 billion years ago.
- Comets are mostly found way out in the solar system. Some exist in a wide disk beyond the orbit of Neptune called the Kuiper Belt which are called short-period comets.
- Other comets live in the Oort Cloud, the sphere-shaped, outer edge of the solar system that is about 50 times farther away from the Sun than the Kuiper Belt.
- These are called long-period comets because they take much longer to orbit the Sun.
- The comet with the longest known orbit takes more than 250,000 years to make just one trip around the Sun.