4 billion-year-old Comet with heart ‘blacker than coal’ heading towards Earth, know more - The interstellar BB comet is so huge that it was earlier mistaken to be a dwarf planet.
Images of C/2014 UN271 – a comet 128km in diameter and completing an orbit of the sun every few million years – were captured by the Hubble Space Telescope.
C/2014 UN271 (Bernardinelli-Bernstein) was discovered by astronomers Pedro Bernardinelli and Gary Bernstein in archival images from the Dark Energy Survey at the Cerro Tololo Inter-American Observatory in Chile. With a diameter of approximately 80 miles across, the comet is about 50 times larger than typical comets and its 500 trillion ton mass is a hundred thousand times greater than a typical comet found much closer to the Sun.