This article discusses the recent astronomical discovery of the Bernardinelli-Bernstein Comet, one of the largest icy comets ever observed, using NASA’s Hubble Space Telescope. The focus of this discussion revolves around key features and characteristics of this unique discovery, as well as an overview of space technology as a whole and the critical role it plays in facilitating scientific innovations and discoveries.
The Bernardinelli-Bernstein Comet and NASA’s Hubble Space Telescope
NASA’s Hubble Space Telescope has helped astronomers confirm that the giant Bernardinelli-Bernstein comet, also known as C/2014 UN271, truly is the largest icy comet nucleus ever sighted. Almost 50 times larger than most known comets, its diameter stands at a staggering 129 kilometers, and its estimated weight is approximately 500 trillion tonnes.
NASA launched the Hubble Space Telescope in 1990. Named after Edwin Hubble, a renowned American astronomer from the early 20th century, this space-based observatory has contributed significantly to understanding interstellar objects, observing moons circling Pluto, and even witnessing a comet colliding into Jupiter.
Discovering the Bernardinelli-Bernstein Comet
Astronomers Pedro Bernardinelli and Gary Bernstein discovered the comet named after them in archival images from the Dark Energy Survey conducted at an astronomical observatory in Chile. Since its discovery in November 2010, the comet has been closely studied. Originating from the Oort Cloud, it has journeyed towards the sun for over a million years.
The Oort Cloud, a theoretical concept hypothesized by Dutch astronomer Jan Oort in 1950, is believed to be a distant region of the solar system that is the source of most comets. The comets constituting the Oort Cloud however, remain too faint and distant for direct observation.
Key Characteristics of the Comet
The Bernardinelli-Bernstein comet follows a 3-million-year-long elliptical orbit and maintains an estimated temperature of minus 348 degrees Fahrenheit. This temperature allows carbon monoxide (CO) to sublimate from the surface and produce the dusty coma surrounding the comet.
Understanding Comets
Comets, large objects made of ice and dust that orbit the Sun, are commonly known as ‘dirty snowballs’. Their composition includes dust, rocks, and ice, and they can range in width from a few miles to tens of miles. As comets orbit closer to the sun, the heat leads to the release of debris consisting of dust and gases. These solid portions, consisting mostly of water, ice, and embedded dust particles, remain inactive when far from the sun. As they draw closer to the sun, the icy surfaces vaporize, ejecting large quantities of gas and dust which form the atmosphere and tails of these celestial bodies.
Origins of Comets
NASA states that while there are millions of comets orbiting the sun, there are over 3,650 known comets today. Short-period comets, which take less than 200 years to orbit around the sun, are found in the Kuiper belt. Halley’s Comet, one of the most famous short-period comets that reappears every 76 years, will return next in 2062.
Long-period comets, with less predictable orbits, come from the Oort cloud which is about 100,000 AU from the sun. Comets in this cloud can take as long as 30 million years to complete one rotation around the sun.
Asteroids Versus Comets
A common question in the field of astronomy pertains to the difference between asteroids and comets. Asteroids, smaller rocky objects that orbit the Sun, are primarily found in the main asteroid belt located between Mars and Jupiter. Comets, described as cosmic snowballs of frozen gases, rock, and dust, spew dust and gases into a giant glowing head when close to the Sun, forming a tail that stretches millions of miles. Most comets orbit the Sun from the Kuiper Belt or the more distant Oort Cloud.