The article begins with the discussion of a recently discovered comet named C/2020 F3, also known as NEOWISE, scheduled to make its closest approach to Earth on 22nd July 2020, at a distance of 64 million miles or 103 million kilometres. The comet was discovered by the National Aeronautics and Space Administration’s (NASA) telescope.
Discovery and Appearance of Comet C/2020 F3
On 3rd July 2020, the comet made its closest proximity to the sun at 43 million km, which led to the release of its outer layer, creating a sphere of gas and dust commonly known as coma. This occurrence stemmed from the icy surface of the comet, and it became visible initially through binoculars or a small telescope.
Understanding Comets
The term ‘comet’ originates from the Latin word ‘Cometa’ suggesting ‘long-haired.’ The first recorded sighting of a comet dates back to 1059 BC by an astrologer. Comets, often referred to as “dirty snowballs,” predominantly consist of dust, rocks, and ice, varying in sizes that span a few miles to tens of miles wide. While orbiting closer to the sun, such as C/2020 F3, comets often heat up, resulting in dust and gases debris.
Orbiting and Appearance of Comets
The solid portions mostly comprise water, ice, and embedded dust particles. These elements remain inactive when the comet is distant from the sun. However, when in proximity to the sun, the cometary surfaces vaporize, emitting large quantities of gas and dust, thus constructing an enormous atmosphere and tails. Consequently, the released gases form a glowing head, larger than a planet at times, while the debris shapes a tail that can extend up to millions of miles. Each instance a comet passes the sun, it loses some of its material, and its disappearance is eventual.
Comets’ Journey
Occasionally, comets can be nudged into orbits closer to the Sun and Earth due to gravitational forces. Currently, NASA confirms over 3,650 known comets among millions orbiting the sun. The predictable short-period comets take less than 200 years to orbit around the sun and can be found in the Kuiper belt – the realm of Pluto. The world-renowned short-period Halley’s Comet, reappearing every 76 years, will next be visible in 2062.
Comets and Visibility
Comets do not possess their own light, and visibility relies on their gas and dust outbursts. The reflection of the sun’s light off the comet in combination with the absorbed energy released by the gas molecules from the sun give rise to human visibility. For a comet to be perceptible, it must either approach exceptionally close to the sun to produce abundant gas and dust or make a relatively near approach to Earth for easy viewing.
Study Significance and NASA’s Role
Astronomers conceive comets as critical clues towards understanding the development of the solar system. They also hypothesize the potential role of comets in bringing water and other organic compounds to Earth. NASA tracks all Near Earth Objects (NEOs), including comets and asteroids, via telescopes stationed worldwide as part of its NEO Observation Program. The program’s objective entails the detection, tracking, and characterizing of large-scale NEOs, which pose a possible risk to Earth due to the potential devastation an impact could cause.
