Wandering star has long tail to tell - 10th August 2020

The heavens have been graced with the spectacle of an additional fiery body this July. This fleeting visit by Comet Neowise, whose orbit brought it close to Earth as it began its journey away from the sun, could be appreciated by amateur stargazers and the general public across the northern hemisphere.

Neowise is a rare example of a comet visible to the naked eye. These cosmic snowballs formed of frozen gases, rock, and dust grow radiant, flaming ‘tails’ of gas when heated as they near the sun.

Passing closest to Earth at a distance of 103 million kilometres on 23rd July, the comet remained 400 times further from the planet than our moon and could be observed close to the horizon. Its burning tail pointed up behind it, making it easy to detect among the stars and planets glimmering in the night sky.

Aboard the International Space Station, astronauts remarked that the comet, which appears much more clearly beyond Earth’s atmosphere with its long tail shining brightly, was the most luminescent to be seen for some years.

Comet Neowise takes its name from NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, the instrument designed to detect near Earth objects which had identified the comet in March this year. At approximately five kilometres in diameter, Neowise is of average size for a comet.

Following its July sojourn near Earth crossing the northern skies from east to west, this celestial crystal now journeys out of view towards the dark outer solar system. With a narrow, elliptical orbit typical of comets, its rare visit to the inner solar system will not be repeated for a further 6,800 years.