In February 1998, a four-day conference was held in Tenerife, Spain, dedicated to Hale-Bopp and the scientific findings obtained globally. Due to the length of time the comet was visible, its orbit and size, Hale-Bopp could be examined and studied for a very long time. Credit: Alan Hale What did we learn from Hale-Bopp?Ĭomets and other small icy bodies can hold clues to origins of life and our Solar System. Hale-Bopp had a huge nucleus approximately 40-60 kilometres wide and had two beautiful prominent tails.Ī third, very faint sodium tail was also observed using specialised instruments, which made Hale-Bopp unique.Īlan Hale (right) and Thomas Bopp meet at a star party in Socorro, New Mexico, 1996. It eventually moved into the southern hemisphere, with the last reported naked-eye sighting in December 1997. Its size and orbital period explains why we saw it in our skies for such an unprecedented length of time. Hale-Bopp shone bright at magnitude -1, the equivalent of the star Sirius in the constellation Canis Major, and became known as the Great Comet of 1997. The comet reached perihelion, its closest approach to the Sun (0.9 AU), on 1 April 1997. I figured that, at best, it might be a newly found short-period comet' It was near the ecliptic and retrograding slowly.

I had no way of knowing at the time that it would turn out to be such a bright object. Little did Hale know that he, alongside Thomas Bopp who was observing in neighbouring Arizona, had just discovered one of the most important comets of the century.įollowing their observations, they both reported their findings and the comet’s discovery was officially announced by the International Astronomical Union on 23 July 1995.ĭue to the comet’s magnitude at the time of discovery and being at a distance of 7.2 astronomical units, or AU (1 AU being the average distance between the Sun and Earth), Hale was unaware of how bright the comet would become. When I turned the telescope to the globular star cluster M70 in Sagittarius I noticed a dimmer, fuzzy object in the same field of view.' 'I was passing the time waiting for 6P/d’Arrest to appear over the horizon by looking at deep-sky objects. 'I was using a 41-centimetre Meade Newtonian reflector that I had purchased second-hand a few years earlier,' he tells us.

On a clear night in July 1995, Alan Hale was observing comets 71P/Clark and 6P/d’Arrest from his home in Cloudcroft, New Mexico when he made the discovery. Credit: Linda Davison Discovering Hale-Bopp Its orbital period is huge, taking approximately 2,533 years to orbit the Sun.Ĭomet Hale-Bopp photographer by Linda Davison from the Lake District, 29 March 1997. Hale-Bopp is a long period comet and we will not see it again in our lifetime. Originating from beyond Neptune in the Oort cloud, their elliptical orbits are long and they can take around 200 years, or even thousands, to orbit the Sun. Long period comets are comets that we do not see for a very long time. We last saw the comet in 1986 and expect to see it again in 2061. Halley’s comet (1P/Halley) is famous amongst astronomers as a short period comet, and some of us may be lucky enough to see it ‘twice in a lifetime’. Located between Neptune and Pluto, comets starting their journey from here can make one orbit of the Sun in less than 200 years. Originating from the Kuiper Belt, short period comets are relatively close to Earth. We don’t see bright comets all that often - at least not ones observable to the naked eye - but fainter comets are quite common, and a number are discovered each year. These can be hundreds of kilometres long. The nucleus starts to evaporate, creating a coma, and tails of gases and dust formed by the solar wind start to appear. Comets come from two areas in space: the Kuiper Belt and the Oort cloud.Ĭomposed of ice and rock, they become visible when they approach the Sun and warm up.

Hale bopp comet