Welcome to the May night sky. As darkness falls this month, the planets Mercury and Venus can be seen low on the western horizon, both in the constellation of Taurus.
Venus is by far the most brilliant object in this area and, through binoculars, its thin crescent form can be seen with its illuminated side facing the Sun. The planets Mars, Jupiter and Saturn now can only be seen after midnight in the constellations of Aquarius and Sagittarius, respectively.
The first week of May is the best time to catch sight of the Eta-Aquarids meteor shower. These can sometimes be very bright and originate from dust left over from the tail of comet Halley. Unfortunately, this year we have a full Moon at the end of the first week of May and this will hinder observations of this meteor shower, especially as this is a super full Moon being noticeably brighter than usual.
Earlier this year, interest was aroused by comet Atlas as it was following the orbit of the great comet of 1844 and it was hoped that comet Atlas would put on a similar spectacular show in May of this year. Unfortunately, as often is the case with comets, it broke up in April and faded from view.
Luckily, another potentially great comet was seen by the SOHO, Solar and Heliospheric Observatory – this project is a cooperative effort between the European Space Agency (ESA) and NASA – in March and recognised as a potentially bright object by astronomers in April.
Comets have a history of being rare and then suddenly two turn up together. This second object was called comet Swan after the science camera that caught the discovery image. Comet Swan has an orbital period of 25 million years and will pass close to the Earth on May 12 at a safe distance of 83 million kilometres.
In early May, you will have to get up just before sunrise and look over to the east-northeast horizon to have the first chance to see comet Swan from our part of the world. It will be at its brightest at around the middle of May in the constellation of Pisces. It will be best seen at around 5am local time.
To see the comet in the evening, the best time will be in late May when comet Swan will be close to the bright star Capella in the constellation of Auriga, seen over in the north-northwest sky as darkness falls.
The comet should have a thin blueish tail pointing away from the Sun and perhaps a shorter yellowish tail aligned with its orbital motion. As with all comets, it could break up and become faint and difficult to see. Only time will tell.
The Moon is full on the 7th, last quarter on the 14th, new on the 22nd and first quarter on May 30, 2020.
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Clive Jackson is the Director of the Camera Obscura (next to the Castle in Tavira), specialising in education and public outreach.
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