Welcome to the May night sky. The night of May 4 sees the Eta Aquarid meteor shower. This is one of the best showers visible at this time of the year.
The meteors that will appear across the night sky are small particles of dust left over from the tail of Halley’s Comet, and this shower has been observed every year since 401AD. So, it is one of the oldest known meteor showers.
Also on the 4th we happen to have a New Moon, so the sky should be dark to help in seeing any faint meteors.
Having said that, the Eta Aquarids can sometimes be exceptionally bright and leave behind in the night sky a luminous “smoke” trail that may persist for several minutes.
The red planet Mars can only be seen now for a short while over on the western horizon. So we have no bright planets easily visible in the May evening sky.
After midnight, over in the southeast, the gas giant planet Jupiter will rise in the constellation of Ophiuchus and, two hours later, the ringed planet Saturn will also rise in the southeast. Saturn is in the constellation of Sagittarius, and this means that when seen from high latitudes in the northern hemisphere, it would be low to the southern horizon and the Earth’s atmosphere will dim the view somewhat.
But, with any small telescope, it would be possible to see Saturn’s largest moon, called Titan. This moon is larger than planet Mercury and it has a thick nitrogen atmosphere. This atmosphere is denser than the Earth’s, so an astronaut could walk on the surface of Titan without a pressurised space suit. Although due to the absence of oxygen in Titan’s atmosphere, some sort of breathing apparatus would be required. Also, the severe cold at 160 degrees below zero would be a problem.
Saturn has more than 60 known moons and one of them, called Enceladus, is exceptional. This 500km diameter object is quite small in comparison with Titan and orbits very close to the outer edge of Saturn’s rings. This moon is covered in fresh water, ice and snow, and has an active water geyser at its south pole. This indicates an internal heat source possibly creating a salty sub-surface ocean that could be home for primitive microbial life.
The Moon is new on the 4th, first quarter on the 12th, full on the 18th and last quarter on May 26.
By Clive Jackson
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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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To see the April Sky Map click on the pdf link below