We’re heading into the warmer months again this time of year and looking forward to the brighter, warmer evenings, which may allow us to stargaze a little easier, if also a little later in the evening. There’s lots to look at this month, anyway, with a few meteor showers and even a lunar eclipse! The ISS flys over us more than a few times this month too – for times and locations, go to Spotthestation.nasa.gov.
We are treated to two meteor showers in the sky at this time of year; the Eta-Aquariids (also spelled Aquarids) and the Eta-Lyrids. The Aquariids take place throughout April and May, peaking on the 5th and 6th of May this year. The meteor shower is named as all are; from the constellation it appears to radiate from – in this case Aquarius. The constellation of Aquarius happens to be quite low in the sky in the early mornings at this time of year so it is maybe not the most easily seen meteor shower, although it peaks with around 50 meteors per hour.
The parent body of this meteor shower is probably the most famous comet – Halley. Halley is the cause of two meteor showers a year, these and the Orionids, which take place in October. Halley, like most comets, has a very elliptical orbit around the sun, but is a short period comet (with an orbit less than 200 years). Halley’s orbit is only 76 years long – in fact, it is the only naked-eye comet that can become visible from Earth twice in a human lifetime! The last time that Halley’s comet was visible was in 1986, and the next time it will be visible will be in 2061. On its trip around the sun, Halley trails behind it dust and debris it has gathered from the surrounding areas of space. It is this dust and debris that causes the meteor showers, when the earth passes through the orbit each year.
The Eta-Lyrids are the second meteor shower that takes place in May, though they are a minor shower. The whole meteor shower takes place in May, peaking on the 9th of May, just after the Eta-Aquariids. This is a short meteor shower compared to its contemporary, lasting just over a week. The constellation these meteors are named for is Lyra, a constellation that is high in the sky during the spring and summer months. In fact, Lyra contains a star, Vega, that belongs to the summer triangle – a prominent asterism with bright stars that can be seen during the warmer months. The comet that these meteors are associated with is a long-period comet burdened with the name C/1983 H1 IRAS-Araki-Alcock (after the satellite and two amateur astronomers who discovered it). The comet, which has an orbit of 970 years, was last seen in 1983 making the closest approach to earth of any comet in 200 years!
There are a number of lovely bright constellations that we can see on spring nights in the sky, including Leo the Lion. Leo, a zodiac constellation, can be easily spotted by looking for the asterism that makes up its head. The asterism (a pattern of stars which isn’t one of the official 88 constellations) is called The Sickle. It looks very much like a backwards question mark in the sky and makes up the front of the sphinx-like shape of the Leo constellation. In May, Leo can be seen in the West of the sky in the evenings.
The zodiac is a line of constellations that surrounds the Earth, and its name means band or belt of animals. The line is important to many cultures because of the events that take place there. The sun, moon and planets appear to move through this line of constellations in the sky throughout the year. If you are looking for any of these bodies this is the place to look! Because the sun, moon and planets always circle the Earth in front of the zodiac constellations, this is where eclipses and conjunctions appear in the sky as well!
Just under Leo though is another constellation which you will recognize as a sign of the Zodiac, although does not contain stars as bright as the ones in Leo. Cancer represents the crab, a medium sized constellation containing six stars, and was described by Ptolemy in the 2nd century AD. The constellation also contains two Messier objects, including M44 or NGC 2632, known as The Beehive Cluster. This is an open cluster of stars, and in fact is one of the biggest and closest open clusters to Earth. It was one of the first objects described using a telescope, by Galileo in 1609, who was able to spot 40 stars within the cluster. In actual fact there are over a thousand stars in the cluster, which were all formed from the same gas cloud and are all roughly the same age. Two planets were discovered in the cluster in 2012, each circling a different star. This was a significant discovery as they were the first planets orbiting a Sun-like star in a cluster. They are what is known as ‘Hot Jupiters’ – large gas giant planets that orbit very close to their star.
Early May sees Mercury visible in the northwest of the sky, close to the star cluster of the Pleiades in the evenings of the first week of the month. After Mercury comes within kissing distance of the Pleiades it bounces away. As Taurus moves down below the horizon, though, so does Mercury, becoming too low in the sky to see after the first week of May. Watch out though for the moon and Mercury to almost touch in the sky on the 1st and 2nd, before the moon flies off to pastures new higher in the sky later on in the week and month.
In a spectacular showing from the moon this month we are also treated to a total lunar eclipse in mid-May this year. A lunar eclipse is when the shadow of the Earth falls on the moon and paints it a deep red colour. This lunar eclipse in particular is a brief one, as the moon actually sets below the horizon during totality (the time where the entire surface of the moon is in shadow). Due to this, it might technically be more accurate to say that we are treated to half a total lunar eclipse! You’ll have to be an early riser to take in what we can see of the eclipse this month – the eclipse takes place in the early hours of the 16th of May. Look out for the start of the penumbral shadow passing over the moon at around 1:30am, with the umbral shadow being cast at 2:30am, and totality starting at 3:30am before the moon sets just after 4am. This whole show will be taking place low in the sky before the moon sets for the night.
The full moon this month takes place on the night of the 26th May and is known as the Flower moon. This name was given to the full moon of May because it heralds the blooming of so many flowers (in the Northern Hemisphere)! The moon this month will also be a supermoon, so the moon will appear slightly larger and brighter in the night sky. This supermoon is due to the orbit of the moon being slightly oval. The moon gets slightly closer to and further away from the earth as it goes around over the course of a month. Supermoons take place whenever the moon is at its closest approach to the Earth – the lunar perigee.
So, take some time out this month to do some moongazing, as well as looking out for a few meteors in the sky to wish on.