So here we are, heading into the summer holidays with thunderstorms all around us, but with some good news as the lockdown eases. Caravan parks are open again, and they make some of the best places to go stargazing, as they tend to be a bit more rural, and have less light pollution than our ordinary homes. So take a break from stressing about COVID and enjoy that summer sky.
One of the easiest things to spot in the summer night sky is the summer triangle. It is an asterism (shape in the sky that isn’t one of the official constellations) made up of three of the brightest stars in the summer sky, Altair, Deneb and Vega. Each of these stars are the brightest in their respective constellations. Altair belongs to the constellation of Aquila. Aquila represents an eagle, which belonged to the Roman God Jupiter, or the Greek god Zeus, depending on who you ask (they’re basically the same anyway – the Romans repurposed Greek gods for themselves) who carried his lightning bolts before he shot down unsuspecting humans for defying the Gods. Nice guy, Zeus. Aquila the eagle, at Zeus’s behest, also kidnapped a young boy called Ganymede. Zeus wanted a servant, and so Ganymede the shepherd boy became Zeus’ cup-bearer on Mount Olympus (represented in the constellation of Aquarius!).
The other two constellations whose brightest stars help make up the Summer triangle are Lyra and Cygnus. Cygnus is the graceful swan constellation which glides through the sky following its brightest star, Deneb. Deneb lies in the tail of the swan and it also marks the top of another easily spotted asterism, the northern cross (which may be in the south of the sky, but is so named as it is in the Northern hemisphere, and to differentiate it from the Southern cross, in the Southern Hemisphere). Deneb is a blue-white supergiant star, and astronomers have predicted that it will become our pole star in a few thousand years as the Earth wobbles on its axis.
Vega belongs to the constellation of Lyra, the lyre. Funnily enough, given its proximity to Aquila, this constellation used to be depicted by an eagle carrying a lyre, and is still sometimes called Aquila Cadens, or ‘Falling Eagle’ (and sometimes even falling vulture). More traditionally, though, it represents the first lyre ever made, presented to Apollo by Hermes, who made it out of a tortoise shell, and later owned by Orpheus who used its beautiful music to charm all who heard it, even Hades, when he went to save his true love Eurydice from the underworld. I’ll leave that story there and we can all pretend it ended nicely (it didn’t).
Aquila and Cygnus both lie along the plane of the Milky Way, meaning that it contains a large number of stars and deep-sky objects. There are three planetary Nebulae within the borders of this constellation, NGC 6804, 6781 and 6751. Planetary nebulae appear as colourful rings in the sky, and confusingly, they have nothing to do with planets. In reality, planetary nebulae are a stage in the life cycle of stars, towards the end of their life. Once a star has run out of hydrogen to burn at its core, it swells up and becomes a Red Giant, a larger but cooler type of star. After this, the star puffs off its outer layers, shrinks back down to around the size of the earth and becomes a white dwarf. The puffed off outer layers become the colourful ring of gases around the planetary nebula, and the tiny white dwarf star is at the centre (look carefully, it’s a tiny white dot at the centre of the ring!).
The Milky Way is in the perfect position during the summer to be seen in the southern sky. Just above the horizon, in the middle of the night at the height of summer we can see the central bulge of the galaxy (Sagittarius’ arrow points right to it). However, you will have to be in a very rural and dark area (or in the southern Hemisphere) and will still only be able to see it faintly. It is many stargazers’ goal to head to the Southern hemisphere to see it in all its glory! Look out carefully and you might be able to catch a glimpse this summer!
Near the start of the month this year is the full moon. On the 5th of July we will see the Buck moon, also known as the thunder moon, hay moon and wort moon. These names were given to each full moon of the year to help track the changing seasons, and are a mixture of Native American, Anglo-Saxon and Germanic names. The July full moon is named the buck moon after the male deer whose horns start to grow at this time of year. It is also named after the frequent thunderstorms in the summer, and the hay harvest which takes place now. The final name, the wort moon, is also due to it being a time to harvest, but this time fresh herbs (‘worts’) to use in food and medicine.
At the opposite end of the moon cycle is the new moon, which takes place this month on the 20th of July. But another exciting event takes place on this day; the planet Saturn will be at opposition. This means that it is at full brightness in the sky, lit entirely by the sun as it comes to its closest approach to Earth. If you have a decently sized telescope you will be able to see Saturn, its rings and even some of its many moons, as it will be brighter than any other time of year!
The end of July will be a busy celestial time this month, as there are a number of events taking place in the sky within a few weeks. Two days after Saturn is at opposition, Mercury takes the stage as it comes to its Greatest Western Elongation. This means that it will reach its highest point above the horizon (but still be quite low) in the eastern sky during the summer mornings, just before sunrise.
There is even a meteor shower this month, appearing to originate from the constellation of Aquarius, called the Delta Aquarids. This shower takes place over a long time, from the 12th of July to the 23rd of August, but it peaks on the night of the 28th and morning of 29th of July, with up to 20 meteors visible in an hour. The peak night will not be the most favourable to see some of the fainter meteors as there will be a relatively bright half-moon, but you never know. Get to somewhere dark and you might be lucky!
So have a night out on one of the long boring days while we’re isolating and have some fun looking out for stars. Less light pollution at night during lockdown, as well as less air pollution has us seeing more stars than before, and makes our night sky looks absolutely dazzling.