What’s In The Sky: Summer

Summer is a great time to enjoy the long warm evenings, and what better to extend them than with a little stargazing?

While stargazing in the summer takes place a little later than usual, the nights are warm and the skies are usually clear making it a very pleasant experience. And the summer sky is packed full of constellations, planets, and deep sky objects.

Here are a few of our favourites:

Hercules the Hero

Hercules is a well-known mythological hero and a fantastic constellation to view in the summer sky.

The ancient Greeks used a trapezoid pattern of stars to represent one of their greatest heroes, known to them as Herakles. Hercules is the Roman version of his name. Hercules features in many stories from the creation of the Milky Way when he was a baby to his famous ‘Twelve Labours’. We can see some of the characters in these labours in the night sky near Hercules, such as the constellations of Leo and Hydra. And of course, there’s the starry band of the Milky Way itself.

Hercules isn’t the easiest constellation to spot as its stars aren’t the brightest and they’re quite spread out in the sky. However, with a little practice it can be found.

At this time of the year it can be found just after sunset due south. The easiest way to locate it is to look for the bright star Vega (just west of the Milky Way). Hercules lies just to the west of Vega. Look for a small square of stars which represents Hercules’ torso. His limbs branch out from there.

Being a large constellation, Hercules contains a few deep sky objects that can be found with a good set of binoculars or a telescope. One of the most visually stunning of these is the Hercules Globular Cluster, or M13. This is a collection of several hundred thousand stars. These stars are packed into a region a hundred times denser than the area around our Solar System.

In 1974 we beamed a message towards this cluster as an experiment in contacting extraterrestrial life. However, the round trip for our signal to get there and to receive a response is around 50,000 years, so don’t wait by the voicemail machine!

Aquila the Eagle

In the summer if we look towards the south-east we can see the constellation Aquila. Originally described by the astronomer Ptolomy, this constellation sits close to the Milky Way and lies on the celestial equator (the plane of the sky that lines up with the Earth’s equator).

Aquila was described by Ptolomy as an eagle. In Greek mythology Aquila is often described as the bird that would hold Zeus’ thunderbolts. It was often said that the thunder was caused by the beating of the bird’s great wings as it chased the thunderbolts across the sky.

The ancient Chinese told a different story. They would talk of Niu Lang, a farmer who fell in love with the fairy princess Zhi Nu (represented by the star Vega). Niu Lang and his two children were separated from the princess by the fairy queen, who scarred the sky to keep them apart (the Milky Way). These three characters are represented by the brighter stars of Aquila.

Being close to the Milky Way, there are a few deep sky objects than can be found within the Aquila constellation. One of the prettiest is the Glowing Eye nebula (NGC 6751). This object is a planetary nebula. These types of nebula form when stars like our own Sun reach the end of their life. As these stars stop fusing hydrogen they begin to fuse other materials like helium and lithium. This causes instabilities in the star that can cause material to escape into the surrounding environment. As this material blossoms out into space, it creates intricate glowing patterns known as planetary nebula.

Saturn at Opposition

Constellations are not the only thing that can be seen in the summer night sky. This year during the first half of summer we are treated to a great view of Saturn. Of all the planets, Saturn is one of the best to observe thanks to its distinctive rings. Even with a small set of binoculars, you can make out its oval shape similar to what Galileo saw back in the 17th century. With a small telescope you can make out the rings and even some of Saturn’s moons.

In late June this year, Saturn is at opposition. This means that it is directly opposite the Sun (from Earth’s perspective) and at its closest point to the Earth, making it the brightest that it will be all year. Currently Saturn’s rings are tilted towards the Earth making it easier to see their pattern.

During these warm summer months, we encourage you to take the opportunity to do a little stargazing. Remember that while specialist equipment like binoculars and telescopes can help, they are not necessary. Most of the objects we’ve talked about can be seen with just your eyes. Some objects will require a little more assistance. A good place to start is a good pair of binoculars or a small telescope, if you have access to one. If you don’t local astronomy and star gazing groups can be a great place to get involved in the hobby.

However, if you would like a little extra help, why not pick up a ‘What’s in the Sky’ stargazing guide or pop along to one of our ‘Tour of the Night Sky’ planetarium shows the next time you visit the National Space Centre.

You’ll be an expert in no time!