What’s in the sky in July?

Throughout July our days will finally begin to shorten, and we will get slightly more time to view our lovely Irish night skies. We have made it past the Summer Solstice and at the beginning of July we will see sunset just before 10pm and sunrise at 5am. By the end of the month sunset will be at 9.30pm and sunrise just before 6am. Ireland’s summer weather will hopefully afford us many clear nights throughout July, perfect for some evening stargazing. However, the nights are still very short and the astronomical twilight we have seen throughout June will persist for the beginning of the month.

Astronomical Twilight

During the summer months, Ireland experiences very short or even non-existent periods of true darkness due to its high latitude (approximately 53 degrees north) and the tilt of the Earth. Around the summer solstice in late June/early July, the Sun does not dip more than 18 degrees below the horizon at night, which means there is continuous astronomical twilight at night. During this time, we may not be able to see some of the very faint objects in our sky as the sun slightly illuminates the sky from below. However, there are many interesting things for us to observe and look out for.

Planets

This month our planets will start returning to our skies in force with Saturn, Mars and Jupiter all easily visible in the early hours of the morning from the start of the month. Our planets follow the same path as the Sun through the sky so look east, south, or west to find them. The planets are quite distinctive compared to stars because they do not twinkle. This is because stars are very far away and the light from a star is coming from a tiny source that human eyes aren’t strong enough to fully make out. Atmospheric turbulence as the light passes through our atmosphere will give the illusion of a star twinkling. Planets do not share this phenomenon because they are much closer to us and therefore appear larger in our sky, so the light reflected off a planet will appear static and unchanging.

Saturn:

At the beginning of July, look to the east around 1am to find Saturn rising. It should be easy to spot, being the brightest object in that part of the sky. By the end of the month, it will rise around 11pm.

Mars:

Mars will rise in the east just before 3am at the beginning of July. Mars should look slightly red, due to iron oxide on its surface. Mars’s thin atmosphere is often filled with this iron oxide dust from storms on the planet’s surface which enhances its reddish appearance. By the end of the month, Mars will rise around 1.30am.

Jupiter:

At the start of July, Jupiter will rise in the east at about 3.30am, not long before sunrise. Jupiter is one of the brightest objects in our night sky due to its size. Being the largest planet in the solar system, Jupiter can reflect much more of the Sun’s light and look even brighter than some of the planets nearer to us, like Mars. The only things that will be brighter than Jupiter are Venus and the Moon. By the end of July, Jupiter will be in our sky from 2pm.

Venus and Mercury:

Venus and Mercury will be possible to spot this month, but not easily. They are both close to the Sun, and we will see them just after sunset for a brief time in the evening. Look to the west to find them in the Sun’s glow. Venus will become more prominent as the month progresses whereas Mercury will leave our sky about halfway through July. They are both only visible for short periods of time and will be very low to the horizon, so make sure there are no trees or buildings in your way. Venus is often known by two nicknames, ‘The Evening Star’ or ‘The Morning Star’. This is because Venus is the brightest object we can see from Earth at night (excluding the Moon) and the closest planet to us. Venus and Mercury are also both closer to the Sun than we are, so from our perspective we never see them far from where the Sun is. This is why we only see them for short periods of time around sunrise or sunset.

Uranus:

Uranus will be up in the morning too, but you may need some binoculars to spot this blue planet depending on where you live. Uranus can be seen by the naked eye, but only in areas with very dark skies. To find Uranus, look first for Jupiter or Mars. At the beginning of July, it will be directly between them and as the month continues, it will pass by Mars in a planetary conjunction on July 15th.

Moon

The moon’s phases can provide different viewing experiences, from a new moon, which is ideal for stargazing, to a full moon, which can wash out faint objects but is a beautiful sight. We will have a new moon on July 5th and our next full moon on July 21st. The July full moon is sometimes known as the Buck Moon, which comes from this being the time of year when male deer’s antlers grow.

Milky Way

The Milky Way is a remarkable sight, especially during the warmer summer months. It will appear as a glowing, milky band across the sky. The most stunning part of the Milky Way to observe is the galaxy’s centre, located in the constellation Sagittarius, which is visible in the southern sky. The supermassive black hole at the Milky Way’s core is known as Sagittarius A* because it is located within the constellation Sagittarius. It will rise around midnight and move westward throughout the night. For the best viewing experience, choose a dark location far from city or town lights, such as the Kerry International Dark Sky Reserve or the Mayo Dark Sky Park. If these are not on your doorstep, just head out into the countryside anywhere the sky is dark. The best time to view the Milky Way is during the new moon or when the moon is below the horizon. Make sure you give your eyes time to adjust to the dark and avoid looking at your phone.

Cassiopeia

If you do not want to stay up late to spot our bright planets Saturn, Jupiter, or Mars, we still have all our stars to explore. Let’s focus on the constellation Cassiopeia in our Northern sky. Cassiopeia is easily recognisable by its distinctive “W” shape formed by five bright stars. Look northeast to find her throughout July. In Greek mythology, Cassiopeia was the queen of Aethiopia, married to King Cepheus, and mother to Princess Andromeda. She was known for her stunning beauty but also her vanity and arrogance. As a punishment for her vanity, Cassiopeia was placed in the sky as a constellation, forever sitting in a chair, sometimes appearing upside down, as a reminder of her pride. Located near the north celestial pole, Cassiopeia is a circumpolar constellation for observers in Ireland, meaning it never fully sets below the horizon and we see it all year long. It serves as a useful marker for locating the Andromeda Galaxy, which lies nearby in the sky.

Andromeda Galaxy (M31)

The Andromeda Galaxy (M31) is the closest spiral galaxy to the Milky Way and the largest galaxy in the Local Group. It is about 2.5 million light-years from Earth. To the naked eye, the Andromeda Galaxy appears as a faint smudge of light, but you will need a dark sky to see this so try to aim for a moonless night. Through binoculars or a telescope, it reveals more detail, including its bright core and spiral arms. The galaxy spans about 220,000 light-years in diameter and contains one trillion stars, more than twice the number in the Milky Way. Andromeda is on a collision course with the Milky Way. In about 4.5 billion years, the two galaxies are expected to merge, forming a new, larger galaxy often referred to as “Milkdromeda”. By using Cassiopeia as a guide, you can easily locate the Andromeda Galaxy and enjoy one of the most spectacular objects in the night sky. First, look for the W-shape of Cassiopeia in the north. Next, locate the star Schedar, the brightest star in Cassiopeia. Picture Scheder as the point of an arrow and follow it across to find Andromeda (see picture).

July has exciting skies in store for us with the return of the planets, the Milky Way’s prominence and countless stars to observe. If you capture any images, make sure you tag us on social media or email us. Happy stargazing!