5 Astronomical Highlights This Summer
There are some great astronomical sights to look out for during the summer nights as the days get longer and warmer.
The Summer Triangle
The Summer Triangle is an asterism of three stars – Deneb, Vega, and Altair. An asterism is a familiar star pattern – either a small but easily recognisable part of a constellation or as in the case of the Summer Triangle, a star pattern made up of bright stars taken from several different constellations. Each star Deneb, Vega, and Altair is found in a separate constellation – Cygnus the Swan, Lyra the Harp, and Aquila the Eagle, respectively.
The Summer Triangle is one of the largest asterisms and is easy to spot due to the stars being very bright. Throughout the summer months it can be found in the south around midnight. The brightest star you will spot in the Summer Triangle is Vega, which is also the second brightest star in the northern hemisphere (the first being Arcturus).
The most exciting part about the Summer Triangle is what you find inside it. The arm of the Milky Way goes straight through the Summer Triangle. It may look like a cloud, but it is in fact the obscuring gas and dust cloaking the billions of stars in our galaxy. The constellation Cygnus is a swan, so it appears to be swimming along the Milky Way! However, the Milky Way can only be seen with minimal light pollution. To find your nearest dark sky site using Go Stargazing.
Cygnus is also known as the Northern Cross and is home to a black hole – Cygnus X-1. This black hole emits X-rays and was the first galactic X-ray source accepted as a black hole.
A Supermoon is when the full moon or new moon occurs near the Moon’s closest approach to Earth (its perigee). It appears 14 percent bigger, and 30 percent brighter compared to its apogee (when the Moon is furthest away from the Earth). This influences the tides but only by a few inches compared to a normal lunar cycle.
There are two Supermoons this year; the Strawberry Moon on 14 June and the Buck Moon on 13 July. Each full moon has a specific name, based on the time of the year. For example, the Strawberry Moon is when strawberries start to ripen, and the Buck Moon is when male deer’s antlers are in full growth. If you would like to know more about the full moon, check out our Full Moon and Full Facts blog.
Since April, the planets Mercury, Venus, Mars, Jupiter, and Saturn have been lining up in the night sky. By 24 June, the five planets and the Moon will align from the Earth’s perspective from east to south. This is a rare event so will be a fantastic photo opportunity. The best time to view this is just before sunrise. Uranus and Neptune are also in this alignment; however you won’t be able to see them with the naked eye. You’ll need a telescope to spot these ice giant planets. It is important to point out that the planets are not actually aligned in the Solar System, they just appear aligned in the sky.
Perseids Meteor Shower
The Perseids Meteor Shower is probably the most exciting event of the summer. The peak is 12-13 August, and this event occurs every summer with up to 100 meteors per hour. This happens every year due to the Earth passing through the remnants of the comet Swift-Tuttle. The Perseids are named after the constellation Perseus as this is where the meteors seem to radiate from.
The best way to view the meteor shower is by going to a very dark area with minimal light pollution, allow your eyes to adjust to the darkness and enjoy the shooting stars!
Saturn in Opposition
Saturn will reach opposition on 14 August, rising in the southeast around sunset in the constellation of Capricornus, and will be visible all night. When a planet is at opposition, the Solar System is aligned so that the planet in question lies on the same side of the Sun as the Earth, so is fully illuminated. At this time Saturn will also make its closest approach to Earth, making it appear its largest and brightest. Its highest point in the sky will be around 1:00am and is best to view with a telescope to be able to see the rings.
Saturn is the second largest planet in the Solar System, after Jupiter. Its rings are mostly made of ice particles, rocky debris, and dust. It has the greatest number of moons in the Solar System, currently standing at 82. One of Saturn’s moons Titan, has an atmosphere and is larger than Mercury.
About the author: Lucy Spencer is a Space Communications Presenter at the National Space Centre.