Our monthly guide for stargazers
◼ Jupiter and Saturn were both at opposition last month and so are visible as soon as darkness falls. Venus is shining brilliantly before dawn. Mars is prominent in the morning sky. And Comet NEOWISE is fading but still easy to spot in binoculars. August also sees the peak of the Perseid meteor shower. Here’s more about the planets, stars and other objects you can see in the night sky in August 2020.
August’s star chart
Click on the image above for an interactive map of constellations visible in the sky. It can be adjusted for any time and date.
(We also have a map of the night sky in the southern hemisphere.)
The stars in August
As the sky grows dark at northern latitudes in August, the famous Summer Triangle is already high in the eastern sky. This is a large asterism rather than a constellation, and is formed of three stars, Vega, Deneb and Altair, which are the brightest stars in the constellations of Lyra, Cygnus and Aquila, respectively. Due south, and to the right of Vega, see the figure of one of the sky’s heroes, Hercules.
On the other side of Hercules, the constellation of Bootes, the Herdsman, includes another of the sky’s brightest stars, Arcturus. A good way to find Arcturus is to follow the curved “handle” of the Big Dipper, or Plough, which is the familiar asterism in Ursa Major. Ursa Major is sinking in the evening sky on August evenings while W-shaped Cassiopeia, on the opposite side of the Pole Star, is rising in the east. Between Hercules and Arcturus, you can see a little circlet of stars called Corona Borealis, the Northern Crown.
In the Southern Hemisphere, Crux, the Southern Cross, is still high, above the south celestial pole, followed by the bright stars Alpha and Beta Centauri.
The planets in August 2020
Mercury, the innermost planet in the Solar System, is in the morning sky but heading back very swiftly towards the Sun as August opens. Northern hemisphere observers might be able to glimpse it over the first couple of mornings in the month, low in the north-east before dawn twilight becomes too bright, but a clear, unobstructed horizon will be essential. Read more about Mercury.
Venus is a brilliant beacon in the morning sky now, shining at -4.4 magnitude. It rises in the north-east more than three hours before the Sun at the start of August. The planet is shrinking in diameter as it recedes from the Earth, but its phase is growing to resemble a half moon. The Moon will lie close to the planet in the sky on the 15th and 16th.
Mars is steadily increasing in brightness as its orbit carries it closer to the Earth, and its magnitude increases from -1.1 to -1.8 over the course of the month. It rises a little after 10pm local time at the start of August and about an hour and a half earlier by the end. It no longer looks like a bright star, but more like a bright planet, and you will be able to detect its orangey hue. Read our guide to Mars.
Giant planet Jupiter reached opposition on 14 July, and so rises before nightfall, and it is visible for much of the night. It is another planet that is currently on a southerly part of the ecliptic, in the constellation of Sagittarius, the view is much better from southern latitudes, such as Australia, New Zealand, South Africa, or South America, where Jupiter will be high in the sky.
It is now shining brightly at around magnitude -2.7, so is easy to spot, despite being low in Sagittarius for observers in the northern hemisphere. As with Mars and Saturn, the view is much better from southern latitudes, such as Australia, New Zealand, South Africa, or South America, where Jupiter will be high in the sky.
Even a small telescope will reveal the cloud belts on Jupiter and its four main moons, the Galilean satellites Io, Europa, Ganymede and Callisto. The planet Saturn lies a little to the east of Jupiter. The Full Moon will be close by on the night of the 29th. Read more about planet Jupiter.
The ringed planet, another gas giant, reached opposition on 20 July, so is also visible all evening and for much of the night. Saturn shines at around magnitude 0.4, like one of the brightest stars, and with a yellowish light. Sadly again for northern hemisphere observers, Saturn is low in the sky, lying not far from Jupiter, in the constellation of Sagittarius. From the southern hemisphere, Saturn will rise high in the sky, and so this will be an ideal time to observe it. Read more about Saturn.
Uranus lies in the constellation of Aries, rising in the late evening at the start of August. In a dark sky, this planet is theoretically visible with the unaided eye, shining at a dim magnitude 5.8. However, at northern latitudes where summer twilight still hangs around for much of the night, you will definitely need binoculars to see it this month. Read more about Uranus.
The outer ice giant is a couple of magnitudes fainter than its twin, Uranus, and shines at magnitude 7.8 this month. You will be able to glimpse it with binoculars, or a small telescope, in the constellation of Aquarius. It rises at around 10pm at the start of August and a couple of hours earlier by the end of the month. Read more about Neptune.
Comet NEOWISE fades
Comet NEOWISE put on a splendid show for observers in the northern hemisphere during July. It reached first magnitude as it emerged into the morning twilight, then developed two fine tails, of gas and dust, as it continued to approach the Earth. The comet, whose full name is C/2020 F3 (NEOWISE) is now fading as it heads south, through Coma Berenices and Virgo, but should be visible with binoculars for a while yet. Our chart will help you find it.
Related: Your guide to comets
Meteor showers in August
Three meteor showers are active in August. The best known its the Perseids, which reaches its maximum on the night of the 11th/12th and 12th/13th August. The Moon will be at Last Quarter phase on the 11th, so the best nights to observe are likely to be after maximum, as moonlight becomes less of a problem. The meteors are debris from Comet 109P/Swift-Tuttle. Read our guide to viewing the Perseids in 2020.
A reliable shower that favours Southern Hemisphere observers is the Delta Aquariids which are active from July 12 to August 23. At their peak, under ideal conditions, the rates for a single observer reach 16 an hour. They are mainly faint meteors, and the Moon will be just past First Quarter on the night of maximum, July 28-29, and so moonlight will interfere. Parent comet of this shower is believed to be 96P/Machholz.
The third shower is the Alpha Capricornids, which are active from July 3 to August 15, according to the International Meteor Organization. Though activity is low, with a peak rate of only five meteors or so an hour for a few nights, the shower delivers a number of bright fireballs. This shower’s broad maximum is also centred on the night of July 28-29, with the Moon just past First Quarter.
Related: A simple guide to observing meteors
Related: How to photograph a meteor shower
Full Moon: Aug 3
Last Quarter: Aug 11
New Moon: Aug 19
First Quarter: Aug 25
The Moon always makes a great target for a small telescope, which come into view as its phases change. We’ve a guide to where to find 50 of the best lunar features, plus a checklist to download so you can tick them off as you spot them! Don’t have a telescope? Here’s our guide to choosing one.
Fifty fantastic features – our amazing Moon
Here’s our guide to observing some of the finest sights on the Moon with small telescopes. Click here for pages of charts that will help you find interesting features to seek out yourself, including craters, lava flows, mountain ranges and deep chasms!
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