The Evening Sky in August 2025
Bright stars are widely scattered over the sky. Vega on the north skyline is balanced by Canopus low in the south. Canopus twinkles with all colours as its white light is broken up by the air. So does Vega but, being fainter, it's not so obvious. Orange Arcturus is in the northwest, twinkling red and green as it sets. Canopus is the second brightest true star. (Sirius, the brightest star, is in the morning sky.) Arcturus is the fourth-brightest star in the sky and the brightest north of the equator. Vega is the fifth brightest of all the stars and the second brightest north of the equator.
North of the zenith is orange Antares, marking the body of Scorpius. The Scorpion's tail hooks around the zenith like a back-to-front question mark. Antares and the tail make the 'fish-hook of Maui' in Māori star lore. Antares is a red giant star: 600 light-years* away and 19 000 times brighter than the sun. Below or right of the Scorpion's tail is 'the teapot' made by the brightest stars of Sagittarius. It is upside down in our southern hemisphere view.
Midway down the southwest sky 'The Pointers ', Beta and Alpha Centauri, point down and rightward to Crux the Southern Cross. Alpha Centauri is the third brightest star in the sky (planets not counted) and the closest of the naked-eye stars, 4.3 light-years away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light years away and thousands of times brighter than the sun.
The Milky Way is brightest and broadest overhead in Scorpius and Sagittarius. In a dark sky it can be traced down past the Pointers and Crux into the southwest. To the northeast it passes Altair, meeting the skyline right of Vega. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. The thick hub of the galaxy, 27,000 light years away, is in Sagittarius. The actual centre is hidden by dust clouds in space. The nearer dust clouds appear as gaps and slots in the Milky Way. Binoculars show many clusters of stars and some glowing gas clouds in the Milky Way. The Large and Small Clouds of Magellan LMC and SMC look like two misty patches of light low in the south, easily seen by eye on a dark moonless night. They are galaxies like our Milky Way but much smaller. The LMC is about 160 000 light years away; the SMC about 200 000 light years away.
Mars is the only planet in the early evening sky. It looks like a medium-bright orange-red star low in the west. It sets soon after 9 p.m. mid-month. It is 330 million km away, so appears tiny in a telescope. The Moon will be near Mars on the 26th.
Saturn rises due east around 9:40 at the beginning of the month and around 7:30 at the end. It looks like a medium-bright star with a cream tint, all on its own. It is likely to be fuzzy in a telescope when low in the sky. The ring is nearly edge-on to us so looks like a line on each side of the planet. The shadow of the ring makes a dark line across Saturn. Saturn’s larger moons orbit in the same plane as the rings so their shadows also cross the planet. On August 3rd, the shadow of Titan, Saturn’s biggest moon, will be on the planet when it rises. The shadow moves off just after 11 pm. On the 18th Titan’s shadow will again be on Saturn when it rises and will move off at 10 pm. The near-full Moon will be beside Saturn on the night of the 12th-13th.
Venus is the ‘morning star’, rising in the northeast soon after 5 a.m. at the beginning of the month and around 5:20 at the end. It is joined by Jupiter. At the beginning of the month Jupiter appears below and right of Venus, rising before 6 a.m. It rises four minutes earlier each day as it moves up the sky toward Venus. On the 12th and 13th the two planets will be a degree (two full moon widths) apart, making an eye-catching pair. Venus is the brilliant silver ‘star’. Jupiter is a bit fainter and has a golden tint. Jupiter continues to move up the sky, rising around 4:20 at the end of August. The Moon will be near the two planets on the 20th and 21st.
*A light year (l.y.) is the distance that light travels in one year: nearly 10 million million km or 10^13 km. Sunlight takes eight minutes to get here; moonlight about one second. Sunlight reaches Neptune, the outermost major planet, in four hours. It takes four years for sunlight to reach the nearest star, Alpha Centauri.
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