The Evening Sky in March 2025
Jupiter is the ‘evening star’, appearing in the northwest at early twilight. It sets after midnight at the beginning of the month and before 11 pm at the end. The Moon will be near Jupiter on the 6th. Orange Mars is due north at dusk, low in the sky. It is fading as we leave it behind. The Moon will be near Mars on the 8th and 9th. At the beginning of the month brilliant Venus (not on the chart) sets due west half an hour after the Sun. The very thin crescent Moon will be above Venus on the 2nd. Venus sinks into the twilight before passing between us and the Sun on the 23rd.
Northwest of overhead is Sirius. It is the brightest true star in the sky. Southwest of the zenith is Canopus, the second brightest star. Below and left of Sirius are bluish Rigel and orange Betelgeuse, the brightest stars in Orion. Between them is a line of three stars: Orion's belt. To southern hemisphere star watchers, the line of stars makes the bottom of 'The Pot'. Above and left of Jupiter is orange Aldebaran. It is at one tip of an upside-down V. The V is the face of Taurus the bull with Aldebaran being one of his eyes. Well left of Jupiter, and lower, is the Pleiades or Matariki star cluster. It sets after 10 pm, mid-month. The cluster is about 440 light-years* away.
Sirius is the brightest star both because it is relatively close, nine light-years away, and 23 times brighter than the sun. Rigel is a bluish supergiant star, 40 000 times brighter than the sun and much hotter. It is 800 light-years away. Orange Betelgeuse is a red-giant star, cooler than the sun but much bigger and 9000 times brighter. Betelgeuse is 400 light-years from us.
The handle of "The Pot", or Orion's sword, has the Orion Nebula at its centre; a glowing gas cloud many light-years across and 1300 light years away. It is a place where dust and gas in space are gathering together to make new stars. Some of the stars are much bigger and hotter than the Sun. Ultra-violet light from them causes the left-over gas to glow, lighting up the nebula. It is easily seen in binoculars.
Below and right of Mars are Pollux and Castor marking the heads of Gemini the twins. Though paired in mythology, the two stars are not related at all. Castor is a hot white star like Sirius but 52 light years away. Golden Pollux is bigger and brighter but cooler than Sirius and 34 light-years away. Above and right of them is the Praesepe star cluster, marking the shell of Cancer the crab. Praesepe is also called the Beehive cluster, the reason obvious when it is viewed in binoculars. It is some 500 light-years from us.
Crux, the Southern Cross, is in the southeast. Below it are Beta and Alpha Centauri, often called 'The Pointers'. Alpha Centauri is the closest naked-eye star, 4.3 light years away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of light-years away. Canopus is also a very luminous distant star; 13 000 times brighter than the sun and 300 light-years away.
The Milky Way is brightest in the southeast toward Crux. It becomes broader lower in the southeast toward Scorpius. Above Crux the Milky Way can be traced to nearly overhead where it fades. It becomes very faint in the north, right of Orion where we are looking toward the Galaxy's nearby edge. The centre of the Galaxy is in the broad part of the Milky Way below Scorpius in the southeast.
The Clouds of Magellan, LMC and SMC are high in the south sky. They are easily seen by eye on a dark moonless night, looking like misty patches. They are two small galaxies about 160 000 and 200 000 light years away. The Large Cloud is around a quarter the mass of the Milky Way.
The full Moon will rise totally eclipsed on the 14th. Being exactly opposite the Sun, the Moon rises at sunset. It starts to exit the dark inner part of Earth’s shadow, the umbra, at 8:31 and is fully out by 9:48. It will still look a little odd till it leaves the fuzzy edge of the shadow, the penumbra, at 11:00. It has become fashionable to call the totally eclipsed Moon a ‘blood Moon’, but its colour can be anything from orange brown like a dried apricot to deep bronze. It all depends on how much cloud there is around the rim of the Earth as seen from the Moon.
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 sunlight four years to reach the nearest star, Alpha Centauri.
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