The night sky in March 202
We now notice the lengthening of the day as we head towards Spring. Our season are caused by the fact that the Earth spins on its axis at a 23.5° to its path of rotation around the Sun. This creates longer, warmer days in the summer and shorter colder days in the winter in the Northern Hemisphere and the opposite in the Southern. In ancient times calendars started the year when equinox occurred. Our clocks also change to DST or what used to be BST on the night of 29th-30th March. Nothing to do with astronomy, more of a hangover from two world wars where it was considered that more time for farmers in the field would fill our food baskets.
Because of the angle of Earth’s rotation, the Sun will cross the Earth’s equator twice a year. This is called the Equinox. The Sun will cross equator on March 20th heading north until it reaches the maximum northerly movement to be over head at the Tropic of Cancer later in the year.
The day and night hours are equal at Equinox and this is the Spring Equinox, the point at which Spring is considered to start. Personally my spring starts when I see crocus, snowdrops and daffodils.
The original point of the crossing used to lay in the constellation of Aries and was called the First Point of Aries. Due to the circular toppling effect of the Earths daily rotation, called Precession, it is now in Pisces. This is also why the Celestial Pole positions change over a 26,000 year period.
For visual and photographic astronomers this will mean shorter nights with lighter skies at sunset and sunrise.
If you happen to walk along Kings Lynn old quays just before the Equinox you might notice the difference between high tide and low tide is even greater at the period of Equinox. The alignment of the Earth, new Moon and the Sun in a line with the Equator creates stronger tides.
The Moon
A New Moon will commence on the 1st March, and will be seen as a sliver in the western sunset skies a few days later. It will be 0.4˚ south of Mercury
It will reach full on 14th March. This is the last full Moon of winter and is often called the Worm Moon. This is because in times past when people were more connected with the land they would see worm casts more frequently on the surface of the fields as they become more active after winter. It is also sometimes referred to as a Crow Moon as crows were seen feeding on the worms. An older term from the Anglo-Saxons is Lenten Moon.
There is a partial eclipse of the Moon on 13-14th March but for us it will be mainly penumbral.
https://www.timeanddate.com/eclipse/lunar/2025-march-14
Moon & Sun
If it is clear there is a partial eclipse of the Sun on 29th March. In our area we can expect to see about a 40% exclipse. Look up from around 10:00-12:15 UT, maximum bite should be around 11:05UT
https://www.timeanddate.com/eclipse/solar/2025-march-29
The Planets.
Mercury is best seen on 8th March around 30 minutes after sunset..
Venus is bright at -4.2 magnitude when it is setting 3 hours after the Sun. It can also be seen 10˚ to the west of the waxing sliver of the Moon on the 2nd March.
Mars is getting dimmer and is in the constellation of Gemini and visible through most of the night
Jupiter: Is now in Taurus and of course we are starting to lose that winter constellation. On 1st March it is still at 58˚and by the end of March it will be at 40˚ altitude.
Saturn: Is at conjunction with the Sun and is no longer visible to us.
Uranus: Has moved from Aries into Taurus where it will be for the next 12 months.
The Constellations
My particular favourite this month is Leo, the constellation named after the lion. To me it is a harbinger of Spring, much like Orion being a foretelling of the coming winter. It has historical references dating back over 6000 years to 4000 BCE when the Mesopotamians named it as a lion.
Leo can be found in the southern aspect of the night sky, it’s head is formed by a sickle of stars which also look like a reversed ? Mark.
Leo has 5 stars of magnitude +1 or +2 making it easy to locate.
It’s brightest star is Regulus (Little King or Prince) which sits just above the line known as the ecliptic. The ecliptic is an imaginary line in the night sky along which the Sun, Moon and planets travel. It is actually the plane on which the Earth travels around the Sun, it is angled at 23.5º to our celestial equator. Ecliptic – Wikipedia
Regulus is also known as α (alpha) Leonis. The Greek alphabet is used to grade stars in a constellation in order of brightness. Regulus is a blue-white star about 79 light years distant, Blue-white indicates it is relatively young. A pair of binoculars will show it is a double star, its fainter partner is not visible to the naked eye at +7.7 magnitude. These two stars rotate around each other every 40 days. If there are planets associated with either star then anyone standing on them would get two sunrises and sunsets at least!
There are other doubles in Leo, look at the Wikipedia entry and see if you can see them.
There are also some interesting galactic clusters which can be seen in larger binoculars & telescopes or or as I intend by camera with long exposures, the on Messier objects M95, 96 & 105 and the Leo Triplet of M65, 66 and NGC 3628. They are a challenge. The Leo Triplet in February
To the west of Leo is a fainter constellation Cancer Cancer (constellation) – Wikipedia. It contains two nice Messier objects M44 and M 67. M44 ‘Praesepe’ or the Beehive cluster because it does resemble a beehive cone. It is a cluster of over 50 stars and is 590 light years away. One of a group of clusters nearest our solar system. M44 is easily visible as a binocular object. It was certainly a naked eye object in Greek times
M67 is a bit more of a challenge as it is fainter, mostly +10 magnitude stars. 200 of them lying 2,600 light years away.
In the Northern skies circumpolar Urse Major is now vertical with the pointer stars at the top.. The ancient Chinese astronomers called the stars that we recognize as the Plough of Big Dipper the Seven Regulators as their two vertical, upside down and horizontal positions as marking seasons. The Plough to the Chinese was the Rice Ladle (Bei Dou).
Cassiopeia and Perseus are well placed and that will allow those with binoculars and wide field telescopes to see the Perseus Double Cluster, a favourite of many especially our Chairman.
Keep looking up.
Frank Dutton FRAS
Frank Dutton (duttonlf@gmail.com)
