Age: 10 days old
Phase: Waxing Gibbous
Distance: 402,102 km
Ian Morison tells us what we can see in the northern hemisphere night sky during March 2015.
Orion, Taurus, Gemini and Canis Major are setting in the west in the evening. Gemini is the highest of these, with its bright stars Castor and Pollux representing the Heavenly Twins. Further east is Cancer, whose Beehive Cluster can be seen with binoculars and which is currently home to the planet Jupiter. Further over still is Leo the Lion, with its bright star Regulus. Bootes, containing the star Arcturus, is rising in the east. The Plough, an asterism within Ursa Major, is high overhead, its back two stars, Merak and Dubhe, pointing towards Polaris, the North Star. Capella, the yellow star in Auriga, is also high in the sky.
- Jupiter reached opposition (opposite the Sun in the sky) on the 6th of February, and is still high in the south late in the evening. During March, it dims from magnitude -2.5 to -2.3 and shrinks from 44.5 to 41.6", as it moves retrograde (westwards) towards the Beehive Cluster in Cancer. A small telescope allows you to see the equatorial bands, the Great Red Spot (at certain times) and the four Galilean moons.
- Saturn is in Scorpius, near the leftmost star of the fan representing its head, and rises at around midnight UT (Universal Time) at the end of March. It grows from 16.9 to 17.8" during the month, as it brightens in magnitude from +0.4 to +0.3. Though no higher than 22 degrees when visible in the UK and therefore subject to significant atmospheric distortion, it is high enough in the south-south-east before dawn to make out its ring system using a small telescope, as this is now some 25 degrees from our line of sight. Saturn switches from eastward to westward motion relative to the stars around the 11th.
- Mercury sinks into the Sun's glare at the beginning of March, so is is not a good month to observe it.
- Mars starts the month on the boundary of Pisces and Cetus, before moving eastwards and entering Aries on the 30th. It dims from magnitude +1.3 to +1.4 during March, while its disc shrinks from 4.3 to 4". It is best seen about 15 degrees above the western horizon as darkness falls. It is just 18' above Uranus on the 11th.
- Venus has become an evening object, appearing higher above the horizon each night. Shining at magnitude -4, it dominates the western sky an hour after sunset. Its angular size increases from 12 to 14" over the month, and its illuminated fraction wanes from 86 to 78 percent, but it still appears blurred by atmospheric turbulence due to its relatively low elevation.
- A partial solar eclipse is visible across the UK at around 09:00 UT on the 20th. It is total in some places between Scotland and Iceland, such as the Faroe Isles. To avoid damaging your eyes, don't look directly at the Sun unless you are wearing dedicated eclipse glasses. Alternatively, project an image of the Sun by making a pinprick-sized hole in a piece of foil and allowing the sunlight to shine through it into a dark hollow such as a shoebox.
- Venus and Mars lie close together after sunset from the 1st to the 7th, with Uranus about halfway between them at the end of this period.
- Venus and Uranus are just 6' apart in the sky on the 4th. Venus, at magnitude -4, is some 10,000 times brighter than Uranus, which requires binoculars to be seen at magnitude +5.9. In order to see the fainter object, you may need to use a telescope and eyepiece with high magnification, so that you can move Venus out of the field of view.
- Mars is just 2 degrees from a waxing crescent Moon after sunset on the 21st, low above the western horizon.
- Venus is only 3 degrees from the waxing crescent Moon on the evening of the 22nd.
Claire Bretherton from the Carter Observatory in New Zealand speaks about the southern hemisphere night sky during March 2015.
The evenings are drawing in as the autumnal equinox passes on the 21st. The summer constellations of Canis Major, Orion and Taurus are in the north-western evening sky. The brightest star in the night sky, Sirius - Takurua to Maori - is almost overhead, with Rigel and Betelgeuse below. Between them is Orion's Belt, three stars that are known as Tautoru in New Zealand. It points down through the head of Taurus the Bull, which contains the Orange star Aldebaran as the Bull's Eye. This V-shape also hosts the Hyades Cluster. For observers with binoculars or a telescope, over 100 stars brighter than 9th magnitude can be seen. Below the V and near the horizon is the Pleiades Cluster, representing the half-sisters of the Hyades in Greek mythology. Called Matariki in New Zealand, their first pre-dawn rising each June marks the Maori New Year.
The second-brightest night-time star, Canopus, is high in the south-west, with the blue star Achernar slightly below. The two of them form a near-equilateral triangle with the south celestial pole, around which the sky appears to rotate. Although this point lacks a nearby bright star, the constellation of Crux (the Southern Cross) helps to locate it. High in the south-east in the evening, Crux is accompanied by the Pointer Stars, Alpha and Beta Centauri. To find the pole, point one hand at Gamma Crucis, the star at the short end of the Cross, point the other hand at Achernar and then bring the two hands together in the middle. This should point you south.
The two dwarf galaxies known as the Magellanic Clouds are visible to the naked eye as two fuzzy patches near to the south celestial pole. Each contains billions of stars, and the Large Magellanic Cloud is the higher of the two. Binoculars or a small telescope can pick out some of its star clusters as individual patches of light within it. A bridge of gas connects it to the Small Magellanic Cloud, demonstrating tidal interaction between the two. It is easiest to spot them around New Moon on the 20th, when they are high in the south after dark.
- Jupiter dominates the northern sky this month, setting in the north-west in the early hours of the morning. The Moon passes close by on the 3rd and 30th.
- Venus appears briefly at dusk, low in the west. It sets about an hour after the Sun at the start of the month, rising to 1.5 hours by the end. In the middle of next month, it will begin to remain visible until after twilight.
- Saturn rises in the east before midnight NZDT (New Zealand Daylight Time, 13 hours ahead of Universal Time) at the beginning of March, and before 22:00 at the end. It sits just below the Claws of Scorpius the Scorpion, which is a winter constellation known as Te Matau a Maui to Maori. This represents a mythological hook that was used by Maui to catch a large fish that became the North Island of New Zealand. The red star Antares is higher and further south than Saturn, and represents the Scorpion's Heart - to Maori this is Rehua, a drop of blood from Maui's nose that he used as bait for the hook. A small telescope reveals Saturn's rings and its largest moon, Titan. Titan is the only known moon with an atmosphere, and the only body in the Solar System - apart from the Earth - with liquid lakes on its surface, although these consist of methane rather than water. Our own Moon appears close to Saturn on the 12th.
- Mercury is coming to the end of its best morning apparition of the year. It rises in the east around 05:00 NZDT at the beginning of March, but becomes lost in the morning twilight by the end as it appears less than an hour before the Sun.