Northern Hemisphere

Ian Morison tells us what we can see in the northern hemisphere night sky during March 2014.

Orion, Taurus, Canis Major and Gemini move into the western sky after sunset. Cancer is further east, and binoculars can be used to find the open cluster M44 - the Beehive Cluster - in this otherwise sparse area of the sky. Leo is rising in the east, and a number of galaxies can be found beneath his belly using a telescope. Virgo and Coma Berenices are lower down, and share a region known as the Realm of the Galaxies, wherein lies the giant Virgo Cluster. Bootes rises a little later, with its bright star Arcturus. Ursa Major, containing the Plough, is up to the north, and the rear two stars of the the Plough, Merak and Dubhe, point towards the North Star.

The Planets

• Jupiter is still well placed for viewing in the evening, reaching above 60 degrees' elevation. It shines at magnitude -2.4 and lies in Gemini, its retrograde (westward) motion reverting to a normal eastward progression on the 6th of the month and leaving it near to the star Mebsuta. A small telescope can pick out the four Galilean moons and, at certain times, the Great Red Spot in the planet's South Equatorial Belt.
• Saturn rises around midnight Universal Time (UT) at the start of the month and 22:30 UT by the end (bearing in mind that the clocks go forward one hour in Europe on the 30th). It is in Libra, and, during March, brightens from magnitude +0.4 to +0.3 and grows in angular diameter from 17.4 to 18.4". The planet begins retrograde motion on the 3rd as the Earth overtakes it in their orbits. Saturn's rings lie at 23 degrees to the line of sight, allowing features such as Cassini's Division to be seen with a small telescope or the Enke Gap with a larger one. However, Saturn does not get very high in the northern hemisphere sky at present.
• Mars is in Virgo, rising at about 22:00 UT at the beginning of the month and two hours earlier by month's end. Its brightens from +0.5 to -1.3 in magnitude during March, and grows from 11.6 to 14.6" in diameter as it approaches opposition (opposite the Sun in the sky) on the 8th of April. Its disc is about 91 percent illuminated, and surface features such as the north polar cap (tilted at 19 degrees to our line of sight) can be seen with a telescope. Mars spends the month a few degrees from the bright star Spica as it moves retrograde across the sky.
• Mercury reaches western elongation (its greatest separation from the Sun in the sky) on the 14th. It can be seen rising in the east-south-east about half an hour before sunrise, and its disc is 7.5" across and 50 percent illuminated in the middle of the month. The planet brightens from +0.8 to -0.1 during March, but cannot be seen very high in the sky.
• Venus reaches western elongation on the 22nd, and can be seen about 25 degrees above the south-eastern horizon before sunrise. It dims slightly from magnitude -4.8 to -4.4 this month, and shrinks from 32 to 22" across while its illuminated fraction increases from 36 to 54 percent.

Highlights

• It is still a good time to observe Jupiter in the evening this month. Its angular size drops from 42 to 38" during March, but you can still see many features through a small telescope, and the planet reaches its highest point in the sky relatively early in the evening.
• The constellations of Cassiopeia and Perseus are high in the west in the evening this month, allowing the Perseus Double Cluster to be found along the path of the Milky Way that runs between them. The star Algol, in Perseus, can also be seen to 'wink' roughly every 2 days and 21 hours, leading it to be nicknamed 'the Demon Star'. In fact, it is a binary star system in which the two stars occult each other in their orbits, causing the dips in apparent brightness.
• The asteroid Pallas can be located in the first week of March, when it approaches the second-magnitude star Alphard in Hydra. Its magnitude of +7 makes it easily visible in binoculars, and can be observed to move north night by night.
• Mars is only 4 degrees from a nearly-full Moon in the south-eastaround 23:00 UT on the 18th, and the star Spica is only 1 degree away from the Moon as well.
• Saturn is about 2 degrees from a waning Moon in the south-east around midnight UT at the end of the 20th
• Venus is less than 3 degrees below a waning crescent Moon in the south-east one hour before dawn on the 27th.