SkyEye

The Calendar

As in January, the Moon becomes full twice this month, with the second one popularly called a 'Blue Moon'. Mars gives astrophotographers something to look at on 20 March when it passes near M8, the Lagoon Nebula.

The Solar System

The word planet is derived from the Greek word for 'wanderer'. Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars. Dwarf planets and small solar-system bodies, including comets, are not so constrained, often moving far above or below the ecliptic.

Sun Aquarius → Pisces

The solar south pole is most inclined toward the Earth early this month.

Mercury Aquarius → Pisces

The closest planet to the Sun begins the month rising higher in the western sky after sunset. On the fifth day it has a close encounter with Venus, appearing less than 1.5° north of the brighter planet. By mid-month, it is falling towards the horizon and soon disappears for southern hemisphere observers. Views of this elusive planet are better in the nothern hemisphere, with Mercury staying above the horizon until late into the month. Mercury reach greatest elongation east on 15 March and changes direction, direct to retrograde, on 22 March.

Venus Aquarius → Pisces → Aries

The evening star is best seen from the northern hemisphere as it rises rapidly above the western horizon after sunset. It's getting higher in the sky as seen from the southern hemisphere too but not to the same extent. On 5 March, Venus appears just south of fellow inferior planet Mercury. It has another planetary close encounter on 29 March when it passes 0.1° south of Uranus. Optical aids will be necessary to spot sixth-magnitude Uranus next to bright Venus in the twilight.

Earth and Moon

On 20 March, Earth reaches equinox. The word equinox means 'equal night' so that on this day, the (centre of the) Sun spends an equal amount of time above and below the horizon everywhere on the planet.

The second Full Moon this month is often called a Blue Moon. It is the second Blue Moon to occur this year, the first happening in January. The first-magnitude star Regulus is occulted twice this month, on 1 March and again on 28 March. Aldebaran in the constellation Taurus also falls victim to the Moon on 22 March.

Mars Ophiuchus → Sagittarius

The red planet passes less than a degree north of the open star cluster NGC 6530 on 20 March. West quadrature, that instant when Mars appears 90° away from the Sun, occurs on 24 March. Due to its southerly declination, the red planet is most easily seen from equatorial and southern latitudes.

Jupiter Libra

Now rising around midnight, Jupiter is still difficult to see from the northern hemisphere as it remains low in the sky. On 9 March the gas giant reaches a stationary point and reverses direction, going into retrograde.

Saturn Sagittarius

Still a morning sky object for northern hemisphere observers, the ringed planet now rises just before midnight for viewers in the south. At west quadrature on 29 March, the interplay of shadows — disk, rings, satellites — in the Saturnian system are at their most pronounced.

Uranus Pisces

This greenish-coloured planet is getting increasingly difficult to see in the evening twilight as it approaches conjunction with the Sun next month. It has an extremely close encounter with Venus on 29 March.

Neptune Aquarius

A small telescope is necessary to view the most distant planet in the solar system but potential observers won't get much joy this month. Neptune is at solar conjunction on the fourth day and lost to view in the glare of the Sun.