May 2011, Stars over Wollumbin, our Southern Skies

In the month of May shining Venus dominates the planetary group in the pre-dawn sky,

keeping company to Mercury, Mars, Jupiter and invisible Uranus.

Mars is becoming brighter, while Jupiter is making now its first appearance since late March.

Saturn still reigns supreme over the night sky.


MERCURY met the Sun at Inferior Conjunction, on April 10. As the month advances our little brother will be nearly lost in the Sun glare in the month of May, edging closer and closer to the eastern horizon, making it difficult to spot without a pair of binoculars.

Finding Mercury will be easier by looking at Venus, because the two will move in unison in the pre-dawn sky, from the start of May to nearly the end of the month. On May 8 they will be at their closest.

The dawn sky will be in fact the best place for stargazing this month, with Venus, Mercury, Mars, Jupiter, and invisible Uranus, all clustered together against the backdrop of the constellation of the Ram (Aries) and the Whale (Cetus).

Mercury will rise before the Sun until late May.

VENUS remains the beautiful Morning Star until June 2011.  Like Mercury she is also edging toward the eastern horizon, but she is still high enough for great views. We should take advantage of this now because by June Venus will disappear in the Sun light to return only in mid-October as an Evening Star.

She is not alone, Mercury will be a close companion until May 25, with Mars and Jupiter near by. On May 7-8 Venus will be very close to little Mercury; on May 11 and 12 to giant Jupiter; and on May 23-24 to fiery Mars.

The snapshot below was generated by Stellarium for May 12, at around 5.30 am, looking East.

Click to enlarge

MARS emerged as a Morning Star around the middle of April. Its magnitude increases to +1.3 this month, making it slowly more visible in the pre-dawn sky.

Don’t forget to observe the conjunction Venus-Mars on May 23 when the two lovers will be only one visible degree apart.

The Red Planet will rise before the Sun until 2012.

The snapshot below illustrates just that encounter. It was generated by Stellarium for May 23, around 5.30 am, looking East, North-East.

Click to enlarge

JUPITER has been lost in the Sun glow since the Aries Equinox (March 21). He passed behind the Sun, at Inferior Conjunction, on April 6, and remained invisible until the end of April. In May we finally have a chance to see Jupiter again, grouped with Venus, Mercury and Mars.

Jupiter will be however too close to the horizon for best viewing. Try to spot him close to Venus and Mercury on May 11 to 14

The Sun reached its yearly opposition to SATURN on April 4, the best viewing time of the year.  Saturn is still visible all night in May, but becoming slightly fainter now, as the Earth slowly gains distance from it.

Saturn appears as a yellowish star, still transiting over the constellation Virgo, closely aligned to bluish Spica, Virgo’s alpha star. From May 12 to 15 the big Waxing Moon will transit close to both Saturn and Spica.


All the Sky Snapshots have been generated using Stellarium, a wonderful Planetarium freeware software.

Information for the Sky Events has been gathered from these web sites:


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