Normally a few of the bright planets, Mercury, Venus, Mars, Jupiter and Saturn, are visible in night sky but it's rare to be able to see all of them at the same time. The good news is that over the next few weeks it's possible to spot all five "naked eye" planets in the morning sky just before sunrise. Such an alignment last occurred at the end of 2004 and the next opportunity will not take place until October 2018.

Venus is the brightest planet at magnitude -4.0 followed by Jupiter at magnitude -2.3. Saturn (mag. +0.6) and Mars (mag. +0.8) are roughly equal in brightness although impossible to confuse; Mars has a deep red hue and Saturn off white in colour. Mercury shines at magnitude +0.8 on January 24th, increasing in brightness to magnitude +0.0 at months end.

With clear skies observers will have no problem spotting Venus, Mars, Jupiter and Saturn. The difficult one is Mercury. It appears low down and requires a clear view of the eastern horizon to glimpse it. The planet is better placed from southern latitudes and next month will reach greatest western elongation (February 7th). In addition, this will be the most favourable time of the year to spot the planet in the morning sky from southerly locations.

The illustrations below show the positions of the five planets from mid-latitude northern locations and mid-latitude southern locations one hour before sunrise on January 24th and January 31st. The northern illustrations cover areas such as Europe, United States, Canada, China, Japan and Russia. The southern illustrations are valid from regions such as Australia, New Zealand, South Africa and South America. Depending on the exact observers location, the view may be slightly different to those shown below.

See also

The Planets this Month - January 2016