Five visible planets in the pre-dawn sky

Glenn K. Roberts groberts@isn.net
Published on January 7, 2016

Mercury will become visible in the morning sky, starting around January 20. The line-up of planets should help you to locate Mercury. The four morning planets from east to west: Mercury, Venus, Saturn and Mars. The fifth morning planet, Jupiter, lies outside the sky chart, in the southwest sky.

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Mercury, Venus, Mars, Jupiter and Saturn

Those who are up very early in the morning this month (and next) will have a unique opportunity to view all the five visible to the naked-eye planets — Mercury, Venus, Mars, Jupiter and Saturn — in the pre-dawn sky. The last time all these five planets appeared in the same sky together was during the period from Dec. 15, 2004, to Jan. 15, 2005.

This time around, the five visible planets will appear simultaneously in the predawn sky from about Jan. 20 to Feb. 20. Four of the five (Mercury, Venus, Saturn and Mars) will appear in the southeast-south region of the pre-dawn sky, stretching in a rough line from the lower left to upper right (the ecliptic), and will be visible about 70 minutes before sunrise. Venus will be the easiest to spot (it is the brightest of the four). Mercury will be visible (after Jan. 20) to the lower left of Venus, close to the horizon.

Moving up the line to the right from Venus, golden Saturn sits in all its celestial splendour. Venus and Saturn will be fairly close to one another during the first half of January. On the morning of Jan. 9, the two planets will stage a particularly close conjunction, the closest coupling of two planets since March 2013. Watch the waning crescent moon slide past Venus and Saturn before sunrise, both today and tomorrow.

Continuing further up the line, you will spot Mars. Though reasonably bright right now, Mars will, in May, shine as brightly as Jupiter does at present. Use binoculars to distinguish the differences in colour between the ruddy-coloured Mars and blue-white Spica, the brightest star in the constellation Virgo - the Maiden, which sits fairly close to the upper right of the Red Planet.

The fifth visible planet visible in the pre-dawn sky, Jupiter, sits in the southwest, having risen in the east before midnight at the beginning of January and around mid-evening (9 p.m.) by month’s end. Look for the waning crescent moon close to Jupiter on the mornings of Jan. 26-27.

Comet Catalina continues to move northward through the constellation of Bootes - the Herdsman into Ursa Major - the Great Bear this month, transitioning from an early morning object to an all-night object by month’s end.

Although the comet hasn’t brightened as much as predicted (mag. 6.5 as of 01/01/16 ), it is still sporting a dust tail and an ion tail, both of which should be visible in binoculars and long-exposure photos from a dark site away from city lights. Having reached perihelion on Nov. 15, 2015, Catalina is now heading back into deep space. The comet’s closest approach to Earth will be on Jan. 17, when it will pass approximately 100,000,00 kms from us.

This month’s full moon on Jan. 23 was often referred to as the “wolf moon” by the North American native peoples, in reference to the wolves howling hungrily outside their huts at this time of the year. The early settlers sometimes called it the “moon after yule”.

Until next month, clear skies.

Glenn K. Roberts is a member of the Charlottetown Centre of the Royal Astronomical Society of Canada (RASC). His column appears in The Guardian once a month. He welcomes comments from readers. Anyone who would like to comment on his column is encouraged to email him at glennkroberts@gmail.com.