Your early morning planetary line up still stretches across the sky (west to east: Jupiter, Mars, Saturn, Venus, Mercury), but to see it, you have maybe a thirty minute window beginning around 7:15 a.m. when Mercury clears the horizon, until when the sky becomes too bright. Sunrise is currently two minutes earlier each day, so this is a limited time offer for this week only.
Twelve hours later we have that great winter southern sky. Using the Moon as a pointer again, the 11th finds it in Pisces, about eight degrees (a fist-width) to the right of Uranus; and six degrees to the left on the 12th. The Moon spends the next two days crossing corners of Cetus the Whale and Aries the Ram, and on the 15th will be found a couple of finger-widths to the right of the star Aldebaran in Taurus. After a couple of days passing through the upper reaches of Orion the Hunter, the Moon slides into Gemini the Twins early on the 18th.
Constellations are man-made patterns of stars that have varied over time. There are eighty-eight officially recognized ones today, and every star in the sky has been assigned to one of them. However, constellations are not what they seem. In reality, most stars that appear together in the sky have nothing whatsoever to do with each other.
We’ll start with an exception. Most of the stars in Ursa Major (the Big Dipper), are about the same age and live in the same stellar neighbourhood. This is far from true for most other constellations.
One of the two ‘twin’ stars for which Gemini is named is 33 light years away; its apparent partner is almost twice that far. Similarly, while Beteljuice in Orion is relatively near us, half of Orion’s belt stars are twice as far away and the other half are four to ten times further. In spite of appearances, Orion’s stars are nowhere near each other in space. Aldebaran, the brightest star in Taurus, is only half as distant as the ‘V’ of stars behind it, and only one-fifth as far as Taurus’s prime attraction, the Seven Sisters / Pleiades cluster. In truth, Aldebaran lies much closer to the stars of the Big Dipper than to any in Taurus. Even Sirius, the sky’s brightest star, is 50 times closer to the Sun than it is to any star in its own constellation. What you see bears little relation to reality.
Constellations are groupings of convenience: stars that lie along the same line of sight, not near each other in space. It’s merely an illusion we have created to help us make sense of the universe spread above our own back yard.
