To Infinity, and Beyond!
Because we're all space cadets, at heart.
|Our Previous Night Out|
|Date:||Friday January 2 2015|
|Conditions:||Clear, light breeze, -7 degrees|
Orion, King of Winter Skies
Come see this beautiful constellation all winter!
The constellation Orion bathes winter nights with vibrant, multicoloured stars. This glorious hunter is one of the brightest and most recognizable groups of stars in the entire sky. It is unfortunate that most of us do our stargazing in warmer weather, and miss this incredible display of stellar firepower. The constituent stars are supergiants, with luminosities 50,000 to 120,000 times our own sun. Their beautiful, romantic names are all Arabic, with the exception of Bellatrix, a Latin term for "female warrior".
We are familiar with constellation shapes like Orion; they comfort us with their constancy, and their place among the seasons. The ancients referred to all stars as "fixed", but this is not so: the average star moves at tens of kilometers per SECOND relative to us! However, distances are so vast between us and the stars in Orion that we don't notice them moving, even over our lifetimes. Constellations are visually deceiving: they appear to be stars that are grouped together. We are comfortable with this deception because the sky reminds us of an upside-down bowl, with pinpricks of light coming through. It looks like the stars of Orion are "together" up there. Nothing could be farther from the truth!
Take the three "belt stars" in the middle, for example.
They are from left to right: Alnitak, Alnilam and Mintaka. They look pretty close, right? Here's a side view of the situation (not to scale, of course!)
Alnilam is over 500 light years beyond Alnitak! It is difficult to overstate just how far beyond this star is.