Navigate with the Plough

This piece was originally broadcast on Radio Scilly in March 2019.

It’s been a glorious week for Scilly stargazers, with still, clear days turning into still, clear nights! What luxury, and after the disappointing Winter season, it’s been great to have several reliable nights in a row to gaze up and reacquaint ourselves with the starry blanket above!
 
When I do have a clear night, I like to test out my knowledge of where the constellations are, piecing together the sky in a map. After lots of clouds, where you might be snatching moments to find a particular object, an open sky offers the chance to get back to basics.
 
Here’s a constellation that will open up many others for you: Ursa Major, better known by its asterism name, the Plough.
 
It’s got to be the most well known groups of stars in the sky. Most people can point it out. Lesser know, is its job as a navigation tool!
 
The plough appears as 7 bright stars. You’ve got 3 forming the curved handle and then 4 forming a sort of bowl or shallow bucket shape. In France the plough’s known as the saucepan, for obvious reasons.
 
There are actually 8 stars in the plough as the handle includes double stars Mizar & Alcor. If you look for the second star in from the end of the handle you’ll easily make it out as a pair with binoculars or small telescope.
 
The brightest stars of the ‘pan’ part are those on the far right, Dubhe, top of pan & Merak bottom right of pan.
 
To find Polaris, trace a line from Merak up through Dubhe, then extend that line 5 times, until you reach the Pole star, less than 1 degree from true North.
 
Arc to Arcturus, by following the curve of the plough’s handle down, to reach distinctive bright, red star Arcturus in Bootes.
 
Cross the top of the bowl, continuing past Dubhe, leads in the direction of Capella – cap to capella!
 
And one more. Follow down the 2 stars of the pan nearest the handle (Megrez & Phecda), and you’ll reach Regulus, the brightest star in Leo. A hole in the bowl will leak on Leo, as the saying goes.
 
There are even more, but give those a go for now. And here’s to many more clear nights!