Excuse me Grandad, you promised us another star show after tea...so come on!
Righto. Let's head over there, away from the camp
lights. Bring the constellation pictures…and that groundsheet for us to lie on.
Here’s a torch with some red cellophane over it.
What's that for, Grandad?
If we use a bright torch the light will ruin our
night vision, so we look at the pictures using red light and these tiny colour-sensitive
cones in the back of our eyes. That saves the tiny rods next to the cones for
looking at the stars.
That's clever isn’t it!
Sure is - God is a clever designer. Now let’s start by finding the first 4
constellations - where did we decide to begin?
You said Virgo.
Okay. Even though Virgo is large she's a bit hard
to make out. You can’t miss Arcturus - in the north for us - and higher up, see
those two bright lights - the one on the western side is Spica which marks the
spike of wheat Virgo has in her left hand and the other light is the planet
Saturn on the hem of Virgo's dress at the moment. Of course, the people in the
northern hemisphere have to do the opposite to us, so when we look up from
Arcturus they have to look down to the south. Remind me sometime to show you
the rings around Saturn using a telescope.
Yea, cool!
Now looking down towards the west from Spica,
you'll see another brilliant star - that's Regulus on the heart of Leo the
lion. Nearly half-way back towards Arcturus there’s a not-so-bright star on
Leo’s tail, swishing Virgo's head.
Right...that's Virgo’s left hand and her head.
What about her other hand holding the palm branch?
Look a little bit further east from the lion’s tail
and you might be able to see another star, nearly under Spica. That's
Vindemiatrix on the palm branch, which was named for the women who picked
grapes in Ancient Rome.
Really??...except ‘Vinde’ would be above Spica for people up north. Okay Libra is next, Grandad.
True to name, the scales of justice are hard to
find, so we'll look for Scorpio first. Can you see a brilliant star to the east
of Spica and Saturn?
That's the gigantic star Antares on the
scorpion's head and the big long curve behind him towards the south, is his
tail.
Oh yea, that's easy to see.Now that we've found Scorpio we look for 2 fainter stars half-way between Antares and Spica. The more southern one is on top of the Libra scales and the other is on the left end of the beam.
Mmm ...not much to see there, except...I think I know which star is on the other end of the scales and I can see 3 stars in a line, sort of on top of each other. Where do they fit?
Yes, they’re on the scorpion’s right claw under
the base of the scales.
Now, the last one for this
evening is Sagittarius, the archer on horseback, aiming his arrow at the
scorpion. He’s hard to pick out but if you look down to the east from Scorpio’s
tail there’s a bright star marking the bottom of the archer’s bow and just
north of that there are four stars in a row, pointing to Scorpio – that’s his
arm pulling back the arrow. At least he will be the right way up for those
people up north.
I think Scorpio’s the best!
How
long will we have to wait to see the next four, Grandad?
We might stay up very late one night during the next
school holidays or else we’ll have to wait until December.
Off to bed now kids….story-time can wait ‘til the morning.
Good night Grandad and thanks for the star show!
NEXT: Born to die
http://discoveryiopna.blogspot.com.au/2013/07/born-to-die.htmlNEXT: Born to die
Image credit: abc.net.au
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