Thursday, June 11, 2015

Something interesting to see at night

If you are a nerd or a geek*, or maybe just a curious person, read on. Otherwise if I were you I’d go and read the blog of somebody more “normal” than me.

So there you are, on your boat out in the sticks, far from major habitation and human nightlife.  Its after dark and the washing up is done. You might listen to the wireless or watch TV, or you could go outside for a bit and see something interesting.  Being out in the wilds, you have the benefit of low levels of light pollution so if you look up you can actually see stars for a change.  Of course if you had a telescope you might see some special things, but let’s assume you haven't.  Well one star is pretty much like another to the naked eye, but there is recognisable stuff to see apart from the moon which I assume you can already recognise.  At this particular time there are a couple of things worth noting if the towpath hedgerow doesn’t obscure too much of the western skyline.

Fifty miles up in the atmosphere (that’s a long way) it is very very cold and very very very dry, in fact a million times dryer than air in the Sahara desert!  Even so, there is water up there in the form of tiny eeny weeny ice crystals, only 0.1 microns across.  At this time of the year on some nights these thin layers of ice crystals reflect the light from the sun just after dark and form quite bright cloud like structures.  They are called noctilucent  (night shining) clouds and are sometimes really pretty as they shine in an otherwise darkish sky.  Look out westward twenty or so minutes after sunset and you might get lucky.  Look ‘em up on Google images where you will see some lovely examples.

Another thing to notice at the moment  low in the western sky is the approach of Jupiter towards Venus.  You need to do this between about ten and eleven pm after which they will be setting below the horizon.  Venus is dead easy to spot as it is the brightest thing out there, not very far above the western horizon.  Jupiter is up a bit a and left a bit from Venus and is not so bright but still easy to see.  A good pair of binoculars might even reveal Jupiter’s moons as tiny shining dots in a row around the planet.  Watch the two planets each night as they draw closer and closer until about  July the first when the two planets will appear to be in the same place after which Jupiter will be the rightmost one.  Will they collide?  Hardly. Strange to think about it really as Jupiter is much further out from the sun than us, but Venus is between us and the sun.

Of course, if there is one, you could always walk to the pub instead.

*Of course (again) if you are a real geek then you already knew all this.  I didn’t, but I’ve been reading about it and thought somebody out there might be glad to know.  let me know if you see anything.

1 comment:

Anonymous said...

Fascinating - and so fortunate to see a noctilucent cloud - I understand that they're quite rare.

Sue, nb Indigo Dream