The Persieds

Persieds Radient, peaking Thursday night / Friday Morning

The main event this week has to be the Perseid meteor shower. They peak this year at 2 am Friday morning, so tomorrow night as late as you can manage is the best time for viewing. You need to look to the Northeast, there are no obvious stars nearby, the best way to find the radiant is to find Cassiopeia, which looks like a wonky W on its side. If you can’t find Cassiopeia, then I hope you can find the plough. Take a line from the two stars through the end of the dipper which takes you to Polaris, the North Star, keep going and you’ll find Cassiopeia. Now take a line from the lower internal diagonal in the triangle toward a couple of brightish stars and your there. Failing that just look to Northeast 30-40 degrees up, and if you don’t know where the Northeast is, have you considered suicide.

This year should be a good one because the moon is just off new and will be trailing the sun on the way to New York, it was 2007 when we last had a moonless Perseid Shower. If you’re a special type of Anorak you can count how many you see in a certain time and send the data in to the International Meteor Organization, who will compile it all and put it into a very interesting book. Though all this wholly academic because its bound to be overcast, but the Perseids will still be showing right up to the 22^nd.

The shower is caused by the Earth passing through the orbit of comet 109P/Swift-Tuttle, which is due back in 2016 when the show will be much more vivid.

We still have Venus, Mars and Saturn waltzing around very close to each other shortly after evening twilight in the west. Unfortunately this means that Saturn and Mars are on the other side of the Sun and are about as far away as they get. Venus on the other hand is getting closer to us and should be visible as a bright crescent in a good pair of binoculars.

Jupiter is up now well before midnight in south east and dominates the Southern sky for the rest of the night, you can’t miss it.

That was your Scilly stars for the week ending on 127th anniversary of the first public performance of the Dominican Republic.

The Flatulence Of The Sun

I take a week off and before you know its August, the month where the evening start to very noticeably start drawing in. And it’s not a bad month for looking at the night sky.

This week in particular if you look to the Northwest, Venus Mars and Saturn are almost on top of each other, especially on Saturday when they are within a 5 degree circle. Don’t worry about Mars and Saturn at first, just look for Venus which will visible very soon after Sunset hanging between Samson and the Bishop, looking from St. Mary’s. As the Sun sinks lower Saturn and Mars will come into view, all 3 of them should be easily visible at once in binoculars. By the end of August they will all be setting before 9, so this is the last chance to see them for a while. For this week at least, Mercury will be there but a lot closer to the horizon and may not be visible.

Yesterday Keri was banging on about the Aurora Borealis and he almost sounded like he knew what he was talking about, when the sad reality is that Keri is as much a scientist as John Prescott is a gay icon. Anyway you never know, there’s no moon of consequence for the next two weeks before midnight, so if you see some shimmering to the north it could just be the Northern Lights which are caused by the solar wind, a sort of Astral flatulence interacting with the earths magnetosphere. Which in turn is caused by the huge puddle of molten iron at the earth’s core?

Auroras are the result of the emissions of photons in the Earth's upper atmosphere, above 80 km (50 miles), from ionized nitrogen atoms regaining an electron, and oxygen and nitrogen atoms returning from an excited state to ground state. They are ionized or excited by the collision of solar wind particles being funneled down and accelerated along the Earth's magnetic field lines; excitation energy is lost by the emission of a photon of light, or by collision with another atom or molecule:


As for the moon this month first quarter was yesterday, its New on the tenth and full on the 24th.

And the other highlight of August is the Perseids Meteor Shower. The Perseids is one of the best meteor showers of the year, producing up to 60 meteors per hour at their peak. This year's shower should peak on the night of August 12 and the morning of the 13th, well after the moon has set. But you may be able to see some meteors any time from now to the 22nd. The radiant point for this shower will be, oddly enough, in the constellation Perseus. The thin, crescent moon will be out of the way early, setting the stage for a potentially spectacular show. For best viewing, look to the northeast after midnight.

I’ve put a guide on the blog. Of course the advent of the Perseids has now become a harbinger of doom. It is of course the time of year when the black shadow or she who walks by night begins her annual 8 and half months of plunder. Of course Barbara has already had virtually everything of value, but I’ve heard that this year she will be kidnapping elderly relatives for ransom, so you may want to put that Granny Flat on hold pending further developments.

And that was night sky for the week ending on the 39th anniversary of the founding of the Society for American Baseball in Cooperstown, New York.