Watching Falling Stars

[major_clanger]

The dust particle has orbited the Sun for thousands of years, shed millennia ago from the miles-wide chunk of dirty ice that is the nucleus of Comet Swift-Tuttle. Since then it has followed its parent comet's orbit dozens of times, lingering for decades in the outer reaches of the solar system in between its century-spaced plunges through the realm of the inner planets. Today, it once more makes its closest approach to the sun, an approach that takes it across the orbit of Earth.

Today, Earth happens to be there.

Nine o'clock, and heading back from the Cambridge pub meeting. I'm still a little worn out from ConteXXt, and an early bed looks like a welcome idea. But the sky is strikingly clear, sunset colours shading into inky blue-black, with a brilliant crescent Moon setting low in the west. It will be clear skies for the night of August 12th, which means that despite the weather of the last few days there might be a chance of seeing the Persied meteor shower after all.

The particle fell past the Moon's orbit a little while ago. Now the Earth - a blue-white crescent from the direction of its approach - is swelling against the stars.

After a quick email and LJ check, I go out the back to check up on the sky. Clear and cloudless, with the stars sharp and bright in the way they often are after rain has washed the dirt out of the atmosphere. I do not have to wait for long before a sudden bright streak is etched across the sky - it is Perseid maximum tonight, and on average there will be a naked-eye meteor every minute or two.

Unfortunately, the view from our back garden is hemmed in by trees, restricted to a patch overhead. If I'm to stand much chance of seeing more of the display, I'll need somewhere with a better view. I grab my fleece, thermal-lined woolly hat (you learn some things early on as a stargazer, especially one with thinning hair), my 7x50 binoculars and a folding lawn chair, and drive off for my local observing site.

The Earth is close now, only a few tens of thousands of kilometres away. Perhaps the dust particle has been this close before, but this time there is no doubt; this time, it will not miss.

Not long after moving to Huntingdon last year, I started scouting out good stargazing sites. I wanted somewhere away from streetlights, relatively secluded (so as not to be the likely haunt of the local mischief) but easy to get to. Brampton Wood proved ideal, only two kilometres away on the map (although rather further to drive), it is a small nature reserve that despite lying less than a mile off the A1 is only accessible via a single-track road that links the back ends of two small villages. I park in the tiny gravel car park at the edge of the wood, carry my seat through the access gate and walk fifty metres up a path to a moderately-sized clearing. By day, this is the arrival point for visitors to the wood, complete with a small shelter holding information posters detailing the wood's wildlife. Now, it is a sheltered observing ground providing an
excellent view of the night sky.

I set down my chair facing south. This is away from the shower radiant, but this gives perhaps the best chance of seeing meteors, as I will be looking at them as the pass me, rather than head-on. As my eyes adapt to the darkness, the patterns of the constellations fade into the broader sprinkle of stars, the milky way cutting a faintly luminous swathe across the sky. Small dots of light drift past: satellites. I've checked the predictions website before coming out, and seen that tonight's appearances are mainly the upper stages of Russian satellites. Each of those dots is a tumbling cylinder of aluminium and titanium, blasted into space from Tyuratam or Plesestk to do its job for a few brief minutes before following its payload into orbit. One day it will fall to earth like the meteors I am here to watch, but for now each one skims smoothly on to disappear behind the trees.

And the meteors themselves. Every minute or two another sharp streak flicks across the sky. They arrive at random; for minutes at a time there will be nothing, and then two or even three meteors will follow in quick succession.

The particle is very close now. The world ahead of it is fast unfolding into a landscape under it. Sparkles and flashes ahead of it show where its fellows are meeting their brief but spectacular ends.

Now and again I take a break from meteor-watching and raise the binoculars to my eyes. Sometimes I look for a particular target - the Andromeda galaxy is an easy fund, a hands-breadth below the crooked 'W' of Cassiopeia - and sometimes I just slowly sweep through the star-clouds of Cygnus, marvelling at the endless scattering of suns. The woods are surprisingly noisy, with the odd crack of twigs and muffled sounds of movement adding to the chorus of crickets and reminding me that there is other life than just me out here tonight. Rabbits mainly, but there are a few deer around as well.

It is past midnight now, and tempting as it is to stay I am back at work tomorrow. Besides, clumps of cloud are now rolling in. I take one last look up at the sky.

The dust particle slams into the upper atmosphere. The wisps of air are a miniscule fraction of the density at sea level, but to a mote of dust travelling at tens of kilometres per second they are barrier enough. In milliseconds the particle is transformed to a ball of superheated plasma, shedding its kinetic energy as a flash of light visible over a broad stretch of East Anglia, a hundred kilometres below.

A final, and particularly bright, Perseid etches a luminous trail across Draco and Cygnus. Enough for tonight. I pick up my chair and head back for the car, and home.

MC

Comments

[purplecthulhu.livejournal.com]

Sounds like a very good night of Perseid watching! Unsurprisingly, not a lot was
visible from Bethnal Green.

Good description too - the writing style is perhaps a little Baxterian perhaps?

Glad you're recovering from Contexxt - hope it wasn't too stressful for you both!