The Backyard Issue

Conditions were poor by any technical measure. The rate at the zenith should have been near a hundred an hour; from a suburban lawn with moonlight and a neighbour's security lamp, the honest count over two hours was nineteen.

Three of the nineteen were fireballs, and one of those left a train that hung visible for close to four seconds, which in a lifetime of watching is perhaps the twentieth time I have seen that.

Nineteen meteors in two hours is one every six minutes, which sounds thin and is not, because you are lying on your back in August with nowhere to be and the entire apparatus of the evening is a chair.

A word about the numbers, since they are the most misleading statistic in amateur astronomy and they disappoint somebody every single August. The advertised rate — “up to a hundred an hour” — is the zenithal hourly rate, which is a normalized figure describing what a single observer would see under a perfectly dark sky with the radiant directly overhead and nothing in the way. It is not a forecast. It is closer to a laboratory constant, and it is quoted in headlines as though it were a promise.

Real conditions cut it hard and they cut it multiplicatively. A bright moon might take sixty percent. Suburban skyglow takes half of what remains. A radiant at forty degrees rather than overhead takes a third more. Two of those together and your hundred is nineteen, and nineteen is what I counted, and the arithmetic was correct before I lay down.

This matters because the disappointment is preventable and the disappointment is what stops people coming back. Tell somebody a hundred and give them nineteen and they conclude the sky is boring. Tell them nineteen and give them nineteen and the fireball at 1:14 is the best thing that happened to them that month.

On technique, briefly, because it costs nothing. Get away from any direct light source, including the one over your own back door — the point is not darkness in the sky, which you cannot change, but darkness at your eye, which you can. Give it twenty full minutes before you judge anything; dark adaptation is not instant and most people quit at eight. Do not look at a phone, and if you must, turn the brightness to minimum and accept that you have spent about ten of your twenty minutes.

And lie down. Not a deck chair at forty-five degrees — flat, or as close as the furniture allows. Meteors appear anywhere in the sky and the human neck is not designed to hold a forty-degree upward angle for two hours. Every experienced observer I know owns something absurd for this purpose. Mine is a sun lounger from 2011 that lives in the shed eleven months a year and comes out for four nights.

The peak is not the only night. The Perseids run for weeks either side at reduced rates, the moon moves out of the way within days, and a clear Tuesday at fifteen an hour beats a cloudy peak at nothing. Nobody schedules for the Tuesday. The Tuesday is usually better.

The telescope is bought at Christmas, assembled with difficulty, aimed at a sky the buyer cannot yet navigate, and put in a garage by March. This is not a failure of the buyer. It is a failure of sequencing.

A pair of 10x50 binoculars costs eighty dollars, requires no setup, sits by the door, and will show you the four Galilean moons of Jupiter, the Andromeda galaxy, a genuinely startling number of double stars, and enough lunar detail to lose an hour on a terminator.

Learn the sky with those for a year. If you are still interested after a year, you now know what kind of telescope you actually want, and it is probably not the one at the department store.

I stood in the same driveway last month and counted what I could see. On a good night in the late nineties I could get the Milky Way from that spot — not well, but it was there, a smudge you could show a visiting cousin.

It is gone. Not dimmed. Gone. The limiting magnitude from that driveway is now about 3.5, which means a sky of perhaps forty stars where there were several hundred.

The cause is not mysterious and is almost entirely fixable: unshielded fixtures throwing light upward, and a switch to cheap blue-white LEDs that scatter far worse in the atmosphere than the old sodium. Shield the fixture, warm the colour, and most of it comes back within a night. There is no other environmental problem I know of with an undo button this direct and this ignored.