SHOOTING STARS
The UK-China Leonid Meteor Shower
Observation Project

It started with our Competition...

Our Write-a-Web-Page Competition resulted in the six winners visiting China for just over a week to observe the Leonids meteor shower. The competition was entitled The Threat From Space and required entrants to prepare a synopsis of the consequences of large meteorite impact to life on Earth.

Preparation...

November in this part of China is normally a pleasant month. If not warm it is at least mild. Usually. We had reports of lower than normal temperatures with night-time temperatures dropping below freezing, so we went prepared, with winter coats, gloves, woolly hats, scarves and body warmers. Some of the students brought sleeping bags and light matresses too. We also equipped ourselves with SLR cameras, tripods and other necessary photo-accessories. We obtained some diffraction gratings, so we could try some spectral photography of the shower. We fitted this to one camera and loaded it with black and white film to obtain a good spectral response right across the wave bands. We carried small torches and had tried to obtain red filters without success. Instead we purchased a box of Quality Steet chocolates and used the wrappers - very effective. We had pens and record sheets, and carried a small cassette player as another means of recording, which proved invaluable. We also took two digital watches which had been set using the internet atomic clock, and a digital thermometer.

The Winners met at Heathrow on Saturday 14th November...

The Winners were the guests of the British Council and the Haidian Youth Centre. We flew to Beijing by British Airways and were met by students from the Haidian district.

On Tuesday 17th November we accompanied sixteen Chinese students to the Mi Yun Observatory , which is part of the Beijing Astronomical Observatory. The weather was cold and dry, and extremely clear. The wind was quite strong but at sundown it dropped to almost nothing. The observatory itself is mainly used for radio observation and is located on a wooded hilltop beside the enormous Mi Yun Reservoir. For this reason, the grounds of the observatory are not suitable for sky-watching, but between the observatory and the water is an open south-facing field, from which it was possible to get an almost 360° panoramic view, horizon to horizon. There are only a few tiny villages in the area and consequently little light pollution.

We were well prepared for the cold, but no-one - including the observatory officials - expected the extreme low temperatures we experienced that night. Eventually the temperature dropped to minus 14°C. We were cold. Although the night was crystal clear and the stars were as bright as any of us had seen before, we were to be plagued by casual observers who turned up in cars and coaches, and carried torches like Mulder and Scully! In addition TV crews from as far away as Taiwan were on site to record the event. Needless to say they thought that banks of arc lights were a necessary accessory.

By midnight the area was like Piccadilly at Christmas. There was virtually nowhere to get away from the glare of headlights. We ended up in a dry riverbed that fed the lake, but this restricted our view to the horizon somewhat. Also, the car owners found they had no trouble driving across the frozen ground, so before long they were all over the field, drenching us with headlamp beams and getting stuck in ruts.

We set up our site just after midnight and shooting stars appeared almost immediately. The great majority were Leonids, their trails pointing back towards Regulus and Mars, which were just now visible towards the eastern horizon. Although we hadn't started serious watching until this time we had seen around a dozen meteors, just from casual glances at the sky, whilst wandering around the observatory. Most of these were fireballs, which left visible grey ion streaks in the sky for minutes after their light had faded.

As we got down to serious watching, and despite the inconvenience posed by our light-obsessed neighbours, we began to record a steady stream of fireballs and lesser objects - something between 30 and 50 per hour, and these were typically of magnitude one or zero, but magnitudes of -6 or brighter were seen. Colours ranged from blue though white to yellow and orange. Trails were left in the sky by at least half of them. Durations were typically of about half a second, with a variance from about a quarter right up to two seconds on a couple of occasions. Several conventional meteors were also observed, but these were, by and large fewer in number than the fireballs.

The most surprising feature was that the meteors and fireballs were seldom anywhere near Leo. The only common feature was that the trails all pointed towards the radiant. Any place in the sky to point the camera was as good as any other. We though, tended to face our lenses towards the south, to Orion and the ecliptic. However as it turned out, I had most success when I turned my camera towards Capella. I didn't know how sucessful at this at the time, I thought that perhaps I had acheived just one trace on film.

The cold soon bit our extremities and then deeper into our bodies. Gradually most of us devoted our efforts to keeping warm, it was difficult to concentrate on skywatching. We gave up written recording after half an hour or so: it was too cold to remove gloves, and writing in thick mittens in the dark was impractical, even with red torches. We did keep a taped record though. Until the batteries gave out. A similar fate was experienced by the other equipment, until eventually only the mechanical cameras worked. Even on a few of these though, the shutters jammed through cold. Fortunately, it was so cold and dry we had no condensation problems. By 02:30 local time, some of the students seemed to be suffering serverely from the cold, so some of us took a well earned break for an hour and trudged back to the observatory accommodation for hot chocolate and biscuits next to the radiator. We returned to the observation site an hour or so later in the hope of catching the peak develop, but it did not materialise.

Being extremely well wrapped up caused other problems: it tended to restrict one's view. With hood up and a scarf across the nose to prevent frost-bite, we had tunnel vision and restricted head movement. The walls of the stream cutting also restricted vision. Add to this the effect of headlights and we must have missed dozens of streaks across the sky!
 

Link to Sally's Expedition Diary .

Picture Pages - Pictures of the meteors and that freezing cold night

Reports Pages - Short reports from the Expedition members