[meteorite-list] ESA Scientists Capture The Lion's Offspring Down Under

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:47:14 2004
Message-ID: <200111282233.OAA09731_at_zagami.jpl.nasa.gov>

ESA Science News
http://sci2.esa.int/leonids/leonids2001/

Contact:

Dr. Detlef Koschny
ESTEC, Noordwijk, Netherlands
Tel: +31-71-565-4828
Email: detlef.koschny_at_esa.int

28 November 2001

ESA scientists capture the Lion's offspring Down Under

After an eventful trip to the other side of the world, ESA's intrepid
scientists have returned with a treasure trove of data about the 2001
Leonid meteor shower.

>From their remote encampment in the Australian outback, the four-man
team from the European Space Research and Technology Centre in the
Netherlands successfully observed many thousands of shooting stars
while carrying out some groundbreaking trials of new scientific
experiments.

Team leader Detlef Koschny and colleague Roland Trautner happily
recounted their successful campaign to capture the Lion's offspring.

Question: Were you able to see the Leonids as you had hoped?

Koschny: We were rather nervous because the night of the predicted
maximum was cloudy -- the first cloudy night we had in Australia --
but, fortunately, the clouds went away and we had three hours of
beautiful Leonids. We saw the first Leonid fireballs through holes in
the clouds -- this led to quite spectacular views, since the clouds
were black and basically invisible (an unknown experience to a European
observer, where there are always lights to illuminate the clouds).

Miraculously, it slowly but steadily cleared up and one hour after
midnight we had beautiful skies: the Magellanic Clouds were blazing,
Canopus, Sirius and Achernar brilliant. The show started with about
one bright Leonid (-2 magnitude or brighter) per minute. Most of them
had orange-yellow heads and left a blueish-green trail that lasted
for a few seconds. A small number showed persistent trails for half a
minute or so. The highlight was a -2 mag Leonid which flew just above
the southern horizon, parallel to it for about 90 degrees!

Trautner: It was a great show -- amazing! The most spectacular view
for me was in the morning twilight (on 19 November), when the Sun was
painting the sky a cobalt blue, the bright stars and the Milky Way
were still visible, and there were brilliant fireballs coming in. It
was the most beautiful moment of the whole night.

We were very lucky because we had good weather at the end. There had
been cloud and smoke from bush fires earlier in the night. The bush
fires last for weeks -- the farmers just let them burn. We could see
them getting closer until they were burning near the road we would
have to use on our return journey. Fortunately, the fire was already
extinguished when we made our way back to Broome.

Koschny: The weather was a worry to us. There had been thunderstorms
around Perth, and we were told that the weather was also bad around
Wolf Crater, so we decided to camp out at a dry lake nearer Broome.
We made the right decision.

Question: It sounds as if your observations were successful.

Koschny: We captured many meteors and fireballs on video -- probably
several thousand in total, though we won't know the actual numbers
until we analyse our tapes. At one point I saw five meteors within
one second. My impression was that the activity was fairly constant
for about three hours. It was definitely less activity than the 1999
Leonids that we had observed from Spain. There didn't really seem
to be a significant peak, but this may be because of the observing
geometry. We saw a bright fireball every minute at first, when the
radiant (the apparent source of the Leonids) was low above the
horizon. Later, as the radiant rose higher in the sky, we could see
a lot more, fainter meteors.

Our visual observations were reported via satellite phone to Vladimir
Krumov from the International Meteor Organisation, who kindly acted
as the coordinator. We obtained about 200 hours of video data from
five intensified video cameras. Two of the cameras were equipped
with objective gratings, so we were able to successfully record
meteor spectra showing both emission and absorption lines, and we
can now start to analyse the chemistry of these meteors.

We also got some nice recordings from the electric field sensor that
was measuring the electric field of the atmosphere. The signal was
converted to the audio range and recorded on the video tape of our
wide angle camera. Although the camera shows about 200 meteors
brighter than +1 mag, so far we have not found (heard) any obvious
correlation between the electric field and a meteor. We will be
analysing the data in detail over the coming weeks to see if we can
find any evidence of this.

Trautner: We suffered from high temperatures -- above 40 C every
day. This increased the electric current consumption of the MI probe
electronics and blew the fuses. Another problem we encountered was
the power supply for our equipment. Fortunately, we were able to
recharge our batteries during the day using a solar panel and by
linking up to our car batteries and generators. The solar array was
very useful -- it would have been a disaster if the car batteries
had run dry!

After a number of MI probe test runs, the display on the laptop
controlling the probe died, so that brought my tests to a sudden end.
However, I had run sufficient tests before that to get plenty of
useful data. It will be very valuable for assessing the performance
of the new instrument architecture.

Question: You mentioned the threat from bad weather, heat and bush
fires. Were there any other problems that you had to overcome?

Trautner: We were driving around looking for a good site to set up
the MI probe when we had an encounter with a farmer's daughter
wielding a rifle! She did not realise that her father had given us
permission to be on the property and thought we were trespassing.
She told us in no uncertain terms to get off the property. It was
only after she rang her father that she realised her mistake. She
wrote us an apology afterwards.

We also had to keep a look out for lizards. Some of them were up to
1.5 metres long and they looked like small crocodiles! They were very
shy, but if we saw any of these animals, we were very respectful! We
also saw a lot of other animals -- kangaroos, bush turkeys, emus,
etc. There were plenty of insects too -- sometimes they were a real
plague.

Koschny: All in all, it was a fantastic experience. Especially
sitting in the outback, with nighttime temperatures above 20 deg C,
three hours away from civilisation, seeing the Magellanic Clouds
and the Southern Cross, was something I will never forget.

Links:

* Leonids Down Under pages
  http://sci2.esa.int/leonids/leonids2001/links.htm
* Leonids meteor page
  http://planetary.so.estec.esa.nl/meteors/ and navigate to "Leonids01"

[NOTE: Images supporting this article is available at
http://sci2.esa.int/leonids/leonids2001/]
Received on Wed 28 Nov 2001 05:33:22 PM PST