near Geislingen (Germany) on Jan. 8th, 2011
report of an effort
to find the extra-terrestrial visitor, by members of the
Hermann Koberger, Fornach
On Jan. 8th, 2011, at 17:51h local time, a bolide stroke across the
evening sky in southern Germany. The bolide was witnessed by many, and
captured by at least two cameras in Switzerland and Austria.
Also roaring sounds and thunder were reported. Especially
the reports of sound being heard made (potential) meteorite hunter
One of the two known photographs of the bolide was made in Switzerland
by one of Mark Vornhusen's meteor-camera-network cameras. Being a
member of the German Meteorite
Forum, Mark posted his photo on the Forum, and soon after other reports
were shared, including a beautiful second photograph, made by Hermann
Koberger in Fornach (Austria).
As both photographs captured the bolide at angles almost perpendicular
to each other, this yielded a perfect opportunity to determine the
location of the track across the sky, and it's projection on the
earth's surface. The exact location of both cameras was known, and
because stars were visible in both photographs, combined with the know
time of exposure, directions could be determined fairly
ends in both photos could be calculated at about the same high above
the earth's surface (28 km). Track beginnings showed a difference. The
Swiss photo seemed to have captured the bolide somewhat earlier in its
flight. This could be explained by the larger distance to the track in
the Austrian photo, and the lower sensitivity of this camera. The
Austrian track was extrapolated to the Swiss photo's high at the
From the two photographs, Mark Vornhusen calculated the location of the
bolide's start and end point and their highs above the earth's surface.
He also collected wind speed information for different highs, and came
up with a first prediction of a possible fall area. It was situated
near the German city Geislingen an der Steige.
Forum members became excited about the idea to go out, and try to
find meteorites that might have reached the ground.
With a calculated bolide end high of 28 km (17.4 miles), there was
expected to be little chance of material being found however.
On the other hand, this looked to be an ideal opportunity to meet
Forum members, and have a great time "talking meteorite" with the equal
134 km (83 miles) to end of
(c) Mark Vornhusen
|282 km (175 miles) to end of bolide track
(c) Hermann Koberger, Fornach (Austria)
A video of the bolide can be found here (2MB):
Wind data showed that the wind had been blowing almost exactly in the
direction of the track. Many variables were still unknown, and had to
estimated. Fourteen Forum members agreed to meet on Friday evening, the
after the Bolide sighting.
Mark produced his final estimate for the strewn field shown below, and
the hunt was on!
(c) Mark Vornhusen
The day of the bolide, the possible fall area had been covered with
snow. Thaw removed the snow the week after, and conditions were ideal
for a hunt. Grass and leaves in the mostly farm land covered area were
flattened by the
snow, and possible meteorites could be expected lying on top of this
When we arrived at the hotel, we appeared to have booked about the
whole hotel! The bolide appeared to have boosted tourism. Next to our
team, also others were active in the area. For instance "team Svend
Buhl", a French team and solo hunter Thomas Grau.
I counted people from five different European countries, and from all
over Germany. A local
newspaper posted an article about the tourism boost.
had planned a first meeting for Friday evening at 22:00h.
In the hotel we had a room for
ourselves, that was used for discussions and planning. The
ones who arrived late were having their diner simultaneously.
Although most Forum members had never met, it was as if we had known
each other for years. Great camaraderie!
Martin had coordinated the
preparations in the days before the trip. Hanno provided a large
detailed map, three teams were formed and search
areas were agreed upon.
The aim for the next day was to search the beginning, the mid and the
Mark's predicted strewn field.
We had a lot of meteorite talks, laughs, beer, and it was much too late
when I finally went to bed...
(c) Hanno Strufe
(c) Hanno Strufe
The next day, a quick group photo in front of the hotel, and off we
arrived in farmland with endless meadows.
we "only" had one and a half day for our search, we decided to
concentrated on the easier meadows, and ignore the ploughed fields and
small patches of woodland.
Our GPS device was very convenient, to help us walk straight parallel
tracks across the meadows.
The author on his first ever meteorite hunt.
A stick came in handy, to distinguish soft animal droppings from
possible meteorites, without the need to bend over and feel...
had made numerous corridors and holes underneath the - disappeared -
Not to be confused with impact holes...
Typical landscape to the south west of Geislingen
large area was searched that first day.
We didn't find any meteorites, but the evening of that first day in the
fields, we had a great time of togetherness again.
"Team Svend Buhl" paid us a visit, and information
was being exchanged.
Later that evening also solo hunter Thomas Grau came in to say hello.
Of course there were sore muscles and a little disappointment of not
finding meteorites. But we had a lot of fun, admiring and
discussing meteorites that had been brought by several Forum members,
and were being passed around.
It was great to be able to discuss meteorites with equal minded.
For me - as a foreigner - it was also a great opportunity to practice
my German :-)
day, based on a
theory of small fragments, and a larger drift by wind, we decided to
search another area, at a larger distance from the bolides track
end, near Schalkstetten.
We were looking for 1 to 10 gram pieces this time. It was a beautiful
sunny day, but sunshine and shadows made it harder to distinguish
did this hole come from???
meteorites were found that day.
Soon after noon, the search
was ended, and we had to start diving home again. For me this
meant driving for eight and a half hour.
Fortunately, I had a Forum
needed a lift as a companion.
Time flew, and when I arrived home that
evening, that was the end of a great experience of companionship with
equal minded, that
surely made the trip worthwhile, even without finding any travellers
A special Thank You goes to Mark Vornhusen who made this all possible,
by sharing his photograph of the bolide and his calculations on the
German Meteorite Forum.
Thomas Grau and others planned to continue the search. A few days later
however, snow returned, and futher search efforts had to be
After the weekend, at the
Forum, trajectory calculations were discussed. Influence of
and shape of fragments, air density and windspeed as a function of
heigh, specific mass, drag coefficient as a function of Mach number,
Also placing of additional meteor cameras was concidered. This surely
will result in a Forum, that will be even better prepared in case of
future bolide sightings and subsequent search efforts.
I'm looking forward to the next big one!