Zdeněk Ceplecha
The Czech astronomer who calculated the first orbit of a meteorite from photographs, after the Příbram fall of 1959.
Key facts
- Born
- 1929
- Died
- 2009
- Nationality
- Czech
- Field
- Astronomer
Zdeněk Ceplecha worked at the Ondřejov Observatory near Prague, where in the 1950s astronomers set up cameras to photograph meteors from two places at once. By comparing the two views, they could work out the exact path of each meteor through the air.
On the night of 7 April 1959 a brilliant fireball was photographed from two of the stations. Ceplecha measured the photographs and calculated the fireball's path, its speed and where it should have dropped meteorites. Searchers found stones close to the predicted area near the town of Příbram, the largest weighing several kilograms.
Because the speed and direction were known, Ceplecha could also trace the meteoroid's orbit back around the Sun. It had come from the asteroid belt, between Mars and Jupiter. This was the first time anyone had linked a meteorite in the hand with its precise orbit in space, strong evidence that meteorites are pieces of asteroids.
Ceplecha went on to help build the European Fireball Network, with cameras across central Europe, and spent his career on the physics of fireballs, including how they slow down and break up. In 1991 he also worked on the fall of Benešov, whose fragments were found years later.
On the timeline
- 7 April 1959Příbram: the first meteorite with a known orbit