A meter accuracy at 1000 km distance: So precisely is the laser altimeter Bela, which will create a 3D map of mercury. Engineers behind the development of the University of Bern, and from Germany. The laser is so precise that you could measure the Alps from Hamburg.
The laser altimeter Bela consists of an infrared laser, which emits short bursts to the surface of the planet, and an ultra lightweight telescope that records the reflected pulses. The topography of the surface can then be calculated over the span, which was the laser pulse.
“So far, we had 2D images of the planet thanks to camera shots. Bela was created, to give us the analysis of the third dimension”, co-project director says Nicolas Thomas of the Center for space and habitability (CSH) of the University of Bern. “Bela is much to contribute, that we better understand mercury the planet in future.” The researchers on the precision can be particularly proud of the laser measuring system operates.
Only a meter deviation on 1000 km
Laser measurements are not on Earth. Much more complicated is the orbit of mercury. Why? Because the laser pulse is reflected from the planet is incredibly weak, and includes only a few hundred photons. At the same time, temperatures up to 200° c prevail in the orbit of the Sun next planet.
Despite these extreme conditions, the laser measurement system from Bern achieved an accuracy of under one metre at a distance of 1000 km. Thomas: “this is, as one would measure exactly the distance of one meter to the Eiger North face from Hamburg.”
When developing the scientists from Bern had support by the engineers of the Institute of planetary research of the German Aerospace Center, the Max Planck Institute for solar system research, and of the Spanish Instituto de Astrofisica de Andalucia.
“We have managed together with our partners from the industry in Switzerland, in Germany and Spain to produce a highly precise measuring instrument”, says Béla project manager Karsten SOAP Erlin. “Laser rangefinders are today normal on Earth. But such a device to produce that weighs less than 14 kg and measures distances over 1000 km in space, was an enormous challenge.”
Mercury played key role in relativity theory
On October 5, the Bernese researchers have passed her baby in the hands of the European Space Agency ESA. 2018 the laser altimeter with the BepiColombo mission aboard the Mercury Planetary Orbiter to mercury should break. Then is the long journey of 80 million km. 2024, the orbiter will finally swivel into orbit and begin its work.
Certainly, Albert Einstein would have been proud. For him, the intelligence on the movements of mercury were enormously important in the development of the theory of relativity. Thomas: “it’s a nice thought, that the University of Bern, where he was working, takes a leading role in the exploration of the planet with this instrument.”
For many years the NASA Messenger spacecraft has studied mercury. She was crashed by 2015 after the end of their mission to mercury.