Professor reconstructs the far side of an asteroid
"My research is driven by pure curiosity. It's rewarding that you always find something
interesting as long as you dig a bit deeper. Compared with science, science fiction
is trivial and boring", says Mikko Kaasalainen.
Asteroids are like dinosaurs of space, they're fascinating and carry important information about the origin of our Solar System", describes Professor Mikko Kaasalainen.
In September 2008, the Rosetta spacecraft of the European Space Agency (ESA) flew past the asteroid Steins at a distance of 800 kilometres. During the seven-minute flyby the spacecraft gathered a wealth of important information on the surface properties of the asteroid.
Rosetta could not obtain images of the entire asteroid during its closest approach, because half of Steins remained outside of Rosetta's field of view. By using a mathematical method developed by Professor Mikko Kaasalainen from the Department of Mathematics of TUT, the shape of the entire asteroid was nevertheless reconstructed.
"We were able to reconstruct the entire asteroid by combining images taken by Rosetta with existing ground-based brightness observations of the far side of Steins, which were obtained as the asteroid whirls through our Solar System."
At the front line of space research
Kaasalainen developed the mathematical method for the OSIRIS team that was established for ESA's Rosetta mission. He was invited to join the team as its only Finnish member in 2005.
The OSIRIS team
- The science team of the Rosetta mission of the European Space Agency (ESA)
- A multicultural and multidisciplinary team with 47 members representing 11 different countries and 21 research institutions.
- Rosetta was launched in 2004.
- Rosetta zoomed past the asteroid Steins on 5 September 2008.
- The spacecraft will conduct another similar flyby past the asteroid Lutetia in summer 2010 before heading towards its final destination, the comet Churyumov-Gerasimenko. Rosetta will rendezvous with the comet in 2014.
- The measuring instruments and cameras onboard Rosetta provide information on the orbital motion, rotation, shape and density of the asteroids and the comet. The measurement results and images will open up a window onto the early history of Rosetta's flyby targets.
"I had experience of interpreting similar data sets and being involved in space research. I accepted the invitation with pleasure. I've always been fascinated by space as it offers an opportunity to explore major mathematical problems."
Kaasalainen describes his research assignment as a typical inverse problem. The objective was to infer the parameters of an object as accurately as possible by employing indirect observations.
"The method has since been applied to reconstruct other asteroids, too. It can also be used in computer vision and robotics applications to model objects based on limited information", says Kaasalainen, a member of the Academy of Finland's Centre of Excellence in Inverse Problems Research.
The Jurassic Park of space captivates the imagination
The OSIRIS team offered Kaasalainen a front-row seat to space research and the opportunity to devote his time to fundamental questions.
According to Kaasalainen, asteroids and comets have remained virtually unchanged for billions of years and thus carry a pristine record of the early history of our Solar System.
"Asteroids are like living dinosaurs that we can admire orbiting within the asteroid belt, the Jurassic Park of space. Maybe someday we'll be able to launch robot landers to the asteroids to dig up ore samples and return them to Earth for analysis."
Measuring carbon footprints
After the Steins project concluded, Kaasalainen has immersed himself in investigating other yet unresolved questions and shifted his focus from the early days of the Solar System to the future of our planet. He is collaborating with the Finnish Environment Institute and the Finnish Geodetic Institute in research projects that centre on global climate change.
"Research into climate change requires a lot of mathematical problem-solving, for example, to ensure that global warming forecasts are set within reasonable error limits."
Major political and financial decisions will be made based on the forecasts, so it is not immaterial how much scientists predict global temperatures to rise.
"I'm tackling another major challenge and that's just the way I like it. I thrive on solving mathematical problems that are not only scientifically challenging but also significant and influential on a general level", says Mikko Kaasalainen.