Three Kharkiv scientists from the Research Institute of Astronomy of Kharkiv Karazin National University took part in research activities undertaken during the Rosetta unmanned spacecraft mission, which took 10 years and 8 months to reach comet Churyumov-Gerasimenko.
“The spacecraft, launched by the European Space Agency (ESA), had its lander making the world’s first soft landing on a celestial body on November 12, as all earlier probes ‘fell’ rather than landed,” we learned from Ivan Sliusariev, a researcher working at the department of physics of asteroids and comets of that Kharkiv research institute. “In fact, there were ways to cover millions of kilometers-long distance to the asteroid ten times faster. The Rosetta took so long to arrive there because it had a complex orbit and did gravitational acceleration and fuel economy maneuvers,” 27-year-old Sliusariev explained. When the Rosetta was launched in 2004, he just graduated high school. However, the mission already involved head of the department of physics of asteroids and comets Professor Iryna Belska as well as researchers Vasyl Shevchenko and Yurii Kruhly. Participation of Kharkiv astronomers comes as no surprise, since the city has hosted a strong team of asteroid and comet scientists since the late 1970s, and Kharkiv researchers were guests of honor at the observations of the comet held in 2004. It was Professor Belska who co-authored the article prompting the ESA to select two asteroids, Steins and Lutetia, as the mission’s objectives. The Rosetta flew by them in 2008 and 2010, respectively. The Kharkiv scientists conducted ground observation of Steins and Lutetia as the probe approached them. Having done her Candidate of Science degree thesis on these asteroids, Belska took part in the processing of the data obtained from them, and got a unique opportunity to test the results of her calculations many years later.
“We have measured reflectivity of Steins for the first time, allowing us to figure out what substance the asteroid is made from,” Sliusariev explained. “The flyby of Lutetia made it possible to determine the mass of the asteroid and its density. Lutetia has been found to be denser than the other asteroids and similar to metallic meteorites that fall to Earth.”
The data obtained on the flybys of the asteroids have confirmed the results of ground-based observations. For example, the shape of Lutetia has been found to be not convex. It has turned out that the sizes of the two asteroids were determined mostly accurately.
The study of asteroids not only helps us to understand the processes that took place during the formation of the solar system, but also contributes to the development of ideas about the future use of asteroid resources, like metals or diamonds. Sliusariev said that the Rosetta would circle Churyumov-Gerasimenko comet for another year, and possibly would then make a soft landing on an asteroid as well.
The contribution of the Kharkiv astronomers to the grand mission and the new data obtained in the course of the Rosetta journey will be covered by the researcher in a public lecture he will deliver at the Indie club on November 23 as part of the Free University project, conducted by the Maidan Monitoring news agency.
