FAS geomathematician helps talented high school student with lunar gravity calculation

Vít Perkner, a student of Scioschool, took second place in the national round of the Secondary School Professional Activity in his category. Michal Šprlák, an expert from the Department of Geomatics at the Faculty of Applied Sciences, helped him with the topic Gravity Outside the Moon.

Vít worked with two models of the gravitational field of the Moon, i.e. with estimates of the gravity on its surface. He first performed calculations for both models and then compared the results in different regions of the Moon, such as higher and lower parts. "The similarity of the gravitational field models mentioned above depends on whether we compare the gravitational potential, gravitational acceleration or the growth of gravitational acceleration with distance from the lunar surface," Vit said. He subsequently developed a new method for estimating the density of the lunar crust and used it to perform the calculation.

"I looked for a density that best described the disagreement between the gravity field models used. In some basic features the resulting density agrees with existing estimates, but discrepancies can also be found. I am now working on verifying the correctness of the results", Vit adds. The task of finding the density of a body is ambiguous, so it is useful to compare the results obtained using different principles.

In the case of the Moon, such findings allow us, for example, to find the origin of craters, to investigate the composition of the lunar crust, or to obtain information about the thermal evolution of the Moon or the formation of the solar system.The proposed density estimation method can also be used to model temporal changes in the Earth's gravitational field reflecting, for example, the melting of glaciers or the rise in sea and ocean levels," adds Michal Šprlák. This issue is one of the objectives of the GACR project 23-07031S entitled "Ellipsoidal modelling of planetary gravity fields", of which Michal Šprlák is the principal investigator.

The gifted student appreciates the professional help he received from the supervisor. "His feedback was very helpful. In addition, Mr. Šprlák took the time to visit my thesis defence in the regional and national rounds and advise me on how to improve my speech," Vít Perkner appreciates. In the Physics SOTC, Vít had only Eduard Plice as his opponent. His work was also supervised by an expert from FAS.