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The Geotourism Students’ Scientific Club (GSSC) is operating at the Department of General Geology and Geotourism of AGH University of Science and Technology (AGH UST), bringing together young enthusiasts of Earth sciences, at the Faculty of Geology, Geophysics and Environmental Protection. It has been operating continuously since 2003. The primary objective of the GSSC is to arouse interest in scientific work in the field of Earth sciences, as well as to popularise geotourism in the student community. The article reviews the most important achievements, events and activities documenting the long-term accomplishments of the GSSC. The greatest successes of the GSSC include the implementation of five rector’s grants and active participation in national and international scientific conferences. It is worth noting, that the GSSC organises its own “Geotourism” conference session as a part of the Conference of Student Special Interest Groups of the Mining Division. The members of the GSSC promote geology and geodiversity, explaining it in a manner which is comprehensible to an average person. Over the last dozen or so years, they have undertaken various activities, and some of them have become a tradition. Themed evenings and meetings with experts “That’s how it’s done!” attract a large audience from the university and beyond. Annual domestic and foreign educational and sightseeing trips, culminating in a trip to Iceland in 2022, have become an integral part of the GSSC activities.

Main Belt Comets (MBCs) exhibit sublimation-driven activity while occupying asteroid-like orbits in the Main Asteroid Belt. MBCs and candidates show stronger clustering of their longitudes of perihelion around 15{\deg} than other objects from the Outer Main Belt (OMB). This potential property of MBCs could facilitate the discovery of new candidates by observing objects in similar orbits. We acquired deep r-band images of 534 targeted asteroids using the INT/WFC between 2018 and 2020. Our sample is comprised of OMB objects observed near perihelion, with longitudes of perihelion between 0{\deg} and 30{\deg} and orbital parameters similar to knowns MBCs. Our pipeline applied activity detection methods to 319 of these objects to look for tails or comae, and we visually inspected the remaining asteroids. Our activity detection pipeline highlighted a faint anti-solar tail-like feature around 2001 NL19 (279870) observed on 2018 November 07, six months after perihelion. This is consistent with cometary activity but additional observations of this object will be needed during its next perihelion to investigate its potential MBC status. If it is active our survey yields a detection rate of $\sim$1:300, which is higher than previous similar surveys, supporting the idea of dynamical clustering of MBCs. If not, it is consistent with previously estimated abundance rates of MBCs in the OMB (, Comment: 13 pages, 9 figures, accepted for publication in MNRAS

The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 minutes was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement ($\beta$) was possible. In the years prior to impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos. Here we report the change in the orbital period of Dimorphos as a result of the DART kinetic impact to be -33.0 +/- 1.0 (3$\sigma$) minutes. Using new Earth-based lightcurve and radar observations, two independent approaches determined identical values for the change in the orbital period. This large orbit period change suggests that ejecta contributed a significant amount of momentum to the asteroid beyond what the DART spacecraft carried., Comment: Accepted by Nature

Between 2010 and 2017 we have collected new optical and radar observations of the potentially hazardous asteroid (2102)~Tantalus from the ESO NTT and Danish telescopes at the La Silla Observatory and from the Arecibo planetary radar. The object appears to be nearly spherical, showing a low amplitude light-curve variation and limited large-scale features in the radar images. The spin-state is difficult to constrain with the available data; including a certain light-curve subset significantly changes the spin-state estimates, and the uncertainties on period determination are significant. Constraining any change in rotation rate was not possible, despite decades of observations. The convex lightcurve-inversion model, with rotational pole at ${\lambda}=210{\pm}41${\deg} and ${\beta}=-30{\pm}35${\deg}, is more flattened than the two models reconstructed by including radar observations: with prograde (${\lambda}=36{\pm}23${\deg}, ${\beta}=30{\pm}15${\deg}), and with retrograde rotation mode (${\lambda}=180{\pm}24${\deg}, ${\beta}=-30{\pm}16${\deg}). Using data from WISE we were able to determine that the prograde model produces the best agreement in size determination between radar and thermophysical modelling. Radar measurements indicate possible variation in surface properties, suggesting one side might have lower radar albedo and be rougher at centimetre-to-decimetre scale than the other. However, further observations are needed to confirm this. Thermophysical analysis indicates a surface covered in fine-grained regolith, consistent with radar albedo and polarisation ratio measurements. Finally, geophysical investigation of the spin-stability of Tantalus shows that it could be exceeding its critical spin-rate via cohesive forces., Comment: Main paper: 14 pages and 12 figure, Appendix: 13 pages and 12 figues

Images of short period comets returned from spacecraft have been the most valuable sources of information on their nucleus shapes and surface features to date. While there is no doubt that in situ missions are the optimal way to study individual comets in detail, ground-based nucleus observations are a much more practical means of gaining insights into the physical properties of the population as a whole. Even with relatively sparse lightcurve coverage we can extract estimates of their rotation periods, and determine their phase functions. Using precisely calibrated photometry spanning decades, Kokotanekova et al. [1] identified a correlation between increasing linear phase function slope and geometric albedo for 14 Jupiter-family comet (JFC) nuclei. It can be interpreted as a surface evolution from rough, unprocessed surfaces to smooth, eroded nuclei [2]. These results illustrate the significance of long term ground-based monitoring, with exciting implications for future study of small body surface evolution. In this work, we seek to extend the possible applications of these JFC lightcurves to produce a convex model of a comet nucleus. The overall shape of a body has a much larger effect on its rotational lightcurve than any fluctuations in albedo or light scattering properties across the surface [3,4]. As such, it is possible to extract information about the shape of a small body from its lightcurves alone. The technique of convex lightcurve inversion is routinely used to produce asteroid shape models from their ground-based lightcurves [5,6]. This procedure takes as input lightcurves that cover a wide range of observing geometries (solar phase angle, sub-observer latitude), and uses a linear-exponential solar phase function with combined Lommel-Seeliger and Lambertian light scattering models to create a convex hull representing the object's overall shape - this has been compared to the true shape of the object being "gift-wrapped". To date, this method has been used to produce only one convex model of a comet nucleus. This was the target of the Rosetta mission, comet 67P/Churyumov-Gerasimenko [7]. The procedure mathematically cannot recreate concave features, however the presence of substantial flat regions on the model of 67P masked large concavities, later identified as the slim neck that separates the two lobes of the bilobate shape. Physical considerations regarding the criteria for stability of any shape model may also be used to infer bilobate shapes, given that it is unlikely that single-lobed objects with extremely elongated axis ratios (a/b > 2.3) would have formed naturally [8,9]. Motivated by the relative success of the lightcurve inversion at revealing the physical properties of 67P from limited ground-based observations, we apply this shape modelling procedure to comet 162P/Siding-Spring. R-band lightcurves for this object have been collected between 2007 and 2018, at phase angles in range 0.4°-12°. According to the surface evolution hypothesis, 162P is an example of a dynamically "old", evolved JFC. It has a shallow phase function slope of (0.039±0.002) mag deg-1, a low geometric albedo pR = (2.2±0.3)% - one of the darkest surfaces of all studied comets - and is a slow rotator with a synodic period of (32.853±0.002)h [2]. This is in contrast with comet 67P, which has a high albedo and steeper phase function slope [10], characteristic of what is believed to be a dynamically younger, less eroded surface [11]. The observing geometries for comets are much more limited than for asteroids: the best technique for detecting the bare nucleus without coma contamination is to observe at heliocentric distances >3 au, where the comet is far enough from the Sun that water ice is no longer expected to sublimate. This typically restricts phase angle coverage to Given the limited observing geometries, using the convexinv software by Ďurech et al. [12] we have found so far that the best physical model for the 162P lightcurves results from treating them as calibrated rather than relative, which requires the additional steps of using distance-corrected magnitudes and fitting a phase function to the light scattering model. Our preliminary convex shape model is shown in Figure 1, with axial ratios a/b = 1.50 and b/c = 2.07 (where c ≤ b ≤ a are the lengths of the principal axes of inertia). The model produces artificial lightcurves from which we obtain a linear fit to the phase function after correcting for rotation. We will present the final results from this analysis at the meeting, having finalised the procedure and tested the robustness of the solution. Figure 1: Preliminary convex shape model for comet 162P from ground-based lightcurves. The z-axis is aligned with the spin axis. Top row shows the views along positive z, y, z; bottom row shows views along negative z, y, x. References: [1] Kokotanekova et al. 2017, MNRAS 471 2974 [2] Kokotanekova et al. 2018, MNRAS 479 4665 [3] Karttunen H. 1989, A&A 208(1-2), 314-319 [4] Kartunnen H. & Bowell E. 1989, A&A 208(1-2) 320-326 [5] Kaasalainen M. & Torppa J. 2001, Icarus 422(2) L39-L42 [6] Kaasalainen et al. 2001, Icarus 153(1) 24-36 [7] Lowry et al. 2012, A&A 548 A12 [8] McNeill et al. 2018, AJ 156(6) 282 [9] Jeans J. 1919, Problems of cosmogony and stellar dynamics [10] Fornasier S. et al. 2015, A&A 583 A30 [11] Vincent J-B. et al. 2017, MNRAS 469 S329–S338 [12] Ďurech et al. 2010, A&A 513 A46

Near-Earth asteroids are the small rocky bodies orbiting the Sun in the vicinity of Earth's orbit. They are remnants of the planetesimals formed in the young Solar System, which repeatedly collided and underwent disruption. They form loosely-bound aggregates dubbed 'rubble piles'. Their dynamical and physical evolution is expected to be affected by a nongravitational torque called the YORP effect.\ud \ud The YORP effect is a torque due to the anisotropic emission of thermal photons on minor bodies in the Solar System. For small asteroids the radiation recoil torques can systematically modify rotational rates or shift spin axis orientations (Rubincam, 2000). The effect is crucial to understanding the dynamical and physical evolution of near-Earth asteroids, like the alignment of spin-axes (Slivan, 2002), the peculiar spin-top shapes observed for a few targets (Ostro et al., 2006; Scheeres et al., 2006), or rotational fission and evolution of asteroid binaries (Walsh et al., 2008; Pravec et al., 2010; Jacobson and Scheeres, 2011; Jacobson et al., 2016). The first direct detection of the asteroidal YORP effect on asteroid (54509) 2000 PH5 was possible thanks to the combination of radar and photometric lightcurve observations (Lowry et al., 2007; Taylor et al., 2007). Since then, YORP spin-up has also been detected on several other asteroids. However, the sample is still very small, and further observational data is needed to refine the YORP theories.\ud \ud The asteroids (1917) Cuyo and (85990) 1999 JV6, discussed here, were selected from a sample of nearly 40 YORP-detection candidates that were monitored photometrically, and in infra-red, through an ESO Large Programme (ESO LP) led by S. C. Lowry at the ESO New Technology Telescope and Very Large Telescope telescopes, and at other facilities with associated programmes.\ud \ud The ESO LP has been used to acquire photometric lightcurves of the asteroid (1917) Cuyo spanning the period between 2010 and 2013, which, combined with the 1989-2008 archive lightcurves, should provide a large enough time-base to constrain a possible YORP strength. However, the distribution of observations in time results in effectively having observations from just two epochs. This produces potential YORP values in the range of ?0.7 × 10?8 rad/d² (radians per day squared) and 1.5 × 10?8 rad/d². The rotation pole of the object is most likely located at l = 46°, b = -62°. The sidereal period was refined relative to earlier lightcurve estimates, to be (2.6897642 ± 0.0000035) h (hours). The shape of the object suggests the presence of an 'equatorial bulge', typical for an evolved system close to shedding mass due to fast rotation.\ud \ud For asteroid (85990) 1999 JV6, the data in the ESO LP span the period between 2007 and 2016. Additionally, the author has secured radar spectra and imaging observations with Arecibo and Goldstone planetary radars. Having radar observations permitted additional constraints on the shape and spin-state, but YORP spin-up was not detected. The asteroid is shown to have a bi-lobed shape, likely a result of two ellipsoidal components collapsing onto each other. The smaller lobe is close to spherical and has diameters (345 ± 9) m, (281 ± 8) m and (291 ± 9)m, and the larger is more elongated, with (580 ± 10) m, (322 ± 5) m and (332 ± 7) m. The rotation pole resides at negative latitudes in a circle of a 10° radius, close to the southern pole of the celestial sphere. The refined sidereal rotation period is (6.536787 ± 0.000006) h. No YORP-induced change in period was detected using the phase offset measurement using the radar model, however the global lightcurve-only analysis shows the object could be experiencing a spin-up of up to 7 × 10?8 rad/d².\ud \ud The shapes and spin-states developed here were used in further studies, beyond the scope of this thesis. Combined with the infra red observations the outcome of this work was used for thermophysical analysis by ESO LP collaborator B. Rozitis to constrain physical properties of both targets. The shape and rotation state of (1917) Cuyo can be used to investigate cohesive forces as a way to explain why some targets survive rotation rates faster than the fission limit. The detection of non-gravitational acceleration in the orbital motion of the asteroid (85990) 1999 JV6 combined with thermophysical modelling suggest a low, cometary-like density.\ud \ud The shape modelling and spin-state analysis tools were also applied to a Jupiter family comet, and the Rosetta mission target, 67P/Churyumov Gerasimenko. The author contributed to the confirmation of the seminal measurement of spin-rate change between previous perihelion approach and the arrival of Rosetta (Mottola et al., 2014, incl. A. Rozek). The detected 20 min decrease in the sidereal period, from ?12.7 h to ?12.4 h, was later linked to cometary activity (Keller et al., 2015b; Bertaux, 2015). Tools were also developed to assess the mean insolation of the comet’s surface, useful in calculations of nucleus dust production rates (Guilbert-Lepoutre et al., 2014, incl. A. Rozek), establish jet-activity source regions on the surface of the nucleus (Lara et al., 2015; Lin et al., 2015, 2016, incl. A. Rozek), and calibrate ground-based photometry using the spacecraft shape model (Snodgrass et al., 2016, incl. A. Rozek).