Current progress in the understanding of the physics of large bodies recorded by photographic and digital fireball networks Manuel Moreno-Ibáñez, Maria Gritsevich, Josep M. Trigo-Rodríguez & Esko Lyytinen

2 Observation: Fireball Networks Video Station a at Folgueroles (Spain) All Sky camera at Montsec Observatory (Spain) The new SLR observatory, Vaisala weather station and the 2Mpx all sky camera at Metsähovi Geodetic Research Station (Finland). (see poster Raja-Halli et al.) Scientific cooperation and data sharing between Fireball Networks: Spanish Meteor Network, Finnish Fireball Network, French Network, etc.

3 The equations of motion for a meteoroid entering the atmosphere projected onto the tangent and to the normal to the trajectory Variation of the mass 3 3 Extra equations 4 4 Use of dimensionless parameters Where index e indicates values at the entry of the atmosphere. h0 is the scale height (7.16 km) Atmospheric flight equations of motion 5 5 Initial conditions: Classical theory Dimensionless methodology

4 In this methodology we gather all the unknown values of the meteoroid’s atmosphere flight motion equations into two new variables (Stulov et al. 1995; Gritsevich, 2009): Ballistic CoefficientMass loss parameter Scaling laws and dimensionless variables (α and β are obtained using a weighted least-squared method combined with the fireball (h,v) data set.)

α and β classification 5 Values from Gritsevich 2009 and 2012

6 Derivation of other parameters Eq. [1] Ablation coefficient Entry mass Terminal mass

7 State-of-the-art I First large classification of fireballs and meteorites using α and β parameters for 143 objects from the Meteor Observation and Recovery Project (MORP, Canada) and 121 objects from the Prairie Network (PN) database. Constrains the percentage of kinetic energy emitted as light. Inclusion of meteor mass and velocity variations avoiding meteor bulk density, shape and initial mass. Discussion of methodology accuracy through the analysis of 4 meteorite atmospheric flights trajectories Gritsevich 2008 Gritsevich 2009 Gritsevich and Koschny 2011 Bouquet et al Suggests a satellite based detection system using this methodology. They also study the mean values for µ parameter.

8 Studies the efficiency of simplifications of the equations (1,2) to accurate describe the terminal height of fireballs and meteorites. Suggests the way of incorporate different atmospheric models in the dimensionless equations of motion. Using detailed height and atmospheric pressure probes to increase accuracy. Moreno-Ibáñez et al State-of-the-art II Lyytinen and Gritsevich 2016

9 Conclusions Parameters α and β show physical meaning and are potentially the basis of a new fireball and meteorite classification. Relevant meteor atmospheric flight parameters are easily derived from the main equations. The mathematical formulation is flexible enough so as to include different atmospheric models or real data provided by local weather stations. Simplifications of the equations are also possible, and the accuracy of their results have already been checked. We foresee the derivation of α, β terminal height and masses values for both, the Finnish and Spanish fireball networks, including atmospheric corrections. Future Work Determination of α and β parameters for meteor showers. Since they are originated by comets and asteroids, new clues about them could be derived.

10 Bouquet A. et al Planetary Space Science 103: (2014). Gritsevich M., Solar Syst. Res. 42, (2008). Gritsevich M., and Popelenskaya N.V., Doklady Phys. 53, (2008). Gritsevich M., Adv. Space Res (2009). Gritsevich, M., and Koschny, D., Icarus 212 (2), (2011). Gritsevich M. et al, Cosmic Research, 50(1), (2012). Halliday I. et al., Meteorit. Planet. Sci. 31, (1996). Lyytinen E., and Gritsevich M., Planet. Space Sci. 120, (2016). Moreno-Ibáñez M. et al., Icarus 250, (2015) Stulov V.P. et al., Aerodinamika bolidov, Nauka (1995). References Contact SPMN: