Observation of meteors from space with the Mini-EUSO detector on board the International Space Station

¹ INAF – Astrophysical Observatory of Turin, Via Osservatorio 20, 10025 Pino Torinese, Italy
e-mail: dario.barghini@inaf.it
² Department of Physics – University of Turin, Via Pietro Giuria 1, 10125 Turin, Italy
³ INFN – Section of Turin, Via Pietro Giuria 1, 10125 Turin, Italy
⁴ Université Paris Cité, CNRS, Astroparticule et Cosmologie, 10 Rue Alice Domon et Léonie Duquet, 75013 Paris, France
⁵ Faculty of Physics – Lomonosov Moscow State University, 1(2), Leninskie gory, 119991 Moscow, Russia
⁶ Skobeltsyn Institute of Nuclear Physics – Lomonosov Moscow State University, 1(2), Leninskie gory, 119991 Moscow, Russia
⁷ INFN – Section of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
⁸ RIKEN, 2-1 Hirosawa Wako, 351-0198 Saitama, Japan
⁹ KTH Royal Institute of Technology, Brinellv ${\bar C_{xy}}(t)$ g ¨ en 8, 114 28 Stockholm, Sweden
¹⁰ Department of Physics, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
¹¹ Technical University of Munich, Arcisstraße 21, 80333 Munich, Germany
¹² S.P. Korolev Rocket and Space Corporation Energia, Lenin str., 4a Korolev, 141070 Moscow area, Russia
¹³ ASI, Italian Space Agency, Via del Politecnico, 00133 Rome, Italy
¹⁴ Omega, Ecole Polytechnique, CNRS/IN2P3, Route de Saclay, 91120 Palaiseau, France
¹⁵ Department of Astronomy and Astrophysics, The University of Chicago, 5640 S. Ellis Avenue, 60637 Chicago IL, USA
¹⁶ INFN – National Laboratories of Frascati, Via Enrico Fermi 54, 00044 Frascati, Italy
¹⁷ Arpa Piemonte, via Pio VII, 9, 10135 Turin, Italy
¹⁸ Department of Physics, Konan University, 8 Chome-9-1 Okamoto, Higashinada Ward Kobe, 658-8501 Hyogo, Japan
¹⁹ Department of Physics, Colorado School of Mines, 1523 Illinois Street, 80401 Golden CO, USA
²⁰ National Centre for Nuclear Research, ul. Pasteura 7, 02-093 Warszawa, Poland
²¹ Faculty of Physics, University of Warsaw, Ludwika Pasteura 5, 02-093 Warsaw, Poland
e-mail: lech-wiktor.piotrowski@fuw.edu.pl
²² Stefan Batory Academy of Applied Sciences, Stefana Batorego 64C, 96-100 Skierniewice, Poland

Received: 15 January 2024
Accepted: 14 May 2024

Abstract

Context. Observations of meteors in the Earth’s atmosphere offer a unique tool for determining the flux of meteoroids that are too small to be detected by direct telescopic observations. Although these objects are routinely observed from ground-based facilities, such as meteor and fireball networks, space-based instruments come with notable advantages and have the potential to achieve a broad and uniform exposure.

Aims. In this paper, we describe the first observations of meteor events with Mini-EUSO, a very wide field-of-view telescope launched in August 2019 from the Baikonur cosmodrome and installed on board the Russian Zvezda module of the International Space Station. Mini-EUSO can map the night-time Earth in the near-UV range (290-130 nm) with a field of view equal to 44° × 44° and a spatial resolution of about 4.7 km at an altitude of 100 km from the ground. The detector saves triggered transient phenomena with a sampling frequency of 2.5 µs and 320 µs, as well as a continuous acquisition at 40.96 ms scale that is suitable for meteor observations.

Methods. We designed two dedicated and complementary trigger methods, together with an analysis pipeline able to estimate the main physical parameters of the observed population of meteors, such as the duration, horizontal speed, azimuth, and absolute magnitude. To compute the absolute flux of meteors from Mini-EUSO observations, we implemented a simulation framework able to estimate the detection efficiency as a function of the meteor magnitude and the background illumination conditions.

Results. The instrument detected 24 thousand meteors within the first 40 data-taking sessions from November 2019 to August 2021, for a total observation time of approximately 6 days with a limiting absolute magnitude of +6. Our estimation of the absolute flux density of meteoroids in the range of mass between 10⁻⁵ kg to 10⁻¹ kg was found to be comparable to other results available in the literature.

Conclusions. The results of this work prove the potential for space-based observations to increase the statistics of meteor observations achievable with instruments operating on the ground. The slope of the mass distribution of meteoroids sampled with Mini-EUSO suggests a mass index of either s = 2.09 ± 0.02 or s = 2.31 ± 0.03, according to two different methodologies for the computation of the pre-atmospheric mass starting from the luminosity of each event.