Observation of night-time emissions of the Earth in the near UV range from the International Space Station with the Mini-EUSO detector

Abstract

Mini-EUSO (Multiwavelength Imaging New Instrument for the Extreme Universe Space Observatory) is a telescope observing the Earth from the International Space Station since 2019. The instrument employs a Fresnel-lens optical system and a focal surface composed of 36 multi-anode photomultiplier tubes, 64 channels each, for a total of 2304 channels with single photon counting sensitivity. Mini-EUSO also contains two ancillary cameras to complement measurements in the near infrared and visible ranges. The scientific objectives of the mission range from the search for extensive air showers generated by Ultra-High Energy Cosmic Rays (UHECRs) with energies above 10${}^{21}$ eV, the search for nuclearites and Strange Quark Matter (SQM), up to the study of atmospheric phenomena such as Transient Luminous Events (TLEs), meteors and meteoroids. Mini-EUSO can map the night-time Earth in the near UV range (between 290-430 nm) with a spatial resolution of about 6.3 km (full field of view of 44°) and a maximum temporal resolution of 2.5 $\mu$s, observing our planet through a nadir-facing UV-transparent window in the Russian Zvezda module. The detector saves triggered transient phenomena with a sampling rate of 2.5 $\mu$s and 320 $\mu$s, as well as continuous acquisition at 40.96 ms scale. In this paper we discuss the detector response and the flat-fielding and calibration procedures. Using the 40.96 ms data, we present $\simeq$6.3 km resolution night-time Earth maps in the UV band, and report on various emissions of anthropogenic and natural origin. We measure ionospheric airglow emissions of dark moonless nights over the sea and ground, studying the effect of clouds, moonlight, and artificial (towns, boats) lights. In addition to paving the way forward for the study of long-term variations of natural and artificial light, we also estimate the observation live-time of future UHECR detectors.

49 pages, 27 figures, 1 table, published in Remote Sensing of Environment

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• Measurement of the cosmic-ray energy spectrum above $2.5\times 10^{18}$ eV using the Pierre Auger Observatory
• The TUS detector of extreme energy cosmic rays on board the Lomonosov satellite
• Mini-EUSO mission to study Earth UV emissions on board the ISS
• The integration and testing of the Mini-EUSO multi-level trigger system
• Science and mission status of EUSO-SPB2
• Secondary cameras onboard the Mini-EUSO experiment: Control Software and Calibration

Cited by in corpus (7)

• The EUSO-SPB2 Fluorescence Telescope for the Detection of Ultra-High Energy Cosmic Rays
• Developments and results in the context of the JEM-EUSO program obtained with the ESAF Simulation and Analysis Framework
• Study of multiple ring ELVES with the Mini-EUSO telescope on-board the International Space Station
• Analysis of EAS-like events detected by the Mini-EUSO telescope
• Implications of Mini-EUSO measurements for a space-based observation of UHECRs
• Machine Learning for Mini-EUSO Telescope Data Analysis
• Neural Network Based Approach to Recognition of Meteor Tracks in the Mini-EUSO Telescope Data