# Early Results from TUS, the First Orbital Detector of Extreme Energy Cosmic Rays

## TL;DR

TUS is the first orbital detector designed to observe extreme energy cosmic rays by capturing UV fluorescence and Cherenkov radiation from air showers, providing initial insights into atmospheric UV phenomena from space.

## Contribution

This paper presents the first operational results of TUS, the pioneering orbital detector for EECRs, highlighting its design and initial event detections from space.

## Key findings

- Detection of diverse UV atmospheric phenomena
- Initial identification of air shower events
- Rich variety of UV radiation observed from orbit

## Abstract

TUS is the world's first orbital detector of extreme energy cosmic rays (EECRs), which operates as a part of the scientific payload of the Lomonosov satellite since May 19, 2016. TUS employs the nocturnal atmosphere of the Earth to register ultraviolet (UV) fluorescence and Cherenkov radiation from extensive air showers generated by EECRs as well as UV radiation from lightning strikes and transient luminous events, micro-meteors and space debris. The first months of its operation in orbit have demonstrated an unexpectedly rich variety of UV radiation in the atmosphere. We briefly review the design of TUS and present a few examples of events recorded in a mode dedicated to registering EECRs.