Main results of the TUS experiment on board the Lomonosov satellite

TL;DR

The TUS experiment on the Lomonosov satellite was the first space-based effort to detect ultra-high-energy cosmic rays, recording various atmospheric phenomena and potential cosmic ray events, providing valuable insights for future orbital missions.

Contribution

This paper presents the first results from the TUS space-based detector, including data on atmospheric phenomena and potential cosmic ray events, advancing the development of future orbital UHECR detection missions.

Findings

Recorded nearly 90,000 events including lightning, meteors, and luminous phenomena.

Identified potential EAS candidates with energies around 1 ZeV, but likely of terrestrial origin.

Provided valuable data for future space-based cosmic ray detection efforts.

Abstract

The TUS detector was the first space-based mission aimed for ultra-high-energy cosmic ray (UHECR) measurements. The detector was designed to register the fluorescent signal of extensive air showers (EAS) developing in the night atmosphere of Earth in the UV range of 300-400 nm. TUS was launched on board the Lomonosov satellite in April, 2016 and operated till December, 2017. Almost 90 thousand events were recorded during the mission, among them lightning discharges, meteors, transient luminous events, polar lights and anthropogenic signals. Some puzzling bright UV flashes in a clear sky far from possible artificial sources were also registered. Besides this, a number of EAS candidates were found in the TUS database. The majority of candidates analysed so far were recorded above populated areas near airports or similar objects, and the energy of the signals corresponds to at least 1 ZeV if they were generated by an UHECR, which does not allow one to consider these events as UHECRs. We briefly present the main results of the TUS experiment and discuss its importance for the development of the future orbital missions.