Mini-EUSO is the first mission of the JEM-EUSO program on board the International Space
Station. It was launched in August 2019 and it is operating since October 2019 being located in
the Russian section (Zvezda module) of the station and viewing our planet from a nadir-facing
UV-transparent window. The instrument is based on the concept of the original JEM-EUSO
mission and consists of an optical system employing two Fresnel lenses of 25 cm each 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 and an overall field of view of 44×44 degrees. Mini-EUSO can map the night-time Earth in the near UV range (predominantly between 290 nm and 430 nm), with a spatial resolution of about 6.3 km and different temporal resolutions of 2.5 𝜇s, 320 𝜇s and 41 ms. Mini-EUSO observations are extremely important to better assess the potential of a space-based detector in studying Ultra-High Energy Cosmic Rays (UHECRs) such as K-EUSO and POEMMA. In this contribution we focus the attention on the results of the UV measurements and we place them in the context of UHECR observations from space, namely the estimation of exposure.