Fig. 1: Image description (alt text) example for different scientific images.

On the left, a giant hole in the ground at the top of the Nyiragongo volcano (Democratic Republic of Congo) containing a black lava lake that is approximately 200 metres in diameter. There are whitish gas plumes rising from holes in the semi-solid surface of the lake. The holes are glowing orange. There are six tents only a few hundreds of metres away from the lava lake. On the right, Vero CCL-81 cells used in a fluorescence-based assay designed to measure neutralisation of a reporter SARS-CoV-2 by antibodies from patient specimens. After reporter viral infection, the cells turned green in the absence of serum (top panel). In contrast, incubation of the reporter virus with COVID-19 patient serum decreased the number of fluorescent cells (bottom panel)¹⁴. Scale bar, 100 μm. On the bottom, selfie taken by the NASA’s Curiosity rover on the 11^th October 2019 in the Glen Etive location (Gale Crater, Mars) showing the rover and two holes “Glen Etive 1” and “Glen Etive 2” drilled alongside it (Credits: NASA/JPL-Caltech).