Answer : 1. "ESA"
Explanation :

Solution: Scientists have detected a faint green glow in the Martian night sky that can be seen with our human eyes. The European Space Agency (ESA)'s ExoMars Trace Gas Orbiter mission orbiting Mars observed the Martian night sky filled with light across the optical spectrum. According to scientists, the light in the polar regions is so bright that human explorers are likely to see it if the night sky is free of clouds.