In 1970 Hardy's first SF cover appeared on the then-new magazine Vision of Tomorrow. Another cover followed, then he was commissioned to paint a different planet each month, together with a one-page article about it which he wrote himself. This is the first one: Mercury.
Painted in gouache in 1972 for Challenge of the Stars with Patrick Moore, this shows the glare of the Sun eclipsed by a large rock – the only way to see its Zodiacal Light (a swarm of dust left behind from the origin of the Solar System). The blue Earth and Moon can be seen as a bright double star.
Mercury & Sun
Mercury and the Sun, three times bigger than we see it, from space. Mercury is cratered and very Moonlike, at least superficially. Digital, from Futures: 50 Years in Space.
In this digital image (Terragen and Photoshop) Hardy does not show the Sun's corona and Zodiacal Light. Instead he attempts to portray the intense glare and light on the surface of the inner planet.
Mercury is a tiny planet which is closest to the Sun. Its day side is hot enough to melt lead, while its dark side is one of the coldest places in the Solar System.