Mars observations by English artist and astronomer Nathaniel Everett Green. In the summer of 1877, there was a favourable opposition of Mars, meaning that Mars was directly opposite the Sun, high in the sky at midnight, and as close to Earth as it could get. Green packed up his 13-inch telescope and travelled to Madeira, a Portuguese island west of the Straits of Gibraltar, hoping for better observing conditions. When he returned to England, he presented his Mars drawings to the Royal Astronomical Society. The drawings were later published in the Societys Memoirs in 1879.