Mars opposition, images, canals and HG Wells
Mars imaged on the early morning of Wednesday 5 April 2014 by Anthony Wesley, one of Australia’s leading amateur astronomers, using his self-built 40-cm reflecting telescope. Image and copyright Anthony Wesley ©, all rights reserved. Used with permission
Today (8 April 2014) Mars is at opposition, that is, on the opposite side of the Earth to the Sun. Mars oppositions occur at roughly two year intervals when the Earth laps Mars in their perpetual race around the Sun. Due to the oval-shaped nature of the path of Mars around the Sun, the distance between the two planets is still lessening with the closest distance in six days’ time on 14 April 2014.
The current opposition is not a particularly favourable one as the distance between the planets is 0.621 AU (the distance of the Earth to the Sun). Compare this with the distance at the next favourable opposition on 27 July 2018 when Mars’ minimum distance will be 0.386 AU.
Anthony Wesley has produced some unbelievably clear images of Mars during this current opposition, such as the one above. A few years ago such an image could only have been produced by the Hubble Space Telescope or other space-based instruments. To produce such an image takes the right equipment, experience, great skill and considerable dedication. Anthony says of the image, “Syrtis Major is visible at lower right, and it will become more central over the next few days from here. The north polar cap is visible at top as well as a cloud-filled Hellas basin at bottom.”
Drawings of Mars by Walter Gale on 6 August 1892 at 12:30 am Sydney Mean Time (SMT) and 7 August at 11:15 pm EST. From the Illustrated Sydney News of 18 February 1893 p18
Before spacecraft and skilled amateurs with the right equipment, astronomers laboriously sketched the planet while waiting for momentary clear views through the Earth’s turbulent atmosphere. One of those who sketched the planet was the Sydney astronomer Walter Gale, two of whose images from the favourable Mars opposition of 1892 are shown above. The 154-km wide crater on Mars where the Mars Curiosity rover landed in 2012 is, of course, named after Gale.
North polar cap drawn at Lowell Observatory in 1905. From Percival Lowell’s book, Mars and its Canals. Courtesy Archives.org
American astronomer, Percival Lowell, set up an observatory specifically to study Mars in Flagstaff Arizona. Lowell, building on earlier observations at the favourable Mars opposition of 1877, was a great believer in Martian canals, that is, artificial water ways criss-crossing the planet. He thought that Mars was a parched and dying world whose inhabitants cooperated to create these mammoth canals to transport scarce water where it was most needed. Observing Mars by eye through a telescope is never easy and under the influence of his own ideas Lowell kept seeing numerous canals on the planet. Sadly, as can be seen in Anthony Wesley’s image at the top of this post and in spacecraft observations these canals do not exist and were just a trick of the eye. Still Lowell’s ideas led to great interest in the planet and helped to inspire the English writer HG Wells to write his famous book, the War of the Worlds.
Although the current opposition is not favourable, it is still worthwhile observing Mars with the unaided eye when it appears as a bright red object low in the eastern sky in the early evening or through a telescope at Sydney Observatory or elsewhere.