Do not get worried that the Mars rover, Curiosity, has found giant spiders on the Red Planet or that David Bowie was right when he produced his album, “Spider From Mars”. Instead, it refers to a pretty interesting step forward in the search for past life on Mars. What Curiosity has found has been described by NASA scientists as “spiderwebs”. These refer to patterns in the surface indicating that rivers and areas of water used to flow across the surface of Mars. And where there is water, there may also have been life of a sort.
What the rover has found are being described as “boxwork” features. The patterns on the surface are a collection of ridges which are left when water dries up. The exciting part of this is that there may be the remains or fossils of some early and or simple lifeforms in the same area. The patterns of ridges have been measured up to 12 miles across. Similar patterns have been found on Earth and also signify where water once flowed. The spiderweb analogy has come from images taken from orbit by satellites.
There is a geological feature on Mars which has also been labelled the “Spider from Mars”. However, this feature is caused by icy deposits of carbon dioxide, very different from what we are discussing here. The thinking behind how this area could produce evidence of past life relies on the belief that there were once subsurface lakes of water, which may have been suited to creating life on the planet. Time will tell.
John Pullen 