Postcards from the Universe: Blues for the Red Planet

Dr. Paul Abel describes his telescopic views of Mars from Leicester, in the first of a series of blog posts called “Postcards from the Universe”

The skies of Leicester are somewhat hazy in the early hours this morning. It’s 3am and I’m in my observatory at home drinking my 5th cup of coffee. Not for the first time I’m starting to wonder if I’m now immune to the effects of caffeine. I’m waiting for the planet Mars to climb above the rooftops – it’s still quite warm and I am reminded of a few years ago when Pete Lawrence and I made the journey to the Lowell Observatory Flagstaff where we had access to the splendid 24 inch Clark refractor. The weather in Arizona that week was stormy with powerful thunderstorms but in the end we did get two clear nights. I remember seeing the shimmering disk of Mars through Lowell’s telescope – the polar ice cap glinting in the sunlight, the vast dark tracks Lowell once thought was evidence of a brilliant Martian civilisation.

Our understanding of Mars has gone through many revolutions. As telescopes became more powerful and the optics better produced, Lowell’s Canal network was shown to be an illusion. The idea that there might be life on Mars didn’t vanish with canals though- by the time of the 1950s it was thought that the dark patches visible on the surface might be due to some form of lowly planet life. The first spacecraft which successfully made the long voyage to the Red Planet revealed a barren world of craters and featureless deserts- it was assumed that Mars was a dead world rather like to the Moon with nothing much of interest on the surface. Astronomers begun to sing ‘Blues for the Red Planet” (that’s a Carl Sagan quote, not mine sadly)

Science is an ongoing narrative, constantly refining and improving itself and further robotic explorers revealed a world of volcanoes, ancient river beds and dynamic polar caps. Our own University has been involved in the exploration of Mars – John Bridges and co have been involved in the Mars Science Laboratory and ExoMars missions trying to answer determine if life might have once existed on the planet long ago when it was warmer and wetter. Once more, it is reasonable to suggest that some form of very primitive life might exist on Mars, and as the planet finally clears the roof tops I wonder what Mars would have looked like in our night skies millions of years ago.

The two drawings here show the view of Mars I had that evening. Of course, modern astronomers don’t draw at the telescope any more- they haven’t done that since the early 20th century. First photography replaced the pencils, and today we use CCDs and cameras to capture these celestial photons. I’m often asked why I don’t use cameras like the rest of the amateur astronomers. The first reason is due to my somewhat limited technological skills as anyone who has patiently waited for me to get the computer to talk to the projector in Lecture Theatre A will attest to.

The second point is slightly more abstract- I am a theoretical physicist and in my case the Universe (well, black holes and quantum fields) are modelled by mathematics (well, often divergent integrals), and while I might experiment with different integration techniques or spend an entire afternoon looking for a minus sign, it’s not quite the same as an experimental procedure. This aspect of amateur astronomy keeps me in touch with the experimental side of physics which is I think essential.

Back to the two drawings here – they show a number of features. In a telescope, south is at the top and you can see the bright southern polar cap which has now started to fragment and break up. It’s summer in the southern hemisphere of Mars and as the cap heats up, it shrinks and returns volatiles back into the Martian atmosphere. The darker markings you can see are (to the left) Terra Sirenum (left of centre) and Terra Cimmeria (right of centre). Cimmeria is of particular interest due to the recent discoveries of gullies which may be the result of recent flowing water on the planet.

Mars isn’t going to stay in the morning sky, as we get closer to it it will become larger and brighter and become well placed in our evening skies from September onwards. On 13th October Mars will be at opposition- in other words Mars, the earth and the sun will lie on a straight line with earth in the middle. The planet will be a brilliant object in the night skies and if you have access to a telescope, you should take a look at it and see what Mars looks for yourselves.  For full details of how to find Mars in the sky from your location, use this web resource (In The Sky).