Keep an eye on Mars this week – low in the south west after sunset. The distinctly red Mars makes a triangle with somewhat dimmer Saturn and the bright star Spica. Mars is closing in on the other two – and will form part of a nearly perfect equilateral triangle with them on August 8. That’s just two days after the latest Mars rover is due to land on the red planet. It is planned that Curiosity will explore the 150km wide Gale crater for the next two years.
This crater was named in 1991 for the Australian banker and amateur astronomer Walter F Gale. Born in 1865, he built his own 7 inch telescope while still a teenager. Gale used this and subsequent telescopes to methodically search the sky each clear night. This paid off and over his lifetime he discovered seven comets, one (known as 1894 II) with a mere 3 inch telescope. He also discovered comet 34P/Gale in 1927. This Jupiter class comet was observed 11 years later, but has been lost ever since!
The rover is due to land near Aeolis Mons – which was known as Mount Sharp – at least to NASA.
This large peak in the middle of Gale crater was officially named Aeolis Mons in May of this year – following from the general name for the region “Aeolis.” The name “Mount Sharp” arose from the former NASA planetary scientist Robert Sharp and appears all over press releases from NASA about the mission. Unfortunately, the right to name planetary features is reserved by the International Astronomical Union, and they hadn’t called it Sharp!
With all the excitement about Curiosity we shouldn’t lose sight of the huge accomplishments of the two much smaller rovers that explored Mars from early 2004. The earlier rovers Spirit and Opportunity explored Mars for well over their planned lifespan, leading to a host of names of features. There are seven hills named for the crew of the space shuttle Columbia – although these names are all unofficial.
The rover Spirit was finally declared lost at the end of May last year – it had become stuck in sand in 2009 and was unable to free itself. It continued to transmit from its new stationary site into 2010, but the last communication was in March of that year. Its twin rover, Opportunity, located in a different part of Mars has continued functioning, travelling over 34 km in over 3000 Martian days. Most days the rover might travel 50 to 100 m and it parks up during the winter months to ensure that it gets enough sunlight to keep functioning. Some of its instruments are losing power, now taking weeks to make measurements that used to be completed in hours.
Rovers are supported by the fleet of orbiters around Mars. The European Space Agency has Mars Express ready to transmit signals from Curiosity and there are two NASA spacecraft – the Mars Reconnaissance Orbiter and Odyssey. The veteran spacecraft Odyssey, in orbit around Mars since 2001, was given a nudge last week to get it into just the right position to transmit data from Curiosity as it lands. So if you catch sight of Mars this week, just think of the flurry of activity underway; we can hope that Curiosity follows in the tracks of Spirit and Opportunity and outlasts its planned mission to the same extent.