Ordinary Meeting, 2006 January 25


Cosmology: Into the Unknown

[talk summary from CJL to be inserted]

After the applause for Mr Lintott's talk, the President invited the evening's final speaker, Mr Doug Ellison, to give an update on the activities of NASA's Spirit Rover on the surface of Mars.

The Spirit Mars Rover: An Update

After thanking Hazel Collett for inviting him to the meeting, Douglas Ellison began an update to the status of the Mars Exploration Rover Spirit showing a cartoon that compared Spirit to the 'Energiser Bunny', explaining that despite being designed for only 90 Martian days of operation, Spirit was still alive and conducting science after 734 sols.

As part of NASA's Mars Exploration pathway of 'Follow the Water' - Spirit was launched in the summer of 2003 toward Gusev Crater, a 150km wide feature that appeared to have acted as a lake in the distant Martian geological past, so in essence, Spirit landed on an ancient lake bed.

The speaker apologised to those who had not seen his talk in April 2005, but for brevity, and using what he called a 'road trip movie' of frames taken by Spirit's front hazard avoidance camera - he mentioned brief highlights of the first 400 days of Spirit's traverse from its landing site, to a nearby crater called 'Bonneville' and then 2.5km across the surface toward a set of hills called 'Columbia' and it's tallest peak named after the commander of the lost Space Shuttle Crew - Rick Husband.

Spirit found little evidence of the ancient water in which it went in search of, until arriving at the foot of 'West Spur' which juts out from Husband Hill, however low on power and with struggling mobility, Spirit slowly crawled its way to the top of West Spur, and by Sol 400 had reach a outcropping of rock called 'Larry's Lookout' where instruments showed the rocks to contain minerals that usually form in water, particularly Hematite and Goethite. At this point, an astonishing series of wind gusts cleared Spirit of much of the dust that had covered its solar arrays. From about 800 Watt Hours of power at landing, power levers dipped as low as 300 Watt hours before these cleaning events returned power to more than 700 Watt Hours.

The speaker then walked the audience through the drive toward the summit of Husband Hill alternating between the stunning panoramas that Spirit took at several points en route, and short driving movies that linked them.

By Sol 530, Spirit had reached the Summit of Husband Hill, and Mr Ellison tried to demonstrate the resolution of the panorama that was taken by demonstrating that it would require 32 of the largest computer displays available, or 3 Imax screens to show it at its full resolution.

To laughter from the audience, the speaker then suggested that Spirit might form member 0001 of the 'Mars Astronomy Association' and would be an active participant in the Lunar, Deep Sky and Meteor sections, showing images that had been taken with the high resolution 'Pancam' of Phobos and Deimos, the Orion Nebula, and possible Meteor Trails by virtue of the large power surplus that allowed Spirit to operate on fully charged batteries late into the night.

The audience then donned the anaglyph glasses with which they had been issued, and were shown stereo images that showed the 'Hillary' outcrop at the absolute summit of Husband Hill, and a stereo image generated from orbital imagery that showed the planned route from the summit to an large raised, flat, light coloured feature that scientists had called 'Home Plate' half a mile south of the Summit, and thru a series of route maps, the speaker showed the route Spirit had taken to a point approximately half way to Home Plate, finishing with imagery taken at 5:19 am on the morning of the meeting.

The speaker then highlighted the longevity and scientific productivity of Spirit by comparing the design specification of 90 Sols, 600 metres driving and 1 full panorama, to its achievements at the time of the talk of 734 sols, 6096 metres, and 12 panoramas. He then took a map of central London, and by way of transposing the route that Spirit had driven demonstrated that it had, by pure chance, covered a route that would have taken it from the former meeting venue of the English Heritage Lecture theatre, to the new venue at King's College.

Before concluding with a beautiful image of a Martian sunset and the strange fact that terrestrial skies are blue with red sunsets whilst Martian skies are red with blue sunsets, Mr Ellison reminded the audience that Opportunity, Spirits twin rover, had been operating for just as long and even been even more productive scientifically on the other side of the planet, and hoped he would see many of the members at the Out of London meeting in April when he would be talking about Eagle, Endurance and Erebus, Opportunity at Meridiani Planum.

After the applause for Mr Ellison's enthralling account, the President adjourned the meeting until March 22.


Doug Ellison, Chris Lintott and Martin Mobberley.

© 2006 Dominic Ford / The British Astronomical Association.






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