This silent animation from the NASA site (21 meg) gives a good indication of the complexity of the mission. The robots landed on mars folded up into tetrehedral packages, with the landing on the planet facilitated with parachutes, jets and airbags.
Even more impressive is that the robots are still operational now (August 2008), although at the moment Spirit is not doing much, to conserve energy during the Martian winter. Updates can be read at the Mars Rovers mission page.
Meanwhile the Phoenix lander arrived on Mars in May this year to examine the polar ice (see Phoenix mission page).
Although there is a lot more to these missions than looking for signs of life, whenever the robots find clues about water or other things that may support life it makes lots of headlines. Finding life on other planets is a big deal, and lots of people are very interested.
Things got extra interesting over the last few days when this story appeared on 2nd August:
The White House is Briefed: Phoenix About to Announce "Potential For Life" on Mars (at universetoday.com, although the story may have originated elsewhere)
The gist of the story was that Phoenix had found something exciting, which although not proof of life was important enough that the White House was being briefed. This would have been an unusual thing for NASA to do, as most scientific results are released directly.
This causes a lot of excitement. However, the Phoenix lander has its own Twitter feed, where short little announcements are made, and questions answered. Amusingly, the Phoenix twitter entries are written as if from the robot itself. Shortly after the 'White House' story broke, these two items appeared on Twitter:
Heard about the recent news reports implying I may have found Martian life. Those reports are incorrect. 10:06 PM August 02, 2008
Reports claiming there was a White House briefing are also untrue and incorrect. 10:12 PM August 02, 2008
Then yesterday the announcement came that Phoenix had found perchlorate in the soil. Perchlorate is an oxidant and its presence is thought to make the possibility of life on Mars somewhat less likely. For example, see this CNN article:
Toxin in soil may mean no life on Mars.
Is this a big deal? I found this post on a forum from an anonymous, but apparently genuine, Phoenix mission insider:
For those of you that may care, this is a really big deal. I've worked on several NASA programs and am currently supporting the Phoenix mission. This is the key takeaway:
There are a lot of old, rich, powerful scientists, most of them atheists, that consider it one of their most important goals in life to discover life somewhere out there in space. This toxin discovery is a major frustration and embarrassment to these people, and it has implications for the future of the Orion program, which I also worked on, which is supposed to replace the shuttle program in a few years. They were going to make it so that Orion could take astronauts to Mars eventually, but this new discovery may put a damper on those plans.
NASA had a press briefing a couple of hours ago to discuss the perchlorate. I didn't catch the briefing but from Phoenix's Twitter comments it seems that NASA are playing down its significance at the moment:
Today's participants feel that presence of perchlorate is not a positive or negative for life on Mars; "it just changes the equation." 14 minutes ago
By changing the equation, they mean it describes a *different* potentially habitable environment - but not a greater or lesser probability. 12 minutes ago