Whilst roving about Mars, Curiosity has slowly but surely racked up evidence for a past Mars that was warm, wet, and possibly habitable.
John P. Grotzinger of Caltech, the project scientist for the mission, reported at a news conference on Monday that the rover's yearlong trek to Mount Sharp provided strong new evidence that Gale Crater had large lakes, rivers and deltas, on and off, for millions to tens of millions of years. The geology shows that even when the surface water dried up, plenty of water would have remained underground, he said.
Moreover, the team concluded, numerous deltalike and lakelike formations detected by orbiting satellites are almost certainly the dried remains of substantial ancient lakes and deltas. None of this proves that life existed on the planet, but the case for an early Mars that was ripe and ready for life has grown stronger.
"As a science team, Mars is looking very attractive to us as a habitable planet," Dr. Grotzinger said in an interview. "Not just sections of Gale Crater and not just a handful of locations, but at different times around the globe."
See also the interactive 28 Months on Mars.
Update: And right on cue, Curiosity has recorded a two-month-long methane burst on Mars. One explanation for the methane is that it's a waste product of living organisms.
The presence of methane is significant because the gas cannot exist for long. Calculations indicate that sunlight and chemical reactions in the Martian atmosphere would break up the molecules within a few hundred years, so any methane there now must have been created recently.
It could have been created by a geological process known as serpentinization, which requires both heat and liquid water. Or it could be a product of life in the form of microbes known as methanogens, which release methane as a waste product.
Even if the explanation for the methane turns out to be geological, the hydrothermal systems would still be prime locations to search for signs of life.
If there wasn't life on Mars before, there might be now. Before NASA sent Curiosity to Mars, it was thoroughly cleaned of all traces of contaminants. But swabs of rover's surfaces taken before it was sent to Mars have revealed 377 different strains of bacteria that potentially could have made the trip. Some of them may have even survived.
A study that identified 377 strains found that a surprising number resist extreme temperatures and damage caused by ultraviolet-C radiation, the most potentially harmful type. The results, presented today at the annual meeting of the American Society for Microbiology, are a first step towards elucidating how certain bacteria might survive decontamination and space flight.
Earlier this month, the Curiosity rover photographed a dry stream bed on the surface of Mars.
That's the Mars river bed on the left and an Earth river bed on the right. Note the flat smooth rocks in the Mars pic. Pretty cool.
From Our City, Our Story, the story of a Rockford, Illinois gear factory that made all of the gears for the Mars Curiosity rover.
What might be more remarkable than creating crucial equipment destined for Mars? For a second time? Well, creating a thriving motivated company culture with a team of career employees -- the kind who lie in bed at night thinking, "what can I do in the morning when I get there?" The kind who take on responsibility, impose their own high standards and like Amy Sovina, have the "mindset something I touched is now on the surface of Mars."
I would love to have seen a live feed of these gear shop employees watching the landing.
The main imaging cameras on the Mars Curiosity rover have only 2-megapixel sensors with 8 GB of flash memory -- compare that to a maxed-out iPhone 4S with an 8-megapixel sensor and 64 GB of flash memory (not to mention 30-fps 1080p video). Planning timeframes and communications bandwidth contributed to the chosen camera size.
'There's a popular belief that projects like this are going to be very advanced but there are things that mitigate against that. These designs were proposed in 2004, and you don't get to propose one specification and then go off and develop something else. 2MP with 8GB of flash [memory] didn't sound too bad in 2004. But it doesn't compare well to what you get in an iPhone today.'
The cameras were also supposed to be outfitted with zoom lenses but that part of the project was scrapped.
The rest of you can have your Olympics, but the early August event I'm most looking forward to is the arrival on Mars of the Curiosity rover. But NASA has had some problems in the past delivering payloads to Mars, so this is going to be somewhat of a nail-biter. If you haven't seen it, Curiosity's Seven Minutes of Terror is well worth watching to see the logistical challenge of getting the rover down to the surface.
Curiosity will hopefully land on the surface on Aug 6 at about 1:30 am ET.