As of 1:31 am, August 6, 2012 (EDT), NASA and Jet Propulsion Lab has successfully landed the Curiosity Rover at the Gale Crater of Mars, as part of the Mars Science Laboratory mission.

This is an exciting moment for all of us and I'm sure many of you are burning with questions. Here is a place for you to submit all your questions regarding the mission, the rover, and Mars!

Update:

HiRISE camera from the Mars Reconnaissance Orbiter capturing Curiosity's descent

Thumbnail video of the descent from the Mars Descent Imager

Higher resolution photograph of Curiosity and its shadow, and Mount Sharp in the background.

FAQs (summarized from the official press release):

What is the purpose of the mission?

The four stated objectives are:

1. Assessing the biological potential by examining organic compounds - the "building blocks of life" - and searching for evidence of biologically relevant processes.

2. Uncovering the geological processes that formed the rocks and soil found on Mars, by studying the isotopical and mineralogical content of surface materials.

3. Investigate past and present habitability of Mars and the distribution and cycling of water and carbon dioxide.

4. Characterize the broad spectrum of surface radiation.

How was the mission site chosen?

In line with the mission objectives, Gale Crater is located at a low elevation, so past water would likely have pooled inside the crater, leaving behind evidence such as clay and sulfate minerals. The impact that created the crater also revealed many different layers, each of which will give clues on the planetary conditions at the time the material was deposited.

While previous landing sites must be chosen to safeguard the landing of the spacecraft, the new "sky crane" landing system allows for a much more accurate landing, which, combined with the mobility of the rover, meant that the mission site can be some distance from the landing site. The primary mission will focus on the lower elevations of the Gale Crater, with possible exploration in the higher slopes in future extended missions.

For a more detailed explanation see this thread.

Why is the "sky crane maneuver" to land the rover?

The Curiosity rover is the biggest - and more importantly, the heaviest - rover landed on Mars. It has a mass of 899 kg, compared to Spirit and Opportunity rovers, coming at 170 kg each. Prior strategies include landing the rover on legs, as the Viking and Phoenix landers did, and using airbags, as Spirit and Opportunity did, but the sheer size and weight of Curiosity means those two methods are not practical.

What happens to the descent stage after it lowers the rover?

The descent stage of the spacecraft, after releasing the rover, is programmed to crash at least 150 metres (likely twice that distance) away from the lander, towards the North pole of Mars, to avoid contamination of the mission site. Currently there is no telemetry data on it yet.

How long does it take for data to transmit one way between Earth and Mars?

On the day of landing, it takes approximately 13.8 minutes for data to be transmitted one way directly from Curiosity to Earth via the Deep Space Network, at a data rate of 160 - 800 bits per second. Much of the data can also be relayed via the Mars orbiters (Mars Reconnaissance Orbiter and Mars Odessy) at 2 megabits per second.

See this thread for more detail.

What are the differences between this rover and the previous ones landed on Mars?

For an overview of the scientific payload, see the Wikipedia page. This includes such valuable scientific instruments such as a laser-induced breakdown spectroscopy system, not found in the previous rovers. The gas chromatography system, quadrupole mass spectrometer and tuneable laser spectrometer are also part of the payload, not included in the Spirit and Opportunity rovers.

Discussion in comments here, and here.

Why were the first images of such low resolution?

The purpose for the first thumbnail images are to confirm that the Rover has landed and has operational capabilities. These images were taken from the Hazard Avoidance cameras (HazCams), rather than the main cameras. More images will be sent in the next window 15 hours after landing in order to pinpoint the landing site.

The Rover has a Mars Descent Imager capable of 1600 x 1200 video at 4 frames per second. The MastCam (with Bayer filter) is capable of 1600 x 1200 photographs, along with 720p video at 4 - 7 fps. The Hands Lens Imager is capable of the same image resolution for magnified or close-up images. The ChemCam can take 1024 x 1024 monochromatic images with telescopic capabilities. These cameras will be activated as part of the commissioning process with the rest of the scientific payload in the upcoming days/weeks.

Discussion in comments here, here, here, and here.

How is Curiosity powered?

The Rover contains a radioisotope thermoelectric power generator, powered by 4.8 kg of plutonium dioxide. It is designed to provide power for at least 14 years.

Discussion in comments.

When will Curiosity take its first drive? When will experimentation begin?

The first drive will take place more than one week after landing. It will take several weeks to a month to ensure that all systems are ready for science operations.

Discussion in comments here and here.