The Mars Science Laboratory "Curiosity" Has Landed on Mars!
The largest, most sophisticated robotic rover, Mars Science Laboratory (MSL), landed safely on Mars on the evening of August 5th, 2012. Touchdown was confirmed at 10:32 PM (Pacific Daylight Time) when the radio transmission from Mars' surface was received on Earth after traveling for 14 minutes at the speed of light. A few minutes later we received the first images.
The first one was a 64x64 pixel thumbnail and the second was 256x256 pixel version shown above on the left. It shows one of the wheels of MSL on the soil of Mars in the foreground at lower right of the frame. The horizon is seen at the upper half of the image along with a bit of dust still settling back down to the surface after being stirred up by the skycrane thrusters. The third and fourth images received back (64 pix thumbnail followed by its 256 pix full-size version above right) show the shadow of MSL on the surface of Mars. Whew!
These images are coming from the Hazcams located near the bottom of the rover. The first images were downsampled to smaller sizes and the dust covers were still on because the dust was still settling and NASA wanted to get pictures back to Earth ASAP even if it meant having to look through the dust cover. For the right image showing Curiosity's shadow, you can see a thin dark horizontal line. That looks like it could be the dark dunes at the base of the large central mountain of the crater (Mt Sharp) and there may be a hint of the profile of the mountain if you squint real hard but that was very uncertain from this picture.
A higher-resolution image (shown below) beamed back to Earth on the afternoon of August 6th with the dust cover off clearly confirms that yes, that we are looking at the dark dunes at the base of the mountain and Mt Sharp is clearly visible. Select the image to bring up the full size image. The image was taken at a different time of day so the shadow is a bit longer. Another thing to notice are all of the rounded pebbles. Are they rounded from the action of tumbling in liquid water in the past?
These images are still just from the Hazcams. Higher resolution and color images will be sent back when the main cameras on the mast are deployed later. The rover named "Curiosity" will spend at least one martian year (687 Earth days) determining if Mars ever had an environment able to support any kind of life by investigating the rocks and soil in Gale Crater. To learn more about Curiosity itself, go to the "Learn About Me: Curiosity" interactive.
One last image to share for this updated landing page is what Mars Reconnaissance Orbiter (MRO) saw as Curiosity parachuted to the surface yesterday evening. Note that while Curiosity was descended at a very fast rate, MRO itself was moving at a speed of 3 km/sec (over 6700 mph) and was about 200 km above MSL—darn good photography skill! Select the image to learn more about this image from the MSL website.
For a heart-warming short describing the feelings of the NASA team during and after the landing sequence view the following:
The video above, produced by Plumbline Pictures, is a collection of various NASA animation, telemetry data, onboard vehicle instrumentation, incident audio, and JPL footage, set to music and embellished with narration from NASA/JPL leaders. The filmmaker writes: "I was at JPL on this night, and I was compelled to produce something that approximated my experiences."
(This section written for the July 21, 2012 Night Sky column)
In the evening of August 5th, the Mars Science Laboratory, aka "Curiosity" will either land or crash on Mars. Curiosity is by far the largest rover, heck, even the largest craft of any type, to land on Mars and NASA will be using new techniques to get that rover onto Mars. The "7 Minutes of Terror" video explains about all the things that have to work absolutely correct for this thing to succeed and the list is pretty daunting. The seven minutes refer to the time when the craft is traveling through Mars' atmosphere to the touchdown (or fatal crash). Curiosity will hit the upper atmosphere at about 13,200 mph and the air friction is so intense that the spacecraft heats up to over 1600 deg C and possibly as high as 2100 deg C (3800 deg F). The craft's heat shield will prevent that heat from frying the rest of the rover but the heat will also ionize the surrounding air enough that radio communication between the Earth and the craft will not be possible. The seven minutes also refers to the additional time we'll have to wait to see if everything worked perfectly because of how long it takes the radio waves traveling at the speed of light to finally reach us here on Earth. On August 5th, the distance between Earth and Mars will be such that it will take fourteen minutes for the radio waves to travel from Mars to Earth.
Curiosity has been built smart enough (we hope) to take care of any anomalies during its descent by itself without any help from us. Remember that it takes seven minutes from hitting the top of the atmosphere to landing on the surface, so by the time we have received radio communication from Curiosity that it has reached the top of the atmosphere, it will have already been on the surface of Mars dead or alive for seven minutes. A number of things have to go right including: aerobraking through an atmosphere just 1% as thick as ours, withstanding all the heat generated from that aerobraking, small thrusters firing several times a second during the aerobraking phase to guide the package to stay within a very small window, deploying the largest supersonic parachute used on Mars when the craft is still moving at 1000 mph and surviving the 9 g's deceleration when the parachute deploys, ejecting the heat shield after parachute deployment so that the radar can locate its target landing area, separating from the parachute package when it is still falling at 200 mph and firing the skycrane's rockets with a radical horizontal thrust to avoid hitting the still-falling parachute package, lowering the rover from the skycrane on a 21-foot bridle so that the rocket's exhaust doesn't kick up too much dust into the rover's instruments when it reaches the surface, and cutting the bridle on touchdown and then diverting the skycrane very far from the rover to land (crash) elsewhere. These are only some of the challenges—see the "7 Minutes of Terror" video to view the rest.
Possible landing sites for Curiosity had to be below an elevation of 0 kilometers and had to be within 30 degrees latitude of the equator to stay warm enough all martian year round (and therefore save the power supply for locomotion and the science experiments without using power to warm the electronics during the cold nights and winters). Gale Crater won out over three other candidates. Gale Crater is 96 miles across with a large mountain that appears to be the remnant of an extensive series of deposits. The layers at the base of the mountain contain clay and sulfates that very likely formed in liquid water. Curiosity will determine if that site could have supported life and if the conditions are right for preserving clues of any possible past life. It will have the instruments needed to find any organic molecules (meaning carbon-based molecules) in the rocks and soil. While Curiosity won't have the instruments to detect biological activity nor image microorganisms, it will be able to do an isotopic analysis of the carbon and other elements in the rocks to look for ratios of the isotopes that would be indicative of life or past life. Curiosity will also investigate: the geology of the area to figure out the rocks and soil formed; how the atmosphere has changed through time and the cycling of water and carbon dioxide; and the radiation environment at the surface (photons and particles from the Sun and the rest of the galaxy).
The sequence of images below show you where Gale Crater is located at 4.5 degrees south latitude, 137.4 degrees east longitude. It is on the boundary between Mars' cratered southern highlands and its smooth, northern plains. The green box shows the area of the next image. The final image shows where Curiosity actually landed—look for a small green box slightly to the right of the center (select the image to bring up a full-size version to see that small green box more easily).
Landing ellipse on northern side of large central mountain indicated. The small green box to the right of the center of the ellipse is where Curiosity actually landed. Select the image to bring up the full-size version of the image. Curiosity landed about 2 kilometers northeast of the target center.