We are on Mars
Posted by Emily Lakdawalla
2012/08/06 05:19 CDT
Oh my goodness. Where do I begin?
I guess this is the best place to start: we have six shiny new wheels sitting on Martian soil, and a rover throwing its shadow onto the surface. Fuzzy and dust-spattered as they are, I agree with Project Scientist John Grotzinger that these are among the most beautiful pictures of Mars that I have ever seen.
I needn't retell the details of how the landing happened, because it was completely according to plan. I don't think a single thing happened that was unexpected.
The landing was successful, and in the end, after all that anticipation, it was over so fast. Trying to gather my thoughts, the one that dominates is "I really can't believe that worked." But it did. It actually did. Up there, on Mars, there's a new rover, bringing us back up to two. Nothing could replace Spirit, but Curiosity will carry her torch.
This is the dawn of a new era in the exploration of Mars. Just as every previous mission has, the data that Curiosity sends back will completely change our view of the planet.
I live-tweeted the whole thing. I could keep up with the narration through the entry phase, but once the parachute opened things happened very quickly. With every milestone successfully passed, you could hear the anticipation and excitement in Allan Chen's voice ticking up a notch. He was practically screaming the last milestones. We certainly were yelling in the press room. Once it was all over, and there was jubilation in the mission control area, I actually started hyperventilating. I would've passed out if I'd been standing up. (Fortunately, I have a very comfy chair.)
There's not a lot of information yet available on details of the landing -- accuracy, position, and whatnot -- but those details really don't seem all that important to me right now. It's the road ahead of us that's important. From what I can see in the images downlinked so far, that road will be a smooth one, at least at the start. The pebbles on the ground in front of us look pretty small. Of course it's important to remember that the wheel that we see in those images is twice the size of the wheels on Opportunity. All of those pebbles would look a lot bigger to our little friend down in Meridiani.
Before I go on about those images, I think we should all stop and spare a thought for the machinery that didn't land so softly. The cruise stage; the heat shield; the aeroshell and parachute; the descent stage. Thousands of people labored for years to design, build, program, and test those machines, and they are now wreckage scattered across Gale crater. Curiosity will almost certainly not visit any of them, but we'll get a very good look at them soon when Mars Reconnaissance Orbiter images the landing site, possibly in the next day or two. If the sharp-eyed HiRISE doesn't catch them in its skinny field of view, the Context Camera surely will.
So: What can we learn from the first photos? First of all, I should probably explain that these images were taken with fish-eye cameras on the belly of the rover whose purpose is to assess the terrain in the immediate vicinity of the rover's wheels. The horizon is warped due to the fish-eye view; it's actually quite flat.
Note the direction of the rover's shadow. The rover is near the equator, and it was midafternoon when it landed. Therefore, the rover is facing almost directly east.
Next, what an incredibly smooth surface! Look at all those little pebbles! Once they're ready to drive -- which I should remind everyone will not be for a few weeks, not more than baby steps anyway -- it should be pretty clear sailing.
Here's the only image released from the second Odyssey communications pass. It was a low-elevation pass, so not much data was transmitted. This one is from the rear hazcam and was taken after deploy of the lens covers. The rover is facing due east. In the hour-plus since landing, the Sun sank considerably to the west, and is now in the rear hazcam field of view. Its glare is washing out almost all of the detail.
This one provides a good test for how much information is being lost in the compression that they do before they post raw images online. Let's see if we can get any detail at all out of it by adjusting the contrast. There you go -- the rim of Gale crater. The blockiness results from it being JPEG-compressed. Still, I'm pleased that I can get any detail at all out of this.
Here's a different stretch of the same image, one released by NASA. This one looks better because, of course, they had access to the real data. It brings out much detail in the pebbled plain and on the left rear wheel of the rover (right side of this image, which is facing rearward). I'm trying to figure out the maximum size of the pebbles, but it's hard. This camera is identical in most ways to the hazcams on Opportunity, but its position is higher and significantly to the right of center (which is why we only see one wheel); and the wheel in the foreground is twice the size of Spirit and Opportunity's. In my tired state I can't figure out their size.
But here's the coolest (and, admittedly, most speculative) thing I can see in the images. In both of the rear hazcam images taken just after landing, there is a strange shape on the horizon. It is not there in the later view. It is there in both left and right eye views. It is something that was there just after landing, and is not anymore. My hypothesis is that we may be seeing the cloud marking the crash site of the descent stage. Others on unmannedspaceflight.com have proposed the same. It seems crazy that we should see that, but I can't think of any other explanation for a puff-shaped thing on the horizon seen right after landing and not later. Which makes me laugh, because I've always given Doug Ellison a hard time for not including that detail in his otherwise excellent animation showing the landing. (Which he responds to by asking me if I'm crazy to think that NASA will show themselves blowing things up on Mars.) Looking forward to asking the mission people what they think about this.
Via Twitter I've learned that HiRISE succeeded in getting its image of Curiosity under parachute, and the image allegedly looks spectactular; but we won't see it until the 9:00 PDT / 16:00 UTC press briefing. I can't wait! It's 3 a.m. here. It hardly seems worthwhile to go home at this point; my kids will be up in three hours anyway. Might as well stay here. The next Odyssey communications pass is around 11:00 (18:00 UTC). Not sure if I'll be able to make it until that.