But won't Earth look how Mars looks to us?. An above average star in the night sky.

The MRO has already imaged the Earth and Moon from a Martian orbit.

Curiosity is designed to study the Martian surface, not take pictures of the Earth, so it isn't going to beat that!

I never thought in a million years they would land this in one piece , Well done NASA !

Must say, I didn't really grasp just how big and heavy Curiosity really is.

Impressive as that is, I bet the sky-crane part of it was a properly serious bit of kit.
Hard to believe that the crane and rover were held aloft by 4 rocket motors which only used 260kg of fuel.

Anybody know how long the rockets fired for while dropping the rover?

Do you think it will ever be possible for video to be sent from one of these landers?

I don't see why not eventually. Obviously it would start at a very low resolution and frame rate.

Don't see why.

The cameras on Curiosity are HD.
Probably not going to be possible to send HD video in real-time but there's no reason why it couldn't record as it moves around, for surveying purposes for example, and then send the footage back so the boffins can review it and pick out points of interest for further exploration.

The mastcam cameras on Curiosity can do 720p at 10 frames per second. In 3D if they choose to combine the imagery.

Wouldn't the problem be the bandwidth, bearing in mind that over that distance there would need to be a great deal of redundancy for error correction?

Yes, obviously it could be recorded. I was thinking that the questioner meant real-time.

There's another point, would moving pictures actually be worthwhile? For example, could you see particles moving during a dust storm?

watched this live this morning, amazing stuff, a truly amazing feat of engineering.
Well done to everyone at NASA, cant wait for the first results to come out.

Had to go straight to sleep after the first images came out, as i was up all night.

Need a few more hours really.

That was a success, i just hope the Martians don't take it out

Maybe there was room to fit Tom Cruise inside the rover, so he can fight them up there

The Martians won't attack yet, they're all watching the Olympics.

Can't remember where I saw it but there's a pic' where they used Curiosity's camera to photograph a $1 bill from 10ft away and you can clearly see the patterns in the inking on the bill.

Again, I have no idea whether Curiosity has the bandwidth to send such HD images back in real-time but I'm sure they'll be able to video all sorts of stuff in HD and then send it back afterwards.

Thing is, given the time-lag to send signals to Mars, I doubt much will be happening in real-time anyway.
It's not like they'll have a guy with a joystick and a screen controlling it.
It'll be more like programming a Big-Trak, where you tell it "Go 20ft forwards, record some video, take a soil sample, take an air sample and then report in when complete" then hit the "send" button and wait until it completes whatever you've told it to do.

It's not really about bandwidth though; it's about the time taken for the signal to travel from Mars to Earth, and then from Earth to Mars.

Given that it's 15 minutes of light travel time each way, I would imagine real-time coms to be impossible.

Yes, obviously it'll be delayed by the time it takes for the signal to travel from Mars to Earth. There is no solution to that unless Einstein was fundamentally wrong. By real-tme I meant transmitted from Mars as a camera captures it. This is no different to real-time from the Moon, or on Earth - just a much longer time for the signal to arrive.

Errr....I hate to be a pedant, but there IS a difference in time on Mars and Earth, due to Mars having less gravity. One second on Mars is not the same time as one second on Earth

But in this instance, I guess there might not be enough badwidth to send video in "real-time" as Si has pointed out.

That was kinda my point.

Cos it won't be possible to do anything in real-time anyway there won't be any constraints on video quality due to the need to get the data back in "real-time".

The only constraints will be the limit of whatever storage medium Curiosity has.
They'll be able to tell it to shamble about for a few hours, taking pictures and videoing stuff as it goes and then just beam it all back to Earth when it's done so the chances are that the images and video we get to see will be pretty good quality.

Sorry if I didn't make that clear at first.

I don't think the gravity has got anything to do with it, AFAIK it's purely the time taken for each planet to rotate on its axis by 360 degrees relative to the sun.

It also depends how you define a second. For example, that can be the current scientific definition (the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom; i.e. the same everywhere in the universe), or as 1/(60*60*24) of a average Earth day (again, the same everywhere), or as 1/(60*60*24) of an average day on the particular celestial object in question (i.e. different on Mars to Earth).

Nothing is truly real-time. It takes time for light from whatever you are looking at to reach your eyes, time for your retina cells to react, and time for the nerve signal to travel from your retina cells to your brain. It's only a question of how long that time is, which is (mostly) a function of the distance.

Agreed 100%

Well, you can define that as your second everywhere in the Universe, and that's fine, but the seconds still won't be the same length if you measure them in different gravitational fields, or at different relative velocities...

But that's a rather silly digression from the main point.

IIRC, the Curiosity cameras have a rather modest 8 Gb storage capacity, so that limits how much data can be buffered up, and I don't know what the available bandwidth is once the high gain antenna is deployed, although it should be easy enough to find out.

Replaying it on Eyes on the Solar System they fired for 57 seconds from an altitude of 5,510.3 feet, when Curiosity was descending at a speed of 176 mph.

Were you using that at the time of the descent and landing?

I couldn't understand why the view I was getting was from underneath the lander, while the one that was showing on one of the big screens in the control centre was from the top. I couldn't find an option to change it to match what their screen was showing.

Some years ago when the Mars Polar Lander arrived at Mars I used some sort of Mars globe programme to keep track of night/day on Mars. Now try as I might I cannot findthat site or indeed anything similar.

Does anyone know of a site like that?

We're going way off-topic here about a wee bit pedantry. Regardless of how you measure a unit of time, that unit will appear to take more or less time from the observers point of view.

It's all about relative motion and time dilation. When you consider that an atomic clock on a typical GPS satellite would tick faster by 38 microseconds due to Special (motion based) Relativity and General (warping of space time) Realativity.

So, because Mars has less density, it has less gravity (that is, it wraps space-time around it less than Earth does) so time advances at a different rate because of General Relativity as well as Special Relativity ( the motion based part that you pointed out).