Chang'e 3 update with lots of pictures: Yutu begins lunar journey
Posted by Emily Lakdawalla
23-12-2013 14:54 CST
There was a lot of action on Chang'e 3 over the weekend! The first thing I want to share with you is this cool little video of the rover rolling, evidently shot on the Moon. I took it from this news report on Youtube. It was a television camera recording of a video monitor, so the color is all washed out, but you are looking at video of a rover making tracks on the dusty surface of another world. Tremendous.
A little story -- I didn't know the date of the image but could figure it out with some help from Phil Stooke's route map, below. We have a side view of the rover in motion, so it was taken before the December 22 drive when the rover drove due south. We know it was after lunar noon, so it can't have been taken when the rover was on the due-south leg of its circumnavigation of the lander. It had to be facing southwest. Thus, the video was taken on December 21.
So what is the current plan for the mission? An update about the state of the mission was posted in English at cntv.com yesterday. They quote lunar exploration program chief designer Wu Weiren as saying:
Ten pictures have been taken at five spots so far, and all of them are better than we expected. The rover has moved in a semi-circle around the lander. Afterwards, they will begin to conduct scientific explorations of the geography and geomorphology of the landing spot and nearby areas, and materials like minerals and elements there. We will also explore areas 30 meters and 100 meters beneath the lunar soil [This refers to the ground-penetrating radar instrument --ESL]. The exploration will continue longer than we planned, because all the instruments and equipments are working very well.
That's good news! This story from chinanews.com adds to that, stating that the rover's arm has safely been deployed for the first time. The mission is hurrying to complete checkouts of the rover systems before night begins to fall and the rover has to hibernate for two weeks, beginning December 26.
You can see from the map that the rover has left the lander behind, embarking on her lunar journey, toward the south. Here is a lovely picture of that. This is the first picture I have seen from the Chang'e 3 mission that appears to be a direct-to-the-Web digital image -- it has not been through multiple video compressions first. Absolutely lovely.
I tweeted this image over the weekend, and among the responses I received was one from Curiosity engineer Bobak Ferdowsi, who remarked on how strange it was to see a brightly lit rover on the surface with black black black space above it. So different from Mars!
Several commenters asked why no stars are visible in the sky. If you can see space, why no stars? It's a matter of contrast -- there is so much light being reflected off of the lunar surface that the exposure of the photo is too short to reveal the far fainter stars in the sky. However, if you pointed a camera at space and prevented stray Moon-light from entering your camera's field of view, you'd be able to take longer exposures and you'd see plenty of stars. In fact, that's one of the experiments on the Chang'e 3 lander -- astronomy performed by a camera sitting on the airless surface of the Moon.
Here's another picture of the rover at the same position (you can tell from features on the ground), except the rover has rotated and the mast is tilted down -- maybe for imaging of the surface?
And now, some views of the lander. Here's the best one I've seen, taken after the rover drove around to the lander's south, so now it's nicely lit. There are a few more views of the lander from different perspectives (grabbed from television broadcasts, so they are lower quality), shared in this post on nasaspaceflight.com.
Ricardo Nunes pointed out at unmannedspaceflight.com that two of the photos were taken from slightly different perspectives. That means I can give you a 3D photo of the lander on the Moon! Get your red-blue glasses, or select one of the other 3D display options below!
These photos were part of a post-landing campaign of mutual imaging of rover and lander. Here's a graphic describing the campaign.
Editorial note: Christmas is in two days, and I'm going to try to take some time off in the next week, so this may be my last post for several days, unless something happens that I can't not write about. Happy solstice and merry Christmas!