The travels of China’s Yutu-2 rover on the Moon


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Yutu-2 and Chang'e-4
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The Lunar Reconnaissance Orbiter (LRO) science team today released images that track the travels of China’s lunar rover Yutu-2 from its landing on January 30, 2019 through June 3, covering the rover’s first six lunar days on the Moon.

The image to the right, cropped, reduced, and annotated to post here, shows the relative positions of both spacecraft as of June 3, 2019. In the release they also included a gif movie showing the progression of Yutu-2’s movements since landing.

Once a month, LRO passes over the Chang’e 4 landing site, allowing LROC to capture a new image. LROC has now imaged the site five times (since the landing) and observed Yutu-2 to have traveled a total of 186 meters (distance measured using the rover tracks). If you squint, portions of the rover tracks are visible as a dark path in the images from April, May, and possibly June.

table of Yutu-2's movements through June 2019

The LRO release also included a table showing the distance Yutu-2 has traveled with each lunar day, shown on the right. The table does not include the 23 meters (75 feet) the rover traveled on its sixth lunar day. My estimate yesterday that Yutu-2 was traveling an average of about a 100 feet per day, with the distances per day shrinking with time, seems largely correct. During the rover’s fourth and fifth lunar days it moved very little, either because they had found something very interesting they wanted to inspect more closely, or they were moving more cautiously as the rover’s life extended past its planned lifespan of three lunar days.

On the sixth day however they increased their travels again, suggesting that either they had finished the observations at the previous location, or they had gained more confidence in the rover’s staying power.

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