The world of eternal traces

On the shores of the unknown, we found strange traces.
- Arthur Eddington

From the very dawn of humanity, we left innumerable traces on different lands, traveling to all corners of the planet.



But, with rare exceptions , these traces are not preserved. There are enough winds and rains all over the Earth, as well as other natural phenomena. Usually after a little time, all the memory of the traces is erased from the changing landscape.


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But what about worlds without winds and rains? What about a world without atmosphere?



Without rains, winds, snows, glaciers, landslides and other ways to move and mix, for example, dust on the surface of the moon, the trace you left can
stay there forever.



As far as we know, the only way to mix particles of moon sand on its surface will be a blow to it from meteors, asteroids and comets.



They create impact craters, raise lunar dust, which as a result settles to the surface. Over time, either a sufficiently large blow, or a sufficiently large number of small collisions with the Moon of fragments from the solar system will erase our traces from it.

But so far this has not happened. How do we know this?



This Lunar Reconnaissance Orbiter (LRO), revolving around the moon for several years, and taking pictures of its surface of the highest resolution. In the course of the mission, he transferred 192 TB of data to Earth.

Naturally, the thought immediately arises: if we have a very high resolution camera flying around the moon, wouldn't it be interesting to photograph the landing sites of the Apollo missions?



And although LRO was already carrying out such tasks, he now used the full power of his tools — especially the new low-orbit Narrow Angle Camera — to photograph three landing sites — the Apollo missions 12, 14, and 17.

Let's take a look at the detailed images of the first tracks on the surface of the moon!



How were they made ? The LRO orbit was changed so that it was very low when flying over the landing sites, so low that the resolution of the photo above was only 35 cm per pixel! This amazing image of Apollo-12 shows not only the landing site (in the picture - “Intrepid Descent Stage”), but also the Surveyor 3 probe, which has been there since 1967 - astronauts from Apollo-12 visited it two and a half years later.

You can see the bright L-shaped shape next to the ALSEP equipment tag (Apollo Lunar Surface Experiments Package - a set of scientific tools for studying the lunar surface). L is visible due to the reflective surface of the power cables coming from the central station to the two instruments. And although the diameter of the cables is smaller than the pixel size, their reflectivity makes them visible.

Finally, you can see dark dents running around and between the edges of the craters. But these are not channels - they are traces of astronauts! Without strikes from meteorites over the past 42 years, traces are visible just as they were visible at the time of creation. From 2016 we are looking at 47 years in the past and we see that they have not changed.



Apollo 14 is not so colorful, but perhaps more famous. You can see the descent module, equipment ALSEP, but basically everything. Except, again, traces. And whose are they? Edgar Mitchell and Alan Shepard. At the end of the second moon walk, Shepard hit the golf balls, sending them "many miles," he said.

I left the most interesting thing in the end.



Apollo 17, where Eugene Kernan and Harrison Schmitt were the last people to walk on the moon, looks different in high definition. The descent module, ALSEP and traces are still visible on the surface.

But if you look closely, you can see something marked “LRV” and a lighter set of two parallel tracks. Do you know what it is?



This is the lunar rover Apollo . It was used in missions 15, 16, and 17, its footprints on the surface are different from those of people, and with it, astronauts moved much further than they did last time. Traces of the 17th mission do not even fit in the photo - they stretched for 36 km, and he was 7.6 km away from the landing site. And his tracks also remained in perfect condition after more than 40 years.

It is surprising that after so many years the traces of humanity on the moon remain almost unchanged. They can stay there for millions of years, or a collision with a small asteroid can instantly destroy them.

More high-resolution photos can be seen at the link . NASA also released a selection of videos and interviews about these photos.