Are moon rovers designed with two headlights like an Earth car, or, just a single headlight in the middle?

Does it make sense to have two headlights when there are no lanes, side walk or traffic coming your way in an opposite parallel direction (that's why the lights on real cars are asymmetric)?

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    $\begingroup$ I don't think rovers even have headlights as they only operate in daytime because they're solar powered. I may be wrong though. $\endgroup$ – Star Man Oct 13 '19 at 21:36
  • $\begingroup$ @StarMan: during the day? It's always night time in the moon. $\endgroup$ – Quora Feans Oct 13 '19 at 22:20
  • $\begingroup$ Who told you that? Of course there is daytime on the Moon. Daytime is defined as the "side of a celestial body facing the Sun". There's around 14 earth days of daytime on the Moon and 14 earth days of nighttime on the Moon. $\endgroup$ – Star Man Oct 13 '19 at 22:22
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    $\begingroup$ The far side of the moon has daytime too. When it's daytime for the side facing us, it's nighttime for the far side and when it's night time for the close side, it's daytime in the far side. $\endgroup$ – Star Man Oct 13 '19 at 22:26
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    $\begingroup$ I think this is a really interesting question! There is some background information in answers to Has any lander or rover (besides Huygens) used a flood-light for photography? and also If Curiosity had lights, could it drive or work in the evening? $\endgroup$ – uhoh Oct 14 '19 at 3:22

It makes sense to have more than one headlight. If you have a single headlight, you create hard shadows behind obstacles. With two or more lights placed in different locations on the rover, the amount of shadow reduces. It also adds redundancy.

These days, people here on Earth who drive in unlit terrain have switched to light bars, which take this idea a step further:

enter image description here

All Moon rovers so far have not been operated in the dark. Even in daytime, astronauts using the LRV reported difficulty reading the terrain (estimating distances and scales); this would be harder in the dark. Robotic rovers don't have to rely on visible light cameras alone. Estimating distances becomes much easier if you have radar or lidar sensors, for instance.

  • $\begingroup$ "If you have a single headlight, you create hard shadows behind obstacles." Isn't this exactly what happens now? The Sun's 1D half-power width is a lot less than 0.5 degrees, and shadows shown in moon photos certainly look "hard". So considering this is exactly the conditions under which all lunar rovers to date have operated, I have a strong hunch that these shadows have been exploited, thus I've just asked Have lunar (or Martian) rovers exploited shadows, perhaps for terrain comprehension or obstacle avoidance? $\endgroup$ – uhoh Oct 14 '19 at 7:17

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