note: Answer(s) to Why is a corner of InSight's selfie cropped like this? don't address this question about Curiosity for several reasons:

  1. It doesn't even answer that question properly.
  2. Insight is not a rover and does not have anywhere near the same number of additional cameras as does Curiosity.
  3. Insight does not produce nearly as many photos per camera as does Curiosity, because (did I mention) Insight is not a rover, and so there is less public activity analyzing, composing montaging and otherwise working with it's images as there is for Curiosity's large body of photographic work.
  4. I can't prove it but I'll bet there has been fewer full selfies initiated by Insight than by Curiosity.

The new NASA video How NASA's Mars Curiosity Rover Takes a Selfie answers the question I always wanted to ask; How (the heck) does Curiosity take its selfie?

The video shows the rover's robotic arm move MAHLI (the Mars Hand Lens Imager) through a wide range of positions and directions.

Presumably the video shows this because there's another camera on the rover imaging the robotic arm.

And yet the robotic arm is missing from the final image.

Question: Why is this part of the rover therefore still missing from most selfies? Has this been discussed in authoritative sources? Have attempts been made to include it, at least in black-and-white?

GIF from screen shots from the linked video demonstrates the wide range of motion and orientation of the robotic arm as seen from another camera on Curiosity.

Curiosity's MAHLI GIF from How NASA's Mars Curiosity Rover Takes a Selfie

From Seventeen Cameras on Curiosity**:

NASA: Seventeen Cameras on Curiosity

  • $\begingroup$ Does this answer your question? Why is a corner of InSight's selfie cropped like this? $\endgroup$
    – user20636
    Mar 21, 2020 at 9:07
  • 1
    $\begingroup$ for the same reason you don't see your hand when you take a selfie $\endgroup$
    – user20636
    Mar 21, 2020 at 9:16
  • $\begingroup$ @JCRM quipy but wrong. Read the question in toto and give it some more thought. I you'd like to post a proper answer where voting is possible that would be great! $\endgroup$
    – uhoh
    Mar 21, 2020 at 9:57
  • $\begingroup$ @JCRM while related, your proposed dupe does not really answer the question as I have written it. I invite you to have another look at it and then reconsider, thanks! $\endgroup$
    – uhoh
    Mar 21, 2020 at 9:58
  • 1
    $\begingroup$ @uhoh - have you read this: planetary.org/blogs/emily-lakdawalla/2015/… $\endgroup$
    – amI
    Mar 22, 2020 at 5:27

1 Answer 1


It's two reasons actually. Since the MAHLI has a narrow FOV, it can't fit the entire rover in one photograph. Similar to the reason why you don't see your arm when you take a selfie. The camera's FOV isn't big enough to fit your arm (unless you point the camera down, then your arm will be visible). However, this is only the case when the MAHLI images the upper part of the rover. The arm should be visible when photographing the wheels, the bottom of the rover, and etc, right? The second reason is that NASA crops the arm out of the individual photos and merges it with another photo. Here's a visual example of this: enter image description here

This was image was originally from this Quora answer. Here is NASA's explanation from this source:

MAHLI is mounted on a turret at the end of Curiosity's robotic arm. The arm is not visible in the portrait because the arm was positioned out of the shot in the images or portions of images used in the mosaic. Some images taken during the day show portions of the arm. However, the Martian ground that the arm hides from view in those images is visible in alternative images chosen for the mosaic, taking the arm out of the scene.

  • $\begingroup$ I show and refer to images of MAHLI and its arm from a wide range of perspectives and mention attempts in black-and-white is to drive the point home that Curiosity has a large number of cameras. This answer only addresses images by MAHLI. So your "two reasons" about the MAHLI camera don't really address my question. If I had asked "Why aren't there any photos of the photographer?" The answer is not "Because they didn't bring a selfie stick" because all of the other people in the photos had phones with cameras. They could have photographed the photographer. $\endgroup$
    – uhoh
    Mar 22, 2020 at 23:51
  • $\begingroup$ @uhoh - The MastCams and HazCams are not suitable for a self-photo -- they are more like a helmet mounted GoPro. MAHLI is the only handheld camera available, so it's the only way to take a selfie (without a mirror or a detachable camera or another lander nearby). $\endgroup$
    – amI
    Mar 23, 2020 at 7:05
  • $\begingroup$ @amI I have a reasonable understanding of how cameras work. Why suppose that one must choose only one camera for a profoundly composite image? My question asks about attempts in black and white so starting with a MAHLI set and then adding to them more images just for example like those I show in the question could work. You'd have do more of the same creative cropping to make the background work is all. $\endgroup$
    – uhoh
    Mar 23, 2020 at 7:09
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    $\begingroup$ @uhoh - what good is a picture of your arm taken from your shoulder if you want your arm to appear in a composite selfie? $\endgroup$
    – amI
    Mar 23, 2020 at 7:20
  • 1
    $\begingroup$ @uhoh - perhaps you could sketch the scene that you desire -- then imagine what camera takes a picture of the arm so that it's in the same scene as the chassis (without looking like a Picasso painting). $\endgroup$
    – amI
    Mar 23, 2020 at 7:40

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