<p>I have the impression these were first observed in images taken by the <a href="https://en.wikipedia.org/wiki/Mars_Orbiter_Camera" rel="nofollow noreferrer">Mars Orbiter Camera (MOC)</a> of the Mars Global Surveyor, probably sometime between 1997 (arrival at Mars) and 1999 (when the main mapping program began) -- or possibly as late as 2000 (when they are first mentioned).</p>
<p>In <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2002JE002007" rel="nofollow noreferrer">Piqueux et al. (2003)</a>, a paper specifically focused on the spiders, they say</p>
<blockquote>
<p>The term ‘‘spiders’’ was used by Kieffer [2000] (although the term may
have originally been coined by Andy Ingersoll [H. Kieffer, personal
communication, 2003]) and we use this term in this paper.</p>
</blockquote>
<p>In <a href="https://www.lpi.usra.edu/meetings/polar2000/pdf/4095.pdf" rel="nofollow noreferrer">Kieffer (2000)</a> we find this statement</p>
<blockquote>
<p>Dark radially converging dendritic patterns are visible in MOC images
of some portions of the spring polar cap [7]; these have been termed
&quot;black spiders&quot; by the MOC team [8].</p>
</blockquote>
<p>Unfortunately, the published version of that short conference proceeding article is missing all of the references after number [4], so I don't know if there is more specific useful information available. The conference at which Kieffer (2000) was presented was in August, 2000, so I'd put mid-2000 as the latest possible date.</p>

CC BY-SA 4.0
2021-05-09T17:32:48.917Z
2021-05-09T17:32:48.917Z
Peter Erwin
<p>On Mars, there are spider-looking features near the South pole that <a href="https://www.uahirise.org/epo/nuggets/martian-spiders-lab.pdf" rel="nofollow noreferrer">might be caused by CO2 sublimation</a>. When were these features first observed on the surface of Mars?</p>

<mars><surface>
When were the spiders first observed on Mars?
usernumber
# When were the spiders first observed on Mars?

(Asked by: username_0 on 2021-05-09)

On Mars, there are spider-looking features near the South pole that [might be caused by CO2 sublimation](https://www.uahirise.org/epo/nuggets/martian-spiders-lab.pdf). When were these features first observed on the surface of Mars?

**Tags:** mars, surface


---

## 1 answers

### Answer by username_1 on 2021-05-09. Score: 2 | Accepted answer

I have the impression these were first observed in images taken by the [Mars Orbiter Camera (MOC)](https://en.wikipedia.org/wiki/Mars_Orbiter_Camera) of the Mars Global Surveyor, probably sometime between 1997 (arrival at Mars) and 1999 (when the main mapping program began) -- or possibly as late as 2000 (when they are first mentioned).

In [Piqueux et al. (2003)](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2002JE002007), a paper specifically focused on the spiders, they say

> The term ‘‘spiders’’ was used by Kieffer [2000] (although the term may
> have originally been coined by Andy Ingersoll [H. Kieffer, personal
> communication, 2003]) and we use this term in this paper.

In [Kieffer (2000)](https://www.lpi.usra.edu/meetings/polar2000/pdf/4095.pdf) we find this statement

> Dark radially converging dendritic patterns are visible in MOC images
> of some portions of the spring polar cap [7]; these have been termed
> "black spiders" by the MOC team [8].

Unfortunately, the published version of that short conference proceeding article is missing all of the references after number [4], so I don't know if there is more specific useful information available. The conference at which Kieffer (2000) was presented was in August, 2000, so I'd put mid-2000 as the latest possible date.


---

