<div dir="ltr">In this blog report of a seminar on the (apparently increasing) likelihood of water ice in deep, permanently shadowed craters on Mercury's poles, the author repeatedly uses the phrases "permanent shadow" and "permanently shadowed".<br>
<div><br> <a href="http://www.planetary.org/blogs/guest-blogs/2013/lpsc2013-mercury-shadowed-craters.html">http://www.planetary.org/blogs/guest-blogs/2013/lpsc2013-mercury-shadowed-craters.html</a><br><br></div><div>These three articles about similar phenomena on Luna use the same phrases.<br>
</div><div><br> <a href="http://www.esa.int/Our_Activities/Space_Science/SMART-1/Shackleton_crater_SMART-1_s_search_for_light_shadow_and_ice_at_lunar_South_Pole">http://www.esa.int/Our_Activities/Space_Science/SMART-1/Shackleton_crater_SMART-1_s_search_for_light_shadow_and_ice_at_lunar_South_Pole</a><br>
<br> <a href="http://onlinelibrary.wiley.com/doi/10.1029/2002GL016180/full">http://onlinelibrary.wiley.com/doi/10.1029/2002GL016180/full</a><br><br> <a href="http://www.lpi.usra.edu/meetings/lpsc2013/pdf/2590.pdf">http://www.lpi.usra.edu/meetings/lpsc2013/pdf/2590.pdf</a><br>
<br></div><div>If there's an astronomy word for this, it seems likely that it's as obscure as OUR words. So I propose we invent the word.<br><br>"Umbra" is the astronomy word for shadow. Specifically, it means the center portion of the eclipse shadow. The word is Latin for "shade" or "shadow"<br>
<br>"Perpetual" or "Permanent" both come from Latin, thus would be good matches for "Umbra". So ...<br><br></div><div> "perpetumbra" <br></div><div> "permanumbra"<br>
<br></div><div>... seem the best choices. I'm inclined toward the latter: as being similar to "permafrost" and "penumbra". Now we just need to find an excuse to get it into publication and then call the publication to the attention of the scientists in the articles cited above. *G*<br>
<br></div><div> "Mercury's Permanumbra<br></div><div> "Search for Permanumbral Ice at Lunar South Pole"<br> "Permanumbra in Simple Craters Near the Lunar Poles"<br> "Characterization of Lunar Polar and Non-Polar Permanumbra Physical and Thermal Characteristics"<br>
</div><div><div class="gmail_extra"><br>BB,<div>Hutch</div><div> </div><div>-----BEGIN GEEK CODE BLOCK-----</div><div>Version: 3.1</div><div>GCM/S d+>- s+:+ a++ C+++$ ULAC>$ P+ L+ !E W++$</div><div>N+ o K? w++++/--$ O? M- V? PS+ PE/- Y PGP- t++ 5?</div>
<div>X-- R !tv? b++++>$ DI++++ D G+> e++ h+ r--?* y++></div><div>------END GEEK CODE BLOCK------</div><br><div class="gmail_quote">On Tue, Dec 24, 2013 at 8:36 PM, eLLioTT morEton <span dir="ltr"><<a href="mailto:em@swarpa.net" target="_blank">em@swarpa.net</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="im">On Mon, 23 Dec 2013, Jim Moskowitz wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Elliott: "Someone must have a name for this (ecologists? orienteers? real-estate agents?).<br>
</blockquote>
<br></div>
*Does* anyone know what it's called? Is there an astronomy word for a body that is permanently in the shadow of another?<br>
<br>
Regards,<br>
em<br>
</blockquote></div><br></div></div></div>