Difference between revisions of "May 1, 2004"

From LPOD
Jump to: navigation, search
Line 31: Line 31:
 
<p align="center" class="main_titles"><b>Author & Editor:</b><br>
 
<p align="center" class="main_titles"><b>Author & Editor:</b><br>
 
[mailto:tychocrater@yahoo.com Charles A. Wood]</p>
 
[mailto:tychocrater@yahoo.com Charles A. Wood]</p>
<p align="center" class="main_titles"><b>Technical Consultant:</b><br>
+
<!-- Cleanup of credits -->
[mailto:anthony@perseus.gr Anthony Ayiomamitis]</p>
+
<!-- Cleanup of credits -->
<p align="center" class="main_titles"><b>A service of:</b><br>
+
<!-- Cleanup of credits -->
[http://www.observingthesky.org/ ObservingTheSky.Org]</p>
+
<!-- Cleanup of credits -->
<p align="center" class="main_titles"><b>Visit these other PODs:</b> <br>
+
<!-- Cleanup of credits -->
[http://antwrp.gsfc.nasa.gov/apod/astropix.html Astronomy] | [http://www.msss.com/ Mars] | [http://epod.usra.edu/ Earth]</p>
+
<!-- Cleanup of credits -->
 +
<!-- Cleanup of credits -->
 
<p>&nbsp;</p>
 
<p>&nbsp;</p>
 
----
 
----
 
===COMMENTS?===  
 
===COMMENTS?===  
 
Register, and click on the <b>Discussion</b> tab at the top of the page.
 
Register, and click on the <b>Discussion</b> tab at the top of the page.
 +
<hr>
 +
<!--
 +
You can support LPOD when you buy any book from Amazon thru [[Support_ LPOD|LPOD]]!
 +
-->
 +
<span style="font-size:88%">
 +
<center>
 +
Contributions to http://www2.lpod.org/ are licensed under a Creative Commons Attribution No-Derivative-Works Non-Commercial 3.0 License. [http://www.creativecommons.org/licenses/by-nc-nd/3.0 http://www.wikispaces.com/i/creativecommons/by-nc-nd_3.0_80x15.png]<br>
 +
</center>
 +
</span>

Revision as of 12:13, 1 February 2015

Serenitatis Diameter Sequence

LPOD-2004-05-01.jpeg

Serenitatis Diameter Sequence

Have you heard of the North Polar Sequence? It is a series of 96 stars near Polaris whose brightnesses and colors were accurately determined as standards for stellar astronomers. There has not been a comparable standard sequence that would permit lunar observers to judge their observing conditions, telescopic performance, visual acuity or imaging limits. The above image of Mare Serenitatis (and the mouseover larger version) is the first attempt to provide such a standard sequence of crater diameters for lunar astronomers. Serenitatis is a good place for a lunar diameter sequence because it is a relatively uncomplicated surface with a small number of pristine craters that can be confidently identified with a little care. An important characteristic of a standard sequence is its accuracy. I have measured all of these crater diameters, some during the early 1970s when I led a project to catalog lunar craters using Lunar Orbiter IV images. I made other measures in the last few days, using the 1:1,000,000 Mare Serenitatis Lunar Map published by NASA in 1976, and online Lunar Orbiter images. Most of the diameters are probably correct within 100-200 m. This Consolidated Lunar Atlas image, obtained with a 61" reflector, seems to have a resolution of about 2 km - craters larger have clearly defined rims, and smaller ones show up only as small white spots. Today, amateur imagers with telescopes 1/10th this aperture can equal and exceed this wonderful CLA image.

Chuck Wood

Technical Details:
I have used the classic nomenclature, rather than the needless new names that replace lettered designations. The equivalences are: Bessel E = Bobillier; Linne E = Banting; Bessel A = Sarabhai; Le Monnier B = Very; Le Monnier C = Borel. Remember, the letter is placed on the side of its crater closest to it patronymic crater - e.g. the A for Bessel A is on a line between Bessel A and Bessel. Note that I have given diameters for a few craters west of Posidonius that lack designations - to reduce future ambiguity I number them 1 thru 3.

Related Links:
Lunar Orbiter IV View 1
Lunar Orbiter IV View 2

Tomorrow's LPOD: Lunar Eclipse Preview


Author & Editor:
Charles A. Wood

 


COMMENTS?

Register, and click on the Discussion tab at the top of the page.


Contributions to http://www2.lpod.org/ are licensed under a Creative Commons Attribution No-Derivative-Works Non-Commercial 3.0 License. by-nc-nd_3.0_80x15.png