Lab 6: Lunar Observing

Lab 6: Lunar Observing

Name: ______

Lab Partner(s): ______

Section: ______

The purpose of this lab is to discover and interpret some of the variety of features visible on the lunar surface. Although the questions in this lab cannot possibly cover all of these, we hope that they will pique your interest, and that this lab will give you the tools you need for many hours of lunar observing enjoyment.

The first view which one obtains on looking at the moon through a telescope is very likely to create the impression that the lunar surface consists of nothing more than a few comparatively smooth areas and a hopeless jumble of circular objects called craters. Prolonged observation and scrutiny of small regions, however, reveals great walled plains, ring mountains, multiple craters, chains of craterlets, valleys and clefts, mountain ranges, isolated peaks, and long, white ray systems. Each investigation rewards the observer with new surprises. One has a whole world to explore and interpret.

There are several terms with which you should be familiar to complete this lab. The terminator is the dividing line between illuminated and unlit parts. In other words, it is the dividing line between day and night as observed from a distance. The limb is the outer edge of the Moon. A convex boundary is one that curves or bulges outward, like the outside of a circle. A concave boundary, on the other hand, is one which curves like the inside of a circle.

When making your observations, use whichever eyepiece is appropriate for the feature in question. Also, the positions of significant features should be marked on the map(s) provided. Backup your statements with evidence! Any unusual formations which you notice should be described and sketched in question #22 of this lab.

(1) Using your lowest magnification, sketch the overall general appearance of the moon.

(2) Look for the large smooth surfaces which Galileo called “maria” (seas). These large

plains are now known to be the end result of large lava flows. Are the lunar plains

connected with one another?

______

______

(3) What is the general shape of the maria? Color? ______

______

(4) In which quadrants of the moon do the maria predominate? (NE, NW, SE or SW)

______

______

(5) Estimate the proportion of the visible surface covered by the plains. ______

______

______

(6) Estimate the diameter of Mare Serenitatis, knowing that the moon's diameter is about

3500 km. Show your work!

______

______

______

(7) Do the maria contain any craters? Elaborate. ______

______

______

(8) Sketch in detail an example of a region where a mare and the highlands (i.e. plains)

are connected (i.e. a “sea shore”). Mark its position on the map.

(9) Locate regions within the maria which are distinctly darker in color than the general

tone of the maria, and sketch/label these on the map.

(10) Craters range in size from hundreds of kilometers down to less than a millimeter (as

found by the Apollo astronauts). In general, which wall of the craters is steeper, the

inner or the outer? Why might this be so? ______

______

______

(11) Are craters more easily visible near the limb or near the terminator? Why?

______

______

______

(12) As a rule, do the crater floors appear to be level with, above, or below the general

level of the surrounding region? Locate examples on the map and label.

______

______

______

(13) Do all large craters have peaks in the center? Do the central peaks ever show

depressions at their summits?

______

______

______

(14) Based upon your observations, is there evidence for volcanoes and/or volcanism on

the moon? Discuss.

______

______

______

______

(15) Locate and sketch a small region where one or more craters are deformed by

another. Mark its position on the map.

(16) Identify the youngest craters in your map.

(17) The three largest mountain ranges on the near side of the moon are the Appennines,

the Caucasus, and the Alps. In general, are lunar mountain ranges straight or curved?

______

______

______

(18) For those mountain ranges that are curved, is the steeper side on the convex or

concave side? Is this similar to that of the lunar crater walls? ______

______

______

______

(19) In general, how do the mountains compare to the maria in terms of their color?

______

______

(20) Find and sketch some typical rills (what appear to be dry river beds). Mark the

position of these features on the map.

(21) Find and sketch an example of a partially-submerged crater.

(22) Using a high magnification, make as detailed a sketch as possible for a very small

region of your choice.

(22) Describe any other features which you have discovered.

______

______

______

______

______

______

The Mare Serenitatis

References: