2018 January 3
QUICKMAP – Latest Version Now Live
By selecting http://target.lroc.asu.edu/q3/, you will be directed to the Quickmap home page. As seen in Figure 1.
The slim menu bar on the left-hand side has changed in appearance, with a number of icons that expand by selecting them. The zoom control can be found at the top right hand corner. In the bottom left corner to the right of the ? symbol, you will see the lat/long data, and finally the scale bar is in bottom right.
The default projection as shown in Figure 1 is Orthographic (Nearside), but you can change this by clicking on the globe icon at the very top of the menu bar to open up the ‘Projections’ layer, as seen in Figure 2. When you click an icon on this new menu bar, the icon selected turns blue and the sub-menu pops out to the right. The fancy new function to try in the Projections sub-menu is the Lunar Globe 3D (last item on the sub-menu) which produces a 3D globe which you can twirl around using the mouse. The advantage of this function is that you can view any part of the surface even at high latitude without the distortion of perspective and from a simulated vertical position. You can still zoom in and out and use various functions and overlays available in the Layers menu (described below), but the feature names are no longer available. The star feature, however, of this 3D view is the ability to select a point and virtually fly around it. You do this by selecting the ‘Fly around selected point’ icon shown in Figure 3, which appears when you select the Lunar Globe 3D function. Once the icon is blue to show it is active, just click on the spot on the lunar globe you want to fly around, and a rather nice 3D simulation pops up flying around your chosen spot. The simulation can be a bit ‘jerky’ but is perfectly usable. To get back to the normal 3D globe view use the house icon below the ‘Fly around selected point’ one.
Figure 4 shows the next item on the menu bar, which is the ‘Layers’ icon of three horizontal bars. Clicking on this opens up a sub-menu with a number of individual layers starting with Overlays and ending at the bottom with LROC WAC Basemaps. Clicking each one of these layers opens up a sub-menu which contains various items. For example clicking on Overlays opens up a list running from Anthropogenic Features to Nomenclature. Each item on the list has a white box to the left, that turns green when you click in it activating that particular item, and an ‘i’ to the right. Clicking the ‘i’ (yes – it turns green when selected) opens yet another drop-down box which contains information, a sliding bar that allows you to alter the opacity of that item and in some cases a search function. So, to search for a particular named feature you would proceed as follows. Firstly click on Overlays in the Layers menu; from the list that drops down go to Nomenclature. If you simply click on Nomenclature (box to the left turns green when active) your lunar image becomes plastered with coloured dots marking the various surface features, all colour coded, and with the name attached visible when you zoom in. A single click on each dot brings up a box with the feature details from the Gazetteer of Planetary Nomenclature. To find a particular feature, however, click on the ‘i’ icon and a drop-down box appears containing the opacity slider, a key to all those coloured dots, and a search field. In the search field type in your feature name and press enter (it is case insensitive, but will not forgive spelling mistakes). Your results list pops up below, and by clicking your feature name the view will change to your target. For example, when searching for Gassendi, select the Nomenclature layer from the overlays sub-menu, you will notice that a green box will appear to the left of its name, showing that the layer is active, and the green ‘i’ to the right which has opened up the menu containing the opacity slider, key and search field below. You will see that all the features named Gassendi, such as satellite craters appear in the results and are marked with orange circles on the lunar image.
Heading down the list within Layers you come to a number of overlays that do not require an advanced knowledge of planetary science to understand, and are quite self-explanatory. Each one opens a sub-menu, and each item in the sub-menu has an ‘i’ icon on the right which reveals explanatory information.
Click the Clementine overlay for instance, and a sub-menu with 3 items appears, ‘UVVIS FeO Abundance (wt%)’, ‘UVVIS OMAT Map’, and ‘Clementine Colour Ratio’. These layers are extremely useful for studying the surface composition of the Moon and revealing the diverse rock types exposed by various processes. Fig. 5 shows two of the differing views available (remember the small ‘i’ icon on the side will open up a drop-down panel with more info) of the area around Messier and Messier A. The two images illustrate the variety of data available using the Clementine data in the Layers menu. The left panel shows Clementine UVVIS OMAT or Optical Maturity, which reflects the ageing of the surface due to space weathering (with the proviso that composition can sometimes compromise the data), and as can be seen, the rays which are fresh show up bright, as indeed do the inner slopes of the craters where down-slope movement exposes fresh, unweathered rock. The darker the shade the more time the surface has been exposed to weathering. The right panel shows Clementine Colour Ratio of the crater pair lying on the mare surface with the iron-rich basalt showing up in shades of yellow/oranges and blues. The highlands to the left edge of the frame show up as red indicating ancient anorthosite. The ray system of the pair is bright yellow, indicating fresh pulverised mare material excavated from beneath the mare surface. Top right shows the FeO content, with the mare showing up as bright due to the high iron content of the basalts, but note that the crater rays are slightly darker, suggesting a lower iron content possibly derived from a subsurface layer of differing composition.
Further surface data can be found in the Lunar Prospector layer, where Global Thorium abundance overlay can be found, whilst right at the bottom of the Layers menu TiO2 (Titanium Oxide) abundance overlays can be found in the LROC WAC Basemaps layer. Not much to see in the highlands with these overlays, but the maria show a mosaic of colours (or shades of grey if you go for the monochrome rendition) corresponding to different lava flows erupted at different times during lunar history. Figure 6 shows the same area around Messier as does Figure 5, and you can see that the crater rays are made up of low titanium material (dark blue) excavated from beneath a surface with a higher relative content of titanium. The colour coding key is accessed by selecting the ‘i’ icon.
The LROC WAC Basemaps layer also includes an option to see a WAC view with big shadows simulating a lunar sunrise. You lose the ability to zoom in quite as closely with this view, but subtle low amplitude features pop into view, especially on the maria when this view is active. If you like hunting for domes, this is your layer.
The LRO DIVINER layer provides more information on surface properties. The Standard Christiansen Feature Value provides information on the silicate polymerisation, with rocks derived from more polymerised melts being higher in silica, with low eruption rates and higher eruption viscosities as compared to less polymerised melts. Figure 7. Displays the Lassell Massif, showing the highly silicic rocks in dark blue. The surrounding mare is rusty red indicating higher amounts of the minerals olivine and pyroxene. The Massif is an area where ‘acid’ volcanism, that is volcanism where the lavas have a high silica content, has been identified. You can clearly see the dark blue colouration, which when compared to the key indicates a low CF value characteristic of this type of volcanism. Mons Gruithuisen Gamma and Delta also show up as dark blue indicating the presence of this exotic (for the Moon) type of volcanism. Once again the colour coding used in this overlay can be found in a key accessed by clicking the ‘i’ icon
The LRO DIVINER layer also has overlays displaying Nighttime Soil Temperatures and Rock abundance. To a degree they complement each other as rocky regolith retains the heat more efficiently during lunar night time and shows up warmer than less rocky regolith. Figure 8. Shows an area around Lichtenberg B with the Nighttime Soil Temperature layer active on the left, and Rock Abundance on the right. Note that the young Lichtenberg B is rocky and therefore retains heat more effectively during the lunar night. The Cold Spot to the north around a small fresh crater is visible in the left panel but is not evident in the Rock Abundance overlay on the right.
The correspondence is not exact, however, and recently identified ‘Cold Spots’ associated with the ejecta of small fresh impact craters show up only in the Nighttime Soil Temperature overlays. These overlays are very good at picking up the asymmetry in crater ejecta blankets, but only in young craters; the ejecta becomes indistinguishable in older craters as space weathering erodes the rocky component of the ejecta and reduces it to the same size as the surrounding regolith.
The GRAIL layer gives access to Bouguer gravity gradient overlays, such as the one shown in Figure 9. This ‘beneath the surface’ view shows that both Copernicus and Eratosthenes are perched on the submerged and highly shattered rims of much larger, older impact structures – a possible clue to their rather unusual central peak formations. Some of the explanations included in these sub-menus are not particularly helpful to the uninitiated, and are not a ‘beginners guide’ in any sense. In these cases it is best to search elsewhere for what these data overlays are telling you.
Moving down from the Layers menu you will find the Query Tool menu, indicated by an icon of a straight line with two dots at either end. This feature used to be in the top right hand corner of the old Quickmap. Clicking on it opens up a sub-menu with a line tool and polygon icon, as seen in Figure 10.
Select the line tool and using the mouse you can draw a line across the lunar image, and once you have done so a topographic profile appears in the Query Tools sub-menu (Figure 11). This profile is smaller and not quite as user-friendly as the version produced in the old Quickmap, but one useful feature is that as you draw your cursor along the profile, a red line appears on the profile and a dot on your line to show you exactly where that part of the profile is. Now, if you click on the line tool icon and draw another line across your feature, a second topographic profile will appear beneath the first one (your old line remains on the screen as well for reference) and in this way you can draw multiple profiles and view them all at once – you no longer have to draw them one at a time as you did with the old Quickmap, a major improvement.
Select the polygon icon and you can draw a polygon around your feature – the old Quickmap only let you draw a square. Once your polygon is in place click the down arrow opposite ‘Query feature’ in the sub-menu, and a list pops down with the various products you can choose. The old favourite of 3D Live allows you to create a 3-dimensional, rotatable model of your area, as shown in Figure 12.
There is a dustbin icon in the sub-menu, and if you click on it your recent lines or polygons disappear off the screen and you are ready to start again.
At the very bottom left-hand corner of the front screen is a small blue question mark. This allows you to report an issue with the program if you find one, but most usefully it has, under the ‘Recent Updates’ heading the option to download as a PDF a short instructional guide, see Figure 13. which covers the new version of Quickmap. It is not a complete A-Z in layman’s terms, but it is a help in understanding some of the features of this new version.
As noted at the beginning, you can quite happily explore the lunar surface in Quickmap without resorting to any of the multiple layers and overlays available. Dipping into the layers, however, reveals a wealth of data that a few years ago would have been only available to the professionals, making a deeper understanding of our satellite available to all.
|The British Astronomical Association supports amateur astronomers around the UK and the rest of the world. Find out more about the BAA or join us.|