A new online atlas of artificial sky brightness is now available, based on updated light pollution data published last week. (There’s also a 3D globe version that may not work in all browsers.) Light pollution, as I’ve blogged before, is the bane of professional and amateur astronomers alike, obscuring fainter objects and interfering with observations, both naked-eye and through telescopes. As the article in Science Advances puts it, “This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans.” [Rumsey Map Center]
- Scottish newspaper The Courier has a somewhat belated piece on the 80th anniversary of the Ordnance Survey’s trig pillars.
The project is to select one candidate landing site and design an actual map that you envision will be useful in surface operations. We ask that you do not create simply a geologic map, but rather a product that can be used by the astronauts during their approximately one-year long mission within the Exploration Zone. This requires creativity, and it is also useful to have a good knowledge of surface features, surface hazards, science goals and the use of the proper cartographic tools.
The contest is open to students, young professional cartographers, and graphic artists in any country of the world.
Catholic News Service: “Of the many momentous or menial tasks women religious perform, one of the better-kept secrets has been the role of four Sisters of the Holy Child Mary who were part of a global effort to make a complete map and catalog of the starry skies. […] Sisters Emilia Ponzoni, Regina Colombo, Concetta Finardi and Luigia Panceri, all born in the late 1800s and from the northern Lombardy region near Milan, helped map and catalog nearly half a million stars for the Vatican’s part in an international survey of the night sky.” [@CUATheoPhilLib]
The first complete topographic map of Mercury, based on data from the MESSENGER mission, was released last Friday: MESSENGER, USGS. The version above is a Robinson projection without labels (Robinson with labels, global DEM). “Mercury’s surface is colored according the topography of the surface, with regions with higher elevations colored brown, yellow and red, and regions with lower elevations appearing blue and purple.” [GIS and Science, The National Map]
An updated map of Pluto now includes lower-resolution imagery from earlier in New Horizons’ approach. “The map includes all resolved images of Pluto’s surface acquired between July 7-14, 2015, at pixel resolutions ranging from 18 miles (30 kilometers) on the Charon-facing hemisphere (left and right edges of the map) to 770 feet (235 meters) on the hemisphere facing New Horizons during the spacecraft’s closest approach on July 14, 2015 (map center). The non-encounter hemisphere was seen from much greater range and is, therefore, in far less detail.” See coverage from Universe Today and Wired (the latter has a nice loupe feature on the map).
NASA also released an elevation map of the area around Sputnik Planum (the left side of the heart-shaped feature).
Previously: New Maps of Ceres and Pluto.
Kenneth Field’s map of Mars (note updated link) now includes an option to add oceans, with checkboxes to fill the landscape to various elevations.
You can irrigate the planet below the areoid on this map using the water layers. You’ll notice the water layers aren’t blue. On Earth, water appears blue due to red, orange, yellow and green wavelengths of light being absorbed more strongly than blue and also the reflectence of the blue sky. Since Mars has relatively little atmosphere and it’s farther from the sun it’s likely water will appear differently. We’re imagining wavelengths will be absorbed differently, perhaps returning an alien green?
Previously: Kenneth Field’s Map of Mars.
Postdoctoral researcher Oliver White talks about creating maps of Pluto’s geology from New Horizons flyby imagery.
I have studied this area in great detail, and have defined each unit based on its texture and morphology—for example, whether it is smooth, pitted, craggy, hummocky or ridged. How well a unit can be defined depends on the resolution of the images that cover it. All of the terrain in my map has been imaged at a resolution of approximately 1,050 feet (320 meters) per pixel or better, meaning textures are resolved such that I can map units in this area with relative confidence.
By studying how the boundaries between units crosscut one another, I can also determine which units overlie others, and assemble a relative chronology (or timeline) for the different units; this work is aided by crater counts for the different terrains that have been obtained by other team members. I caution that owing to the complexity of the surface of Pluto, the work I’ve shown is in its early stages, and a lot more is still to be done.
Previously: Mapping Pluto’s Geology.
As part of its regular “Map Monday” feature, Atlas Obscura looks closely at Frederick de Wit’s Planisphærium cœleste (1670), above. Like other celestial maps of the period, it’s as though the monsters on sea charts have been placed in the skies—especially true for constellations like Cetus, as the article shows.
This reminds me that there’s quite a lot about antique celestial maps in The Map Room’s archives: The Face of the Moon; Star Atlases; Historical Celestial Atlases on the Web; The U.S. Naval Observatory’s Celestial Atlases; Divine Sky: The Artistry of Astronomical Maps; Another Look at the Linda Hall Library’s Celestial Atlases; Christian Constellations.
Previously about Frederick de Wit: A New Book About Frederick de Wit.
Daniel Macháček released his topographic map of Mars, based on the latest probe data, in November 2014. It uses the Mercator projection between 65° north and 65° south latitude and stereographic projections for the poles. It can be downloaded in insanely high resolution: 17,400×14,700 (78 MB JPEG, 106 MB PDF). His blog post (in Czech: use the translate button) has all the technical details. I particularly like the colour scheme he used for elevation data: the low-lying areas are coloured like deep oceans, which seems appropriate. [Maps on the Web]
(Globe gores for other planets and moons are available for download from the USGS’s Astrogeology Science Center.)
Previously: Globes of the Solar System.
Because of its thick and opaque atmosphere, Titan’s largest moon, Titan, has to be mapped piece by piece during close fly-bys by the Cassini spacecraft, using radar, infrared and visual data. The above image is one of two montages that “shows four synthetic views of Titan created using data acquired by the visual and infrared mapping spectrometer (VIMS) on board NASA’s Cassini spacecraft between 2004 and 2015. These views demonstrate some of the progress researchers have made in creating smooth-looking maps of Titan from the multitude of different VIMS observations made under a wide variety of lighting and viewing conditions.” More on VIMS here.
A new gravity map of Mars, based on data from three orbiting spacecraft, has been released. “Slight differences in Mars’ gravity changed the trajectory of the NASA spacecraft orbiting the planet, which altered the signal being sent from the spacecraft to the Deep Space Network. These small fluctuations in the orbital data were used to build a map of the Martian gravity field.”
The data enables the crustal thickness of Mars to be determined to a resolution of approximately 120 kilometres. Here’s a short video explaining the significance: