Tag: Mars

New Gravity Map of Mars Reveals Subsurface Variations

Published on by Jonathan Crowe
Gravity map of Mars. The red circles show prominent volcanoes on Mars and the black circles show impact crates with a diameter larger than a few 100 km. A gravity high signal is located in the volcanic Tharsis Region (the red area in the centre right of the image), which is surrounded by a ring of negative gravity anomaly (shown in blue).
Gravity map of Mars, from Root et al.

A study presented earlier this month at the Europlanet Science Congress maps the variations in Mars’s gravitational field.

Dr Root and colleagues from TU Delft and Utrecht University used tiny deviations in the orbits of satellites to investigate the gravity field of Mars and find clues about the planet’s internal mass distribution. This data was fed into models that use new observations from NASA’s Insight mission on the thickness and flexibility of the martian crust, as well as the dynamics of the planet’s mantle and deep interior, to create a global density map of Mars.

The density map shows that the northern polar features are approximately 300-400 kg/m3 denser than their surroundings. However, the study also revealed new insights into the structures underlying the huge volcanic region of Tharsis Rise, which includes the colossal volcano, Olympus Mons.

Abstract, press release, Universe Today.

Previously: New Gravity Map of Mars.

A Martian Mosaic at Five Metres per Pixel

Published on by Jonathan Crowe

Global CTX Mosaic of Mars (screenshot)

The Global CTX Mosaic of Mars, produced by CalTech’s Bruce Murray Laboratory for Planetary Visualization, is a 5.7-terapixel mosaic of the Martian surface at a resolution of five metres per pixel. The mosaic is available in a number of different formats (via ArcGIS Online, KML, shapefiles), as well as via this online viewer; and the Lab is quite transparent about how they constructed it from Mars Reconnaissance Orbiter Context Camera (CTX) data. [Maps Mania/La Cartoteca]

An SF/Fantasy Map Roundup

Published on by Jonathan Crowe

In December Tor.com revealed the map for Martha Wells’s upcoming fantasy novel, Witch King, which comes out in May. The post includes both Rhys Davies’s map and Wells’s initial sketch: compare and contrast. Amazon (Canada/UK) | Bookshop

How often do Star Trek tie-in novels come with maps? John Jackson Miller’s Strange New Worlds novel, The High Country, which comes out today, includes maps of the low-technology world on which it is set; in Miller’s Twitter thread last month, he wondered whether his book was the first, but it turns out that a 2000 Deep Space Nine novel also had maps. Amazon (Canada/UK) | Bookshop

In my article about maps in science fiction I made reference to the maps in Kim Stanley Robinson’s 1993-1996 Mars trilogy. Mastodon user 65dBnoise decided those maps were “very few” and “very coarse” (he’s not wrong1) and made some higher resolution maps based on USGS topographical maps of Mars.

Large-Scale Geologic Maps of Mars

Published on by Jonathan Crowe

Geologic Map of Olympus Mons Caldera, Mars (USGS)
Geologic Map of Olympus Mons Caldera, Mars. USGS SIM 3470.

The USGS’s Astrogeology Science Center highlights three geologic maps of Mars released in late 2021. The maps are large-scale, focusing on specific Martian features (e.g. Olympus Mons, above).

Though maps have historically covered large areas, with crewed lunar missions on the horizon and other missions across the solar system in the planning stages, large-scale, small-area maps are starting to steal the limelight. These large-scale, small-area maps provide highly detailed views of the surface and allow scientists to investigate complex geologic relationships both on and beneath the surface. These types of maps are useful for both planning for and then conducting landed missions.

The maps are of Olympus Mons Caldera, Athabasca Valles and Aeolis Dorsa. Interactive versions, with toggleable layers over spacecraft imagery, are also available: Olympus Mons Caldera, Athabasca Valles, Aeolis Dorsa.

Mapping the Shoreline of an Ancient Martian Ocean

Published on by Jonathan Crowe

3D map showing evidence of ancient Martian shoreline
Benjamin Cardenas/Penn State (Creative Commons)

“A recently released set of topography maps provides new evidence for an ancient northern ocean on Mars. The maps offer the strongest case yet that the planet once experienced sea-level rise consistent with an extended warm and wet climate, not the harsh, frozen landscape that exists today.” Press release, video, article (JGR Planets). [Universe Today]

Mapping the Watery Past of Mars

Published on by Jonathan Crowe

ESA

A new map of Mars reveals the abundance of aqueous minerals—clays and salts that form in the presence of water—that were created during the planet’s distant watery past. “The big surprise is the prevalence of these minerals. Ten years ago, planetary scientists knew of around 1000 outcrops on Mars. This made them interesting as geological oddities. However, the new map has reversed the situation, revealing hundreds of thousands of such areas in the oldest parts of the planet.”

A Mars Map Roundup

Published on by Jonathan Crowe

Nathaniel Green's map of MarsNational Geographic looks at the rivalry between two early cartographers of Mars who based their maps on observations made during Mars’s “Great Opposition” in 1877: Nathaniel Green, whose Mars “was a delicately shaded world with landforms that gradually rose from vast plains and features that blended into one another” (pictured here) and Giovanni Schiaparelli, whose Mars had more detail—including those famous canals—but was less accurate.

A new study maps the possible locations of subsurface water-ice reservoirs, vital for any crewed missions. [Sky & Telescope]

Kenneth Field’s virtual globe of Mars follows in the footsteps of his 2016 map.

Interactive maps showing the locations and paths of the Curiosity and Perseverance rovers. [Maps Mania]

Fifteen Ways to Depict Elevation on Mars

Published on by Jonathan Crowe

How do you depict elevation on a map of Mars? Earlier this year, Daniel Huffman posted a roundup of hypsometric tints for Mars.

I have a peculiar hobby of collecting Martian hypsometric tinting schemes: those sets of colors that cartographers use to depict elevations on the Red Planet. It’s a fascinating cartographic frontier. While the classic (and somewhat flawed) way of showing Earth’s elevations is to use a color scheme that starts with green lowlands, and then proceeds through some combination of brown/yellow/orange/red until it reaches white in the highest areas, there’s no standard yet for Mars. Maybe centuries from now, one of the schemes below will become that standard.

Huffman looks at fifteen schemes in total in the post, and in this video on YouTube:

Digital Museum of Planetary Mapping

Published on by Jonathan Crowe

Camille Flammarion, “Mappemonde géographique de la planète Mars,” Terres du Ciel, 1884.

The Digital Museum of Planetary Mapping is an online collection of maps of the planets and moons of our solar system. There are more than two thousand maps in the catalogue, some dating as far back as the 17th century, but the bulk of them, understandably, are much more recent; also understandably, Mars and the Moon are the subject of most of the maps (40 and 46 percent, respectively).

The site is more like a blog than a library catalogue: it’s powered by WordPress and the individual listings are blog posts, but that’s perfectly legitimate, albeit less elegant. (But then who am I to judge?)

The project was presented at the European Planetary Science Congress in Berlin last month: for news coverage, see Phys.org and Space.com; the press release is here. [WMS/WMS]

Moons and Planets added to Google Maps

Published on by Jonathan Crowe

Google Maps (screenshot)

The Moon and Mars were relatively early additions to Google Earth; that application may have been migrated to the web, but the planets and moons keep coming. Yesterday Google announced the addition of a dozen other worlds in our solar system; the space layer of Google Maps now includes planets Mercury, Venus and Mars; dwarf planets Ceres and Pluto;1 Jupiter’s moons Io, Europa and Ganymede; and Saturn’s moons Dione, Enceladus, Iapetus, Mimas, Rhea and Titan. Large moons Callisto and Triton aren’t included, and Iapetus is projected onto a sphere rather than appearing as the bizarre space walnut it is.

The Planetary Society’s Emily Lakdawalla noticed a thing, though:

Emily reports that this bug affects several moons of Jupiter and Saturn; Google is apparently already on it and may have fixed it by the time you read this.

New Gravity Map of Mars

Published on by Jonathan Crowe

NASA/Goddard/UMBC/MIT/E. Mazarico

A new gravity map of Mars that shows the thickness of the Martian crust based on gravity measurements from Martian orbiters, reveals a crust that is less dense and shows less variation than earlier maps. “The researchers mapped the density of the Martian crust, estimating the average density is 2,582 kilograms per meter cubed (about 161 pounds per cubic foot). That’s comparable to the average density of the lunar crust. Typically, Mars’ crust has been considered at least as dense as Earth’s oceanic crust, which is about 2,900 kilograms per meter cubed (about 181 pounds per cubic foot).”

A Globe of Percival Lowell’s Mars

Published on by Jonathan Crowe

pkm-mars-globe

Hand-made globes are increasingly a thing, apparently. As Atlas Obscura reports this week, Michael Plichta’s company, Planetenkugel-Manufaktur, is producing a hand-crafted globe of Mars with a twist: it’s based on Percival Lowell’s maps, which (erroneously) showed the Martian surface covered in canals. It’s delightfully retro and I love it. Here’s a video:

Nowhere on the website is a price mentioned, which tells me that I won’t be able to afford one, damn it.

An Ordnance Survey Roundup

Published on by Jonathan Crowe

mars-symbol

  • Concomitant with the Survey’s map of Mars was a competition to design a map symbol to represent landing sites. The winner has been announced: the OS will use Paul Marsh’s symbol, which incorporates the Mars symbol with landing gear, on its Mars maps in the future.

Map Contest: Proposed Mars Landing Sites

Published on by Jonathan Crowe

The ICA’s Commission on Planetary Cartography has put out a call for maps of the 47 proposed exploration zones on Mars.

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.

More at the ICA and All Over the Map. [Leventhal/WMS]