#Tag · 𑐴𑐶𑐟𑐶

The Old Map Gallery @oldmapgallery@sciencemastodon.com · last week

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Holy cow...
So nice!!
When you get a minute to explore. It's amazing for showing our solar system, but also for the bigger context
https://atlasof.space/

#maps #space #map

Phil Stooke @PhilStooke@mastodon.social · 2 weeks ago

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Finally - Amazonis. The name makes us think of the Amazon in Brazil, but originally it was the name of a female warrior society whose tales crop up all over the place in classical contexts. Amazons fought on the side of Troy in the Trojan war and are usually associated with northern Turkey.

OK, enough names. Now we will return to our sequence of Mars maps. #maps #Mars

Amazonis Planitia on Mars is named after the Amazons, a female warrior society who fought in the Trojan War, on the side of Troy. They are associated with a lot of places in the region but especially with northern Turkey. The modern use of the name in Brazil is not connected with the ancient stories except that Spanish soldiers claimed to have encountered female warriors in the area.

Phil Stooke @PhilStooke@mastodon.social · 2 weeks ago

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Next, Utopia, where Viking 2 landed in 1976. Unlike all those other names, this is not ancient and comes from Thomas More's book of 1516. It literally means 'nowhere' and is used for a perfect place or society (maybe so perfect it couldn't really exist). In the book it was an island out in the Atlantic near the Americas.This name is not on Schiaparelli's map and probably comes from Flammarion and Antoniadi's map of 1900. #maps #Mars

Utopia on Mars is where Viking 2 landed in 1976. But it's not a real place and not a classical name - it was invented in 1516 by Thomas More and literally means 'nowhere'. It refers to a place so perfect it couldn't really exist.

Phil Stooke @PhilStooke@mastodon.social · 2 weeks ago

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After that rather long excursus into Martian nomenclature we return to the sequence of Mars maps. Looking back, we saw maps of light and dark markings, at first barely glimpsed through telescopes, but evolving into quite sophisticated drawings - Green's map is quite realistic though others seem more sketchy. Schiaparelli saw lines ('canali') and Proctor rendered them as rivers. From 1890 to about 1930 many maps showed canals, which we now discount. #maps #Mars

Phil Stooke @PhilStooke@mastodon.social · 2 weeks ago

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In the middle of the 20th Century canals had fallen into disfavour. Typical maps of the 1950s, such as the International Astronomical Union (IAU) map drawn by Glauco de Mottoni y Palacios in 1957 as a key to official nomenclature, showed broad light and dark areas similar to Green's map. Here it is stripped of names (by cloning) and transformed to my common projection. Nothing suggesting topography or geology is visible. Don't be fooled by assertions that some people saw craters. #maps #Mars

A map of Mars drawn in 1957, just before the Space Age began, by Glauco de Mottoni y Palacios for use as a key to nomenclature. It shows subtle light and dark markings resembling those illustrated by Nathaniel Green (shown earlier in our sequence). No topography is visible.

Phil Stooke @PhilStooke@mastodon.social · 2 weeks ago

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That last map was drawn in the year of Sputnik. Direct exploration by spacecraft was not far off, so NASA needed a new map. The job went to the US Army and Air Force, who both had large mapping agencies and were gearing up for Moon mapping. I will show the Air Force map. You can see it here:

https://www.lpi.usra.edu/resources/mars_maps/MEC-1/

Look at that - it has canals! So did the less aesthetically pleasing Army maps. It's a curious footnote of Mars mapping history. #maps #Mars

Phil Stooke @PhilStooke@mastodon.social · 2 weeks ago

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Here I add my manipulated version of it for easier comparison with the others. Look at the original - it's north up, not south up. The old astronomical convention was dropped. Longitudes go from 0 to 180 east and west from the prime meridian (still using the 1840 version of zero longitude). Our familiar names are on display. Compare Syrtis Major's longitude here and on the previous map - this one is 10 degrees too far east. Oops! #maps #Mars

A map of Mars made for NASA in 1962 (this is a later printing of it) by the US Air Force. The original has been stripped of text and transformed to an azimuthal projection.

Phil Stooke @PhilStooke@mastodon.social · 4 weeks ago

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No - Schiaparelli saw Mars like this - with south at the top. Until the dawn of the space age most planetary maps were drawn with south at the top as seen in an inverting astronomical telescope. Only when maps might be used for direct physical exploration did the convention change to avoid potential confusion. Rather than turn our screens upside down, let's do a 'rotate 180 degrees' in Photoshop. Simples! #maps #Mars #Hubble

This is the previous Hubble Space Telescope image turned upside down to match the view from a astronomical telescope, which inverts the image.

Phil Stooke @PhilStooke@mastodon.social · 4 weeks ago

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We need a bit of a mind-flip to understand how Schiaparelli developed his naming scheme. We start with a map of Mars - let's use a modern one from the Hubble Space Telescope. But Schiaparelli didn't see Mars like this... #maps #Mars #Hubble

A map of Mars made by combining several images taken by the Hubble Space Telescope into a cylindrical projection. The poles are cloudy but the rest of the planet has its characteristic orange colour (iron oxides) with various darker markings.

Phil Stooke @PhilStooke@mastodon.social · 4 weeks ago

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Now we need to look back in time to the classical understanding of the world. How better to do that than with Ptolemy's map of the world known to him at the time? None of Ptolemy's maps survived into the medieval world, but his list of places - a sort of gazetteer - did. 8000 places with his estimates of their latitude and longitude, from which his maps have been reconstructed. See the similarity? No, nor do I, but Schiaparelli found a way to link them. #maps #Mars #Ptolemy

A map of the world (as know to him) by Claudius Ptolemaeus, or Ptolemy, c. the year 150. It didn't survive but has been reconstructed from lists of places and their latitude and longitude.

Phil Stooke @PhilStooke@mastodon.social · 4 weeks ago

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And here it is. A Hubble image of Mars and a 19th Century drawing, both with south at the top. Astronomers had observed a roughly circular marking with a central dark spot. Schiaparelli made it the place where Helios would begin his journey over the planet, distributing names as he went. He named it Solis Lacus, the Lake of the Sun. The modern feature Solis Planum is inside it. #maps #Mars #Shiaparelli

A Hubble Space Telescope image of Mars and a 19th Century drawing of the planet, both showing a circular marking with a dark spot at its centre, resembling he Sun symbol.

Phil Stooke @PhilStooke@mastodon.social · last month

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I answered my first map question in a separate post. Back to Herschel: his map has no coordinates but coordinates can be approximated. I projected the Herschel map into a cylindrical projection and then into two equator-centred azimuthal projections making the best match I could to modern coordinates. My intention was to take a variety of historical and recent maps in different projections and display them all in a common format for comparison. #maps #Mars #Herschel

William Herschel's map of Mars reprojected into an equator-centred pair of azimuthal projections, roughly matched to modern coordinates.

Phil Stooke @PhilStooke@mastodon.social · last month

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Here is Herschel's actual map (left). I compare it with a mid-20th Century map in the same projection (azimuthal, extending from the south pole at centre to the mid-latitudes in the northern hemisphere). There's no coordinate grid but it vaguely resembles the more modern map. It's the first map of Mars, but not the first map of another planet. Anyone care to speculate who made the first map of another planet, and which one? #maps #Mars #Herschel

William Herschel's 1784 map of Mars (left) and a mid-20th Century map in the same (approximate) geometry (right). I will identify the more modern map when we get to it in the sequence.

Phil Stooke @PhilStooke@mastodon.social · last month

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The next stop on our history of Mars mapping is the German astronomers Beer and Mädler. Working in the 1830s and 40s, they took Mars maps a significant step further, establishing a coordinate system and a prime meridian which is essentially what we use today. Here is the map made from observations in 1830 (published 1831) when the southern hemisphere was visible (as for Herschel). The south pole in in the middle, 30 north at the outer edge. #maps #Mars #Beer #Mädler

A map of Mars made in 1830 by German astronomers Beer and Mädler. it shows the south pole at the centre and 30 degrees north at the outer edge in an interrupted azimuthal projection.

Phil Stooke @PhilStooke@mastodon.social · last month

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This map is what you get if you transform the Beer and Mädler map into the same projection I used for Herschel a few posts ago. Both polar azimuthal maps were transformed to cylindrical and combined to give global coverage (taking the opportunity to fix that pesky mistake), then transformed again to an equator-centred azimuthal equidistant projection. Now it gets a bit easier to compare with modern maps. #maps #Mars #Beer #Mädler

The Beer and Mädler map of the previous post is shown here in another azimuthal projection, this time centred on the equator in two hemispheres.

Phil Stooke @PhilStooke@mastodon.social · last month

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In 1841 Beer and Mädler published a map of the whole planet after the north pole became visible later in the 1830s (it all depends which pole is tilted towards us when Mars is closest to Earth). They stuck with polar projections which led them into a clumsy mistake. I'm just glad I'm not the only one - you can't be out there as much as I am without making public mistakes. Look at the longitude of feature 'f' (= Syrtis Major) in the two hemispheres. One (north) is wrong. #maps #Mars #Beer #Mädler

Mars mapped by Beer and Mädler in 1841. The whole planet is shown in two pole-centred hemispheres. Splitting the map at the equator caused a mistake. A feature labelled 'f' (it is what we would call Syrtis Major) is at about longitude 70, but in their northern hemisphere it is at about 100 degrees. Mädler drew the map, and he must have kicked himself when he noticed.

Phil Stooke @PhilStooke@mastodon.social · last month

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Do these features match things we see today? (a faithful reader asks). Yes, and here are a few names - the traditional telescopic feature names like Meridiani Sinus (Sinus = Bay), not the modern topographic names like Meridiani Planum (Planum = plateau), though they are obviously related. And Meridiani refers to the dark spot Beer and Mädler chose to mark the prime meridian.

These maps are from my first Mars atlas. I won't show every historic Mars map, just a few interesting ones. #maps #mars

This is the map in the previous post with some feature names added to help orient yourself.

Phil Stooke @PhilStooke@mastodon.social · last month

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Here is a modern (i.e. Cassini) map of Rhea with feature names:

https://asc-planetarynames-data.s3.us-west-2.amazonaws.com/rhea_comp.pdf

If you want to explore all such solar system names, go here:

https://planetarynames.wr.usgs.gov/

Use the menu bar underneath the banner image to explore names on maps of many worlds. You will notice asteroids are included. But interestingly, for some reason, not comets. I don't know why not. Even Rosetta's amazing comet 67P, which did get names in publications, never got official status for them. #maps #planets