Notices by Phil Stooke (philstooke@mastodon.social)

We'll start here:
Herschel, W., 1784. On the Remarkable Appearances at the Polar Regions of the Planet Mars, the Inclination of Its Axis, the Position of Its Poles, and Its Spheroidical Figure; With a Few Hints Relating to Its Real Diameter and Atmosphere. Philosophical Transactions of the Royal Society of London, v. 74, pp. 233-273. They liked long titles in those days. The paper includes these drawings among others, made starting in 1777. #maps #mars

This leads to the question: what was the first map of Mars? I will take the view that a single observation (photo or drawing) is not itself a map, but if several are set in some sort of coordinate framework, and/or combined into a composite image, and/or annotated in some way, they can become a map. Therefore I will state that in my view the first Mars map is by William Herschel (not Beer and Mädler as sometimes said) Let's see what Herschel did.

Time for a new theme. I have promised to do a sequence on Soviet lunar missions, but that will be the next one. It's been a long time since I've been to Mars - just about this time last year in fact, when I looked at Mars landing sites.

This time I want to follow a sequence of maps of Mars showing how our knowledge of the planet grew from the first Mars map to modern maps (a bit like the set of lunar farside maps I also did, early in 2024). #maps #mars

China's Chang'e 2 spacecraft mapped the Moon in support of later landings including a 7 m/pixel global photomosaic. Later it was redirected to fly past Toutatis. This is a composite of several images taken by a small monitoring camera. There are a few craters but as you can see most of the surface is undulating but not obviously cratered. The image is courtesy CNSA who luckily have adopted basically the same image use policy as NASA.

Let's look at those poles. The polar strips of the cylindrical relief map of asteroid Itokawa were projected into polar azimuthal projections and then images were mapped onto that base. Here is the north pole. #maps

Here is an image of asteroid 243 Ida with a lat-long grid added. The shape model was provided by Peter Thomas. My friend Maxim Nyrtsov was visiting and helped digitize the grid intersections and reproject them to intersections on a rectangular grid to make a photomosaic.