Ventilator Diagrams Meet Lunar Cartography: An ItInsightsWorld Walkthrough of the CoVent-19 and Atlas of Space Workflows

Why engineers needed a ventilator primer

Translating a life-support device into a diagram a non-clinician can act on is as much an information-design problem as a medical one. That is the challenge behind the animation set published Last week, produced with Sarah Low — an anesthesiology resident at Massachusetts General Hospital and one of the leads of CoVent-19, one of many efforts responding to the ventilator shortage during the Covid-19 outbreak. The organization is run by thirteen medical doctors, and its purpose is to teach engineers the basics of medical ventilation, so that new ventilation solutions can be engineered from existing equipment or repurposed supplies.

Full background lives on the CoVent-19 website, and every one of these ventilation graphics has been released into the public domain, so readers are free to use them however they like. The scope is deliberately narrow, though: only the simplified circuits Sarah needed were illustrated, and the explainer is not a comprehensive treatment of ventilators.

The biological layer: where air meets blood

Before any circuit makes sense, the underlying physiology has to. Through tiny, air-filled sacs called alveoli, air moves from our lungs into the bloodstream — the exchange every ventilator design is ultimately trying to support.

Open circuit ventilators

At their simplest, these systems do not reclaim anything: waste gas is expelled from the circuit without recycling. That single rule defines the whole diagram.

Closed circuit ventilators

The second schematic sits much closer to a modern medical ventilator. Here air is recycled through a CO 2 filter to cut waste, while an outflow valve under the machine's control vents the pressure that accumulates as fresh air keeps being added to the closed system.

Building a geologic map of the Moon from six different datasets

The cartography half of this update covers the code tutorial for a geologic map of the Moon, still one of my personal favorites in the Atlas of Space body of work. It proved far harder than the geologic map of Mars made earlier, because the geologic data arrived split into six different datasets. Unique labels and, in places, different data formats meant a long stretch of time was spent piecing the material together into a single cohesive map.

Odd six datasets instead of one brought a second problem: the same geologic category could be worded differently in each file — “Basin Material, Rugged” against “Material of Rugged Basin Terrain”, for example — so closely related terms were folded into one shared color.

Chronology was the third obstacle. The lunar geologic timescales are imprecise: some units are stated with uncertainty, such as plains assigned to the “Imbrian or Nectarian” era, while other categories bundle many periods together, such as craters dated to “Imbrian, Nectarian, and pre-Nectarian” time. Rendering every uncertain aggregation would have overloaded a single map, so timescale data was dropped entirely and features are colored only by geologic category — craters, basins, and the like — never by age.

Styling drew on the past rather than the present. The source maps were first published in the 70’s, and their bright neon color schemes were worth keeping; as many original hues as possible were retained, then rearranged so the most extreme colors were reserved for smaller or more unusual geologic formations.

What ships as a result is a summarized geologic map, not a precise replication of the underlying data. Geologic features were merged and the scientific labels were simplified, so the map is asked to do one job only: act as a condensed overview of Moon geology.

Four landmarks are annotated on the surface: Mare Orientale, a huge impact crater on the far side of the moon; Mare Tranquillitatis, the landing site of Apollo 11, the first manned landing on the Moon; the far side of the moon itself; and Fra Mauro crater, sitting at center next to the neon green Fra Mauro highlands — the landing site of Apollo 14 in 1971.

This sheet is also the final installment of the Atlas of Space run. Working with astronomy data has been a genuine pleasure and more maps will surely follow, but for now the priority is finishing the last PhD research project. Thanks are due for all of the comments and suggestions this summer — sharing these maps has been the highlight of the season. For anyone heading to the NACIS meeting this fall, there will be more on this work in the Using Open Data panel.

Credits behind the geologic map

Data

Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU). © 2019 Working Group for Planetary System Nomenclature (WGPSN).
Planetary Symbology Mapping Guidelines, Federal Geographic Data Committee.
LRO LOLA Elevation Model 118m (LDEM GDR). © 2018 NASA PDS and Derived Products Annex. LOLA Science Team.
Lunar 5M Geologic Map Renovation. NASA PDS and Derived Products Annex. © 2016 USGS Astrogeology Science Center.
Missions to the Moon. © 2019 The Planetary Society.

Reference texts

Astronomy, Andrew Fraknoi, David Morrison, Sidney C. Wolff et al. © 2016 OpenStax.

Fonts

Map labels are typeset in Moon by Jack Harvatt; the title font is RedFlower by Type & Studio.

Advice

With thanks to Henrik Hargitai, Oliver Fraser, Michael Ruxton, Chloe Pursey, and Leah Willey for their helpful advice in making this map.

The companion sheets: topography alongside geology

Two maps in the Atlas of Space series treat the Moon's topography and geology together, and they came out of some of the most rewarding datasets in the project. The Moon is our closest celestial neighbor, and we know considerably more about it than about the neighboring planets — several hundred kilograms of lunar rock were returned to the Earth by the Apollo missions for detailed analysis alone.

The viewing geometry is dictated by tidal locking: the Moon completes one rotation around its axis in exactly the time it takes to circle the Earth, so the far side of the moon is never visible from the Earth's surface. On this topographic map the near side of the moon fills the large central panel, while the North pole, South pole, far side and interior are laid out across the four surrounding maps.

Human attention to this body is not new: for thousands of years people have tracked lunar events, and a full moon or an eclipse remains tied to ancient calendars, myths and celebrations. The cycle now shows up in digital traces too — Google searches for the word “moon” peak predictably at every full moon.

The supporting annotations read as follows: 1, the data layers used to design this map; 2, Google search frequency for the word “moon” in the United States, built from Moon phase dates and Google Trends, where each yellow line is one lunar cycle in 2018 normalized to the highest and lowest value within that cycle, and the turquoise line marks the overall mean.

Credits behind the topographic map

Data

Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU). © 2019 Working Group for Planetary System Nomenclature (WGPSN).

Reference texts

Fonts

Map labels are typeset in Moon by Jack Harvatt; the title font is RedFlower by Type & Studio.

Advice

With thanks to Oliver Fraser, Henrik Hargitai, Chloe Pursey, and Leah Willey for their helpful advice in making this map.

What both projects share

Set side by side, the ventilator explainer and the lunar sheets follow the same editorial logic: strip a system to the components the audience actually needs, disclose what was merged or omitted, and leave the sources visible so anyone can rebuild the picture. Whether the subject is gas moving through a closed breathing circuit or terrain redrawn from six source files, the deliverable is the same — a readable model of something most people will never inspect directly.