Venus
Earth’s twin
IV · Hidden Ground
Hidden ground
Visible light dies in the clouds.
Telescopes saw phases, then weather. Radar heard rock. Venera lasted minutes on the surface and sent photographs home. Magellan, 1990 to 1994, made the first global map of ground and gravity, and still is the atlas. The mystery is not only below the lid. Something in the upper cloud has no name yet.
Something in the upper cloud soaks up about half of the incoming ultraviolet sunlight. It has not been identified. NASA’s DAVINCI CUVIS instrument is designed to help name it. The mystery is not only below the clouds. It is inside them.
Recorded · the air as a wall
~42 km
Mariner 10 · 5 February 1974
On the way to Mercury the radio went through the clouds. The X-band signal died at about 50 km. The S-band reached about 42 km, then atmospheric absorption extinguished it. The lid is not only optical. It is thick enough to swallow a spacecraft’s voice.
Recorded · the archive that was still speaking
The point is not mystical hindsight. It is the scientific power of returning to evidence.
1991
February
Magellan records a nearly circular vent on the north flank of Maat Mons.
1991
October
The same vent has doubled and filled. The change is already in the tape.
1994
The craft is gone
The spacecraft is gone. The archive remains.
2023
Look again
Scientists look again. The volcano had been speaking the whole time.
Highland
The highest point on Venus, rising about 11 km. Named for James Clerk Maxwell, the only man among the goddesses on the map.
Continent
An Australia-sized highland in the north, crowned by Maxwell. Tessera here is a candidate for ancient crust. The name is IAU convention, not a claim about Akkadian religion on the ground.
Caldera
On Lakshmi Planum in western Ishtar Terra. A depression about 1 to 2 km deep and about 120 by 215 km across. Magellan’s published plate is about 420 km wide at the base. That 420 is the frame, not the patera’s own diameter. USGS lists the named feature at 233 km. Named for Sacagawea. Paterae: famous women.
Continent
The largest highland, sprawling along the equator. Ovda and Thetis Regiones fold into tessera, possible continental crust. Name is IAU.
Volcano
An 8 km shield volcano in Atla Regio. Magellan radar from February and October 1991 shows a vent that doubled in size and filled, consistent with an eruptive event. Reported from archival rereading in 2023. Open, and no longer only a candidate.
Recorded · the gazetteer
Venus has no moon. Maat Mons is a shield volcano in Atla Regio, approved by the IAU in 1982 from Pioneer-era radar. USGS origin: “Ancient Egyptian goddess of truth and justice.” Montes on this world are named for goddesses, Maxwell excepted. The name is older than Magellan. A letter from G. H. Pettengill to the Venus Task Group, 27 April 1977. The false satellite of the seventeenth century, later nicknamed Neith, is another Egyptian goddess and another error. It was never Maʿat.
Told · what Maʿat held
In Egyptian funerary religion the dead spoke in the Hall of Two Truths. Spell 125 of the Book of the Dead: declarations of innocence before forty-two assessors, one for each nome of Egypt. The heart was weighed against her feather. The list is not one sealed tablet. Copies differ. “Forty-two laws of Maat” is a later English name for those declarations.
Mythopoesis
The IAU did not name a volcano for forty-two. A later Book hears the number beside a mountain of truth. Hold the rhyme. Do not make the gazetteer prove the chronicle.
Rift rise
A volcanic rise split by Devana Chasma, a rift longer than the East African. Theia Mons sits on its flank.
Tessera
The first feature named on Venus, from early Earth-based radar. A tessera highland about 1.6 km above the surrounding lava plains, twice the size of Texas. DAVINCI is aimed here: possibly among the oldest surfaces, perhaps granitic. Open.
