The most comprehensive catalogue of volcanoes ever compiled for Venus, and probably for any planet, anywhere has been released. This work is the result of years of hard work by Rebecca Hahn, the study’s lead author and senior graduate student at Washington University in St. Louis.
More than 85,000 individual volcanic landforms, were mapped with decades-old radar imagery from NASA’s Magellan mission – about 99% of these edifices are <5 km in diameter; There appears to be a lack of edifices in the 20–100 km dimeter range.
“This new database will enable scientists to think about where else to search for evidence of recent geological activity,”
When asked “Which ones are active?”, Paul answered “Pretty big question, which we can’t answer… yet.”
One of the things I noticed in the paper is how “an automated approach” was used to do the mapping. I thought this tied-in nicely with this summer’s Vatican Observatory Summer School theme – which is tools and methods used to process large datasets.
“In this study, we utilized the freely available ‘hdbscan’ Python package to identify clusters of shield volcanoes as an automated approach to mapping volcanic fields.”
from the paper
This makes me wonder what other hidden treasures await discovery in historic space mission data archives?
Venus Volcano Map (with legend)
Image Caption: Figure 5. Our completed global survey of volcanic edifices and volcanic fields on Venus. This survey includes 32,512 volcanic edifices <5 km in diameter (aqua triangles), 51,660 edifices <5 km in diameter for which only geographic coordinates were recorded because of locally poor radar image quality (teal triangles), 729 edifices 5 – 100 km in diameter (pink triangles), 118 edifices >100 km in diameter (orange triangles), and 182 edifices (of all diameters) that show evidence for gravitational deformation (purple circles). Additionally, we include 566 volcanic fields containing high spatial concentrations of edifices <20 km in diameter (yellow outlines). The outlines of major Venusian physiographic features are shown in grey for geographic context. The map is in Robinson projection, centered at 0°E.
Rebecca M. Hahn is the study’s lead author and senior graduate student in the Department of Earth and Planetary Sciences at Washington University in St. Louis.
With this, Rebecca has achieved well-deserved celebrity! It will be interesting to watch this woman’s career.
Paul K. Bryne is an Associate Professor of Earth and Planetary Science at Washington University in St. Louis, and a faculty fellow of the university’s McDonnell Center for the Space Sciences. His Twitter account claims he’s a Planetary Evangelist.
Jesuit Astronomer Roger Boscovich (1711-1787) studied telescope optics, cometary orbits, and promoted observations of the transits of Venus in 1761 and 1769.
At that time, 25% of all observatories in Europe were run by Jesuits; notably, the director of the Vienna Observatory, Maximilian Hell (1720-1792), observed the transit from Sweden by invitation of the Swedish king, at a time when Jesuits were otherwise banned from Sweden.
– From Jesuits and Astronomy
Jesuit Astronomer Maximilian Hell (1720-1792) became the director of the Vienna Observatory in 1756. He and his assistant János Sajnovics went to Vardø in the far north of Norway (then part of Denmark-Norway) to observe the 1769 transit of Venus. – Wikipedia
Br. Bob Macke will be working with samples from NASA’s OSIRIS-REx asteroid sample return mission; I wonder if any Jesuits will be working with the teams for the upcoming DAVINCI+ & VERITAS missions to Venus, or doing analysis on their datasets?
Data from Magellan
I’m always on the lookout for references to “Big Data,” and I think this one fits the bill:
The spacecraft returned 1,200 gigabits of data, far exceeding the 900 gigabits of data from all NASA planetary missions combined at the time.
Recall that the Magellan mission took place from 1989 – 1994, at the very dawn of the World Wide Web (www), and before the release of DVDs; CD-ROMs could hold between 553–900 MB of data. I exploded with laughter when I read the following line:
With the release of Magellan data on the compact disc read-only-memory (CD-ROM) a revolutionary new way of doing science has resulted. This technology provides a way to store, distribute and access large volumes of data.
Science.gov website about the Magellan mission
Yes, at the time it WAS revolutionary – but I have a dinky little 5 terabyte drive on my desk, and I know some astrophotographers that chew through drives that size like candy. How the times have changed!