Hecates Tholus
Encyclopedia
Hecates Tholus is a Martian
volcano
, notable for results from the European Space Agency
's Mars Express
mission which indicate a major eruption took place 350 million years ago. The eruption created a caldera
10 km in diameter. It has been suggested that glacial deposits later partly filled the caldera and an adjacent depression. Crater counts indicate this happened as recently as 5 to 20 million years ago. However climate models show that ice is not stable at Hecates Tholus today, pointing to climate change since the glaciers were active. It has been shown that the age of the glaciers correspond to a period of increased obliquity of Mars' rotational axis.
The volcano is at location 32.1°N 150.2°E, in Elysium Planitia
, and has a diameter of 183.0 km. It is the northernmost of the Elysium volcanoes; the others are Elysium Mons
and Albor Tholus
.
In planetary nomenclature
, a "tholus
" is a "small domical mountain or hill".
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
, notable for results from the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...
's Mars Express
Mars Express
Mars Express is a space exploration mission being conducted by the European Space Agency . The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. "Express" originally referred to the speed and efficiency with which the spacecraft was...
mission which indicate a major eruption took place 350 million years ago. The eruption created a caldera
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
10 km in diameter. It has been suggested that glacial deposits later partly filled the caldera and an adjacent depression. Crater counts indicate this happened as recently as 5 to 20 million years ago. However climate models show that ice is not stable at Hecates Tholus today, pointing to climate change since the glaciers were active. It has been shown that the age of the glaciers correspond to a period of increased obliquity of Mars' rotational axis.
The volcano is at location 32.1°N 150.2°E, in Elysium Planitia
Elysium Planitia
Elysium Planitia is the second largest volcanic region on Mars, after Tharsis Montes. It is centered at . It includes volcanoes, from north to south, Hecates Tholus, Elysium Mons and Albor Tholus. Another large volcano, Apollinaris Mons, lies south of the others. Besides having large volcanoes,...
, and has a diameter of 183.0 km. It is the northernmost of the Elysium volcanoes; the others are Elysium Mons
Elysium Mons
Elysium Mons is a volcano on Mars located in the Elysium Planitia, at , in the Martian eastern hemisphere. It stands about 13.9 km above the surrounding lava plains, and about 16 km above the Martian datum. Its diameter is about 240 km, with a summit caldera about 14 km across...
and Albor Tholus
Albor Tholus
Albor Tholus is an extinct volcano in the Elysium Planitia area on Mars. It lies south of the neighbouring volcanoes Elysium Mons and Hecates Tholus. Albor Tholus is 4.5 kilometres high and has a diameter of 160 km at its base. Its caldera has a diameter of 30 km and is 3 km deep, it...
.
In planetary nomenclature
Planetary nomenclature
Planetary nomenclature, like terrestrial nomenclature, is a system of uniquely identifying features on the surface of a planet or natural satellite so that the features can be easily located, described, and discussed. The task of assigning official names to features is taken up by the International...
, a "tholus
Tholus
In planetary geology, tholus is the term used to describe a small domical mountain or hill. The word is from the Greek θόλος, which means a circular building with a conical or vaulted roof. The Romans transliterated the word into the Latin tholus, which means cupola or dome...
" is a "small domical mountain or hill".
External links
- Google Mars - zoomable map centered on Hecates Tholus
- List of Martian tholi
- http://www.esa.int/SPECIALS/Mars_Express/SEMTXD2PGQD_0.html3-D view of Hecates Tholus from Mars ExpressMars ExpressMars Express is a space exploration mission being conducted by the European Space Agency . The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. "Express" originally referred to the speed and efficiency with which the spacecraft was...
]