Wiktionary
n. (context astronomy geology English) A small domical mountain or hill.
Wikipedia
In planetary nomenclature, a tholus (pl. tholi) is a small domical mountain or hill. The word is from the Greek θόλος, tholos (pl. tholoi), 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. In 1973, the International Astronomical Union (IAU) adopted tholus as one of a number of official descriptor terms for topographic features on Mars and other planets and satellites. One justification for using neutral Latin or Greek descriptors was that it allowed features to be named and described before their geology or geomorphology could be determined. For example, many tholi appear to be volcanic in origin, but the term does not imply a specific geologic origin. Currently (March 2015), the IAU recognizes 56 descriptor terms. (See Planetary nomenclature.) Tholi are present on Venus, Mars, asteroid 4 Vesta and on Jupiter's moon Io.
Quadrangle map-la.svg|Map of the Tharsis quadrangle showing major features, several of which are tholi. Tharsis contains many volcanoes, including Olympus Mons, the tallest known volcano in the solar system.
& Uranius tholi.jpg| 2001 Mars Odyssey THEMIS mosaic of Ceraunius Tholus (lower volcano) and Uranius Tholus (upper volcano). Ceraunius Tholus is about as high as Earth's Mount Everest.
Tholus.jpg|Western part of Jovis Tholus, as seen by THEMIS on Mars Odyssey spacecraft. Jovis Tholus is in the Tharsis quadrangle.
Usage examples of "tholus".
Drillings were made to a depth of one km under the north flank of Ceraunius Tholus, in locations where the ground was 10-50 microkelvins warmer than the flank median.
This suggests the rocks of Ceraunius Tholus were contaminated with Terran nanobacteria some 20 m-years ago, which is within the period when the lava tunnel on the north flank of the volcano was used as a streambed.
Elysium loomed beyond, a saddleback in shape, Elysium Mons and Hecates Tholus rearing at each end of a long spine range, five thousand meters higher than the bulge they punctuated: an awesome sight.
Out in the middle distance was the low bump of Tharsis Tholus, and to the left of it, just poking over the horizon, lay the purple cone of Ascraeus Mons, the northernmost of the great prince volcanoes, a full 1200 kilometers away.
Tall cliffs rise to the north, where the lava fields have been uplifted, and beyond them the domical summit of Kison Tholus itself is silhouetted against a salmon sky.
Jovis Tholus dome is five kilometers in diameter and only a tenth of it is allocated.
Not to mention that a single Astrographic article could bring in the equivalent in allocations of my entire Jovis Tholus University stipend for a year.
He continued north, rising over the plains of Cerberus, past the volcano Albor Tholus, a steep ash cone on the side of Elysium Mons.
They drove hard over the sastrugi and along ropy lava mounds that served as roads, north past the bulk of Tharsis Tholus, a volcano that was about the size of Mauna Loa, though under the rise of Ascraeus it looked like a cinder cone.
Drillings were made to a depth of 1 km under the north flank of Ceraunius Tholus, in locations where the ground was 10–50 microkelvins warmer than the flank median.
Drillings were made to a depth of one km under the north flank of Ceraunius Tholus, in locations where the ground was 10-50 microkelvins warmer than the flank median.
Surrounding Hellas were a number of ancient volcanoes, which just postdated the impact, including Australis Tholus to the southwest, Amphitrites Patera to the south, and Hadriaca Patera and Tyrrhena Patera to the northeast.
Jovis Tholus was a bigger volcano than Tharsis Tholus, bigger in fact than any volcano on Earth, but it was located on the high saddle between Ascraeus Mons and Olympus Mons, and both were visible on skysills to east and west, bulking like vast plateau continents, and making Jovis seem compact, friendly, comprehensible-a hill you could walk up if you wanted to.
Jovis Tholus was a bigger volcano than Tharsis Tholus, bigger in fact than any volcano on Earth, but it was located on the high saddle between Ascraeus Mons and Olympus Mons, and both were visible on skysills to east and west, bulking like vast plateau continents, and making Jovis seem compact, friendly, comprehensible—a hill you could walk up if you wanted to.
They drove by night and slept by day, in their old pattern, and in two nights made their way across Echus Chasma to Tharsis Tholus, a volcanic cone on the northern edge of the Tharsis bulge.