I know this might not be a very popular matter, is not even funny, but the thing is that it never seazes to amaze me how little we know, how much there is to understand. This is a little research work comparing volcanic traces on different planets and other stars of the solar system with those found here on Earth. The resemblance and similarities help explain and understand a bit more of the rock where we lay our feet on. If you are not interested on this, at least photographs are cool!
1. Olympus Mons, Mars-Hawaii Comparison
The martian volcano Olympus Mons (18°N, 133°W) is one of the largest volcanos in the solar system, measuring over 600 kilometers across and rising more than 27 kilometers above the surrounding plain. In this view, Olympus Mons is compared to the Hawaiian Islands, and demonstrates the value of comparative planetary volcanology. Notice that the Island of Oahu would easily fit inside the summit caldera of the martian volcano. Volcanologists on Earth have a good understanding of Hawaiian volcanism, but the eruptive style and duration of planetary examples such as Olympus Mons remain poorly understood.
2. The 1859 Mauna Loa Lava Flow, Hawaii
This view of the west coast of the Big Island of Hawaii, taken from the space shuttle, shows the entire 50-kilometer length of the 1859 lava flow from Mauna Loa volcano. This is one of the largest lava flows in the world that has been erupted in historic times. The eruption occurred at the 11,000-foot elevation level (close to the summit at right), lasted about 200 days, and produced a pahoehoe and a'a lava flow that traveled all the way to the coast (left). Although one of the largest young lava flows on Earth, the Mauna Loa flow is small compared to most of the flows seen on Mars (#6), Io (#7), and Venus (#8).
3. A'a Lava Flow, Hawaii
This view of the west coast of the Big Island of Hawaii, taken from the space shuttle, shows the entire 50-kilometer length of the 1859 lava flow from Mauna Loa volcano. This is one of the largest lava flows in the world that has been erupted in historic times. The eruption occurred at the 11,000-foot elevation level (close to the summit at right), lasted about 200 days, and produced a pahoehoe and a’a lava flow that traveled all the way to the coast (left). Although one of the largest young lava flows on Earth, the Mauna Loa flow is small compared to most of the flows seen on Mars (#6), Io (#7), and Venus (#8).
4. Pahoehoe Lava Flow, Hawaii
As a pahoehoe flow spreads out across the ground, the flow surface cools and the majority of lava transport takes place through a series of tubes. In this view the leading edge of the flow field is advancing via a series of break-outs of lava from such a tube system. As can be seen from the scale bar in the image (which is marked in 5-centimeter increments), pahoehoe flows are much thinner than a’a flows, sometimes being only 30-50 centimeters thick.
5. Pahoehoe Lava Flow, Hawaii
The classic “ropy” texture of a pahoehoe lava flow is shown here. Scale bar is marked in 5-centimeter increments.
6. Lava Flow Field, Elysium Planitia, Mars
There are several fine examples of compound martian lava flow fields. This one is just west of the volcano Hecates Tholus, within Elysium Planitia (33°N, 214°W). Several lava flows more than 100 kilometers in length can be found (the direction of flow in this image is from the bottom to the top of the slide). The insert compares these martian flows to the recent activity at Pu’u O’o on the East Rift Zone of Kilauea, Hawaii. Shown in red are the Pu’u O’o lavas erupted between 1983 and 1986, and in blue are the flows erupted from the Kupaianaha lava pond between 1986 and 1991 (slide #19). The distance between the Kupaianaha vent and the coast is approximately 10 kilometers.
7. Ra Patera, Io
Long lava flows exist on other planetary bodies including Io, a moon of Jupiter. At top right we see a sequence of flows over 150 kilometers in length that have been erupted from Ra Patera (8.4°S, 325.3°W). The state of Hawaii, which is approximately 130 × 150 kilometers in size, has been superimposed in red on this image for a scale comparison.
8. Sapas Mons, Venus
Numerous large overlapping lava flows are shown in this Magellan radar image of Sapas Mons on Venus (8°N, 188°E). Sapas Mons is approximately 400 kilometers across and 1.5 kilometers high. Smooth (pahoehoe) lava flows typically appear dark in radar images, while rougher (a'a) flows will have a higher radar backscatter and so will appear bright in Magellan data. From this scene, we can infer that long lava flows on Venus are comparatively rough at the radar wavelength of 12 centimeters. The Big Island of Hawaii, which is approximately 130 × 150 kilometers in size, has been superimposed in blue for scale comparison.
9. Pu'u O'o Lava Channel, Hawaii
During many of the eruptions of Pu’u O’o Volcano, Hawaii, pahoehoe lava flows became channelized so that the margins (called “levees”) became more solid and the lava was moving most rapidly in a central channel. These central channels can also be found within certain lunar and martian lava flows and are thought to be an indicator of high discharge rates (more than 10 million kilograms per second). The central channel shown here is approximately 4 meters wide.
10. Thurston Lava Tube, Hawaii
In Hawaii, many lava flows form tubes that may extend for several kilometers. This is an efficient way for the lava to travel comparatively large distances without significant cooling. Thurston Lava Tube, located close to the summit of Kilauea Caldera, is a fine example of this type of landform. Here the tube is approximately 3 meters in diameter. Note two lava benches on the wall on the left.