Crater Drains Into A Cavern on Mars

Crater on the flank of Pavonis Mons on Mars
Image Credit: NASA / JPL / University of Arizona

Earlier this year, NASA’s Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) captured an image of a crater with a block dot in the center on the slopes of the Pavonis Mons volcano. Mission managers decided to have another look, this time with the High Resolution Imaging Science Experiment (HiRISE).

The black dot turned out to be a skylight 35 meters across leading into a cavern below. The cavern is likely a lava tube located beneath the surface of the volcano. Based on the shadow, the floor is about 20 meters below the skylight.

Speculation centers on the formation of the crater. It could be a sink hole formed from the loose dust on the volcano flowing into the cavern when the roof collapsed. In this closeup, one can see how the walls of the crater have slumped and material has flowed into the cavern below.

The hole might also be from a small meteorite that punched a hole through the lava tube. There does not seem to be much (if any) rim from a meteorite strike and the crater it would have created. Then, there is speculation that the underground cavern is a former ice deposit that has been exposed and sublimated into the Martian atmosphere.

Later this year, the HiRISE mission plans another image of the crater, creating a stereo picture that may help resolve the mystery.

NASA – ISS Science Success – Part III

Part I, Part II, Part III
International Space Station. Credit: NASA Image
In Part I, we looked at “Technology Development for Exploration” and “Physical Sciences in Microgravity” aboard the International Space Station from NASA’s report on “International Space Station Science Research Accomplishments During the Assembly Years: An Analysis of Results from 2000-2008”. In Part II, we reviewed “Biological Sciences in Microgravity” and the “Human Research Program”.

The major areas of research from the report include:

  • Technology Development for Exploration
  • Physical Sciences in Microgravity
  • Biological Sciences in Microgravity
  • Human Research Program
  • Observing the Earth and Educational Activities
  • Science from International Space Station Observations

Here in Part III, we will highlight the final two sections: “Observing the Earth and Educational Activities” and “Science from International Space Station Observations”.

Observing the Earth and Educational Activities
Amateur Radio on the International Space Station. From p 161:

Ever since the Amateur Radio on the International Space Station (ARISS) hardware was first launched aboard Space Shuttle Atlantis on STS-106 and transferred to ISS, it has been regularly used education outreach. With the help of Amateur Radio Clubs and HAM radio operators, astronauts and cosmonauts aboard the ISS have been speaking directly with large groups of the general public, showing teachers, students, parents, and communities how amateur radio energizes students about science, technology, and learning. The overall goal of ARISS is to get students interested in mathematics and science by allowing them to talk directly with the crews who are living and working aboard the ISS.

You can follow Amateur Radio here.

Credit: NASA. Astronaut Sunita L. Williams, Expeditions 14 and 15 flight engineer, talks with students at the International School of Brussels in Belgium during an ARISS session in the Zvezda service module.

Crew Earth Observations

Although crew observations of the Earth sometimes lack the precision and scientific value of dedicated spacecraft orbiting the Earth, crew photographs and observations continue to fascinate the public and benefit science. The ability of crew aboard the ISS to react immediately to targets of opportunity means that events such as the 2004 tsunami in Indonesia, the hurricanes Katrina and Wilma and the Mt Etna eruptions can be documented in real time, directed by scientists on the ground.

Through December 2007, more than 300,000 images of the Earth have been taken. Scientists and the public around the world have access to CEO images that were captured by astronauts on ISS through the Gateway to Astronaut Photography of Earth Web site (

As an example of published research involving the coordination of ISS images with other spacecraft platforms, the report states:

Extracting clear water depths from a variety of sources allows the examination and mapping of shallow water from global to local scales. Scientists from the National Oceanic and Atmospheric Administration (NOAA) used four sources of data to map shallow water bathymetry near U.S. coral reef areas. These included the sea-viewing wide field-of-view sensor (SeaWiFS) on board the OrbView 2 Satellite (SeaWiFS allows global mapping within 1-kilometer pixels), the IKONOS satellite (global mapping within 4 meters), the Landsat Satellite (global mapping within 30 meter pixels), and handheld photography by the ISS crew (CEO local mapping within 6 meters). A new technique was applied to the blue and green bands from astronaut photography, allowing construction of a bathymetry map for Pearl and Hermes reef with accuracies similar to that obtained from IKONOS (Stumpf et al. 2003).

Cleveland Volcano, Alaska
Image Credit: NASA – iss013e24184
As an example of initial discovery capability aboard the ISS, “flight engineer Jeff Williams was the first to report the volcanic eruption of Cleveland Volcano in Alaska on May 23, 2006. This image shows the eruption cloud moving west-southwest from the volcano summit. The Alaska Volcano Observatory was contacted and was able to monitor the volcanic activity. This image was captured using the Kodak 760c camera equipped with a 800mm lens”.
The tracking system for images like these were pioneered by ISS Expedition 6 science officer Don Pettit using a homemade tracking system to track the ground as it moves relative to station. Pettit runs a drill while looking through EarthKAM mounted on the nadir window in the U.S. Destiny laboratory. The device is called a “barn door tracker.” The drill turns the screw, which moves the camera and its spotting scope. Don Pettit
Image Credit: NASA – ISS006E44305

Additional examples of ISS observations and experiments involving student education work include:

  • “The Commercial Generic Bioprocessing Apparatus Science Insert-01 (CSI-01) was the first in a series of experiments for the K–12 education program from BioServe Space Technologies at the University of Colorado-Boulder. This C. elegans experiment involved over 5,000 middle school students (grades 6 – 9) who were located in Texas, Arizona, Michigan, Florida, California, New Mexico, Wisconsin, and Montana, as well as several thousand students from Malaysia. The C. elegans experiment was part of the Orion’s Quest education program (; video of the worms are available on the Web site”. (p 169).
  • “CSI-02 is an educational payload that is designed to interest middle school students in STEM by providing the opportunity for these students to participate in near-real-time research conducted on board the ISS. Each experiment was designed to be easily reproducible in the classroom, providing hands-on experience to the students. The seed germination and plant development experiment provided the opportunity for younger students to begin to understand how gravity affects germination and plant development. Small seeds were germinated on orbit in BioServe-developed hardware. The students examined root and stem growth and plant development over a period ranging from a few weeks to 2 months. Classroom kits were available from BioServe for teachers”. (p 171)
  • “The objective of the Education Payload Operations (EPO) investigation was to use toys, tools, and other common items in the microgravity environment of ISS to create educational video and multimedia products that inspire the next generation of engineers, mathematicians, physicists, and other scientists. To date, over 500 videos, DVDs, and video clips have been produced and distributed to science teachers and schools throughout the United States”. (p 173)
  • During the Education-Space-Exposed Experiment Development for Students (SEEDS) experiment, eight pouches of soybean and corn seeds flew on ISS and germinated under either dark or lighted conditions. (p 179)

Science from International Space Station Observations

Finally, some additional interesting studies:

  • Clinical Nutrition Assessment. Publications from this robust project:
    • Hall PS. Past and Current Practice in Space Nutrition, in P Cavanagh and AJ Rice (eds.), Bone Loss During Spaceflight: Etiology, Countermeasures, and Implications for Bone Health on Earth. Cleveland Clinic Press, Cleveland, Ohio (2007), pp. 125–132.
    • Smith S, Zwart SR, Block G, Rice BL, Davis-Street JE. The nutritional status of astronauts is altered after long-term space flight aboard the International Space Station. Journal of Nutrition. 2005; 135(3):437–443.
    • Smith S, Zwart, SR, Block G, Rice BL, Davis-Street JE. The Nutritional Status of Astronauts is Altered After Long-Term Space Flight Aboard the International Space Station, in P Cavanagh and AJ Rice (eds.), Bone Loss During Spaceflight: Etiology, Countermeasures, and Implications for Bone Health on Earth. Cleveland Clinic Press, Cleveland, Ohio (2007), pp. 133–147.
    • 79BSmith SM, Zwart SR. Nutrition issues for space exploration. Acta Astronautica. 2008; 63:609–613.
  • The plasma interaction model (PIM) collected measurements of the ionospheric plasma around the ISS using the floating potential probe (FPP), which was mounted outside on an ISS truss until it was jettisoned in late 2005. (p 193)
  • Soldering in Reduced Gravity Experiment (SoRGE). (p. 196)
  • Exploration Lessons Learned from the Operation of ISS. This is left to the reader, as a summary of “non-eigenaxis attitude trajectory” is not possible within the space available. Read pp 197-198 and referenced publications.
  • Medical Monitoring of ISS Crewmembers, Exploration Lessons Learned from the Operation of ISS. Several papers have been published reporting the engineering and operational ramifications resulting from the data that were collected from the ISS space environment. The results fall into a couple of broad categories (p. 199):
    • Radiation environmental effects on ISS
    • External contamination of ISS
    • Other environmental assessments, including thruster plume contamination and condensate venting

The report is a great read, full of interesting, odd and bizarre research projects. A lot of the work depends on the ISS. And the expansion to a full six crew members makes future research a lot more feasible. Now that we have it, lets see what the International Space Station can do for human space flight research.

Part I, Part II, Part III