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California seventh-graders spot possible lava tube skylight on Mars 24 June 2010

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There’s no scale with the NASA/JPL image of the Martian surface on the left, but the black dot inside the red square is a large hole in the surface of Mars, about 190 x 160 metres in size and about 115 metres deep. It is situated on the slopes of Pavonis Mons, a volcano in the equatorial region of Mars, and may well be a skylight – an opening in the roof of a lava tube created during past volcanic activity (more on Martian lava tube caves here). It was spotted by a group of seventh-grade science students at Evergreen Middle School, Cottonwood, California, who have been taking part in the Mars Student Imaging Project run by NASA and Arizona State University. ‘The Mars Student Imaging Program is certainly one of the greatest educational programs ever developed’, says the students’ science teacher, Dennis Mitchell. ‘It gives the students a good understanding of the way research is conducted and how that research can be important for the scientific community. This has been a wonderful experience’.

Image credit: NASA/JPL-Caltech/ASU.

News
7th-graders discover mysterious cave on Mars – MSNBC, 21 June 2010
Mars cave opening found by 7th graders – CBS News, 22 June 2010
Teen project one-ups NASA, finds hole in Mars cave – AFP, 23 June 2010

The Volcanism Blog

Volcanism and the tides of life 18 June 2009

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If the tidal forces of strong gravitational fields are constantly twisting a planet’s guts like a strong man squeezing the pips out of a lemon and generating continual paroxysms of violent volcanism then it’s probably not an ideal environment for life, says a confused article from ScienceNOW (the ‘caps lock stuck’ people).

The foremost example of ‘tidal’ volcanism in the Solar System is Jupiter’s fascinating moon Io. The elliptical orbit which Io follows around Jupiter – the product of a complex interaction with its neighbouring satellites Europa and Ganymede – subjects it to varying strengths of gravitational pull, producing a constant flexing of the surface. It is this which drives Io’s constant and violent volcanic activity. However, New Scientist reports that a new French study of Io’s orbital motion reveals that Io is moving closer to Jupiter, while Europa and Ganymede are moving further away, so this situation won’t go on for ever. The end may come very quickly, they say: in 100 million years or less.

News
Recipe for life: water and a little lavaScienceNOW, 15 June 2009
Solar system’s most volcanic body to go dormantNew Scientist, 18 June 2009

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Olympus Mons and our ‘life on Mars’ obsession 5 March 2009

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Over the past 24 hours quite a few stories have appeared in the media about a paper in the journal Geology on Olympus Mons, the giant Martian volcano. Can you spot what they have in common?

Here’s a hint: the ‘big question’ in the last headline is ‘whether the Red Planet had – or still supports – life’. Life on Mars is clearly what the Geology paper is all about.

It isn’t, of course. The paper concerned, Patrick K. McGovern & Julia K. Morgan, ‘Volcanic spreading and lateral variations in the structure of Olympus Mons, Mars’ (discussed here at The Volcanism Blog three weeks ago) is, as its title indicates, about the geology of Olympus Mons – specifically, why the volcano is the shape it is. The ‘big question’ of life gets a mention in the final paragraph.

An implication of the paper’s thesis – that Olympus Mons is underlain by clay sediments – is that there might be a reservoir of water beneath the volcano in which conditions suitable for thermophilic life might have been maintained. They only mention it in passing.

I suppose it’s understandable that Martian life is always going to have a higher media profile than Martian sedimentary geology. Is that healthy for science, though? And is there a danger that our Martian discoveries are always going to be viewed through the distorting lens of our ‘life on Mars’ obsession?

  • Patrick K. McGovern & Julia K. Morgan, ‘Volcanic spreading and lateral variations in the structure of Olympus Mons, Mars’, Geology, vol. 37, no. 2 (February 2009), pp. 139-142. [Link to abstract only]

The Volcanism Blog

Olympus Mons, lopsided giant 11 February 2009

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Mosaic of Olympus Mons (NASA/NSSDC).

Olympus Mons, the largest mountain and the largest volcano we know of in the Solar System, is a huge shield volcano on Mars. It rises 23km above the Martian plain, is approximately 600km in diameter, and is lopsided, like a vast unsuccessful cake. The gently-sloping north-west flank of the volcano extends much further from the central caldera complex than does the steeply-sloping south-eastern flank; these flanks are also upwardly concave, showing an overall increase in the steepness of slope towards the centre, and are divided from the surrounding terrain by steep scarps, features not found in other sectors. A new paper on Olympus Mons in the February 2009 issue of Geology looks at the possible reasons for what it calls these ‘substantial asymmetries in its structure’. From the abstract:

The NW-SE asymmetries are aligned with the regional slope from the Tharsis rise, but an understanding of the underlying causes has remained elusive. We use particle dynamics models of growing, spreading volcanoes to demonstrate that these flank structures could reflect the properties of the basement materials underlying Olympus Mons. We find that basal slopes alone are insufficient to produce the observed concave-upward slopes and asymmetries in flank extent and deformation style that are observed at Olympus Mons; instead, lateral variations in basal friction are required. These variations are most likely related to the presence of sediments, transported and preferentially accumulated downslope from the Tharsis rise. Such sediments likely correspond to ancient phyllosilicates (clays) recently discovered by the Mars Express mission.

Thus the north-west flank of the edifice spreads more easily across the thickened sediments downhill from the Tharsis rise, while the south-east flank encounters the high-friction zone of the elevated pre-sediment basement which inhibits its spread. Result: a lopsided volcano. The sediments beneath forming the low-friction basal zone beneath Olympus Mons would need to be good at retaining water, making clays the obvious candidates, and the authors note that the spectral signatures of clay materials have been detected by the Mars Express OMEGA imaging spectrometer.

In the last, four-sentence, paragraph of the paper the authors suggest that ‘[these] results have implications for extant life on Mars’. The erupted lavas of Olympus Mons could have trapped a water reservoir in the sediments beneath: ‘This deep reservoir, warmed by geothermal gradients and magmatic heat and protected from adverse surface conditions, would be a favored environment for the development and maintenance of thermophilic organisms’. Hence the headline at Australia’s ABC Science today: ‘Martian volcano could shelter life’.

  • Patrick K. McGovern & Julia K. Morgan, ‘Volcanic spreading and lateral variations in the structure of Olympus Mons, Mars’, Geology, vol. 37, no. 2 (February 2009), pp. 139-142. [Link to abstract only]

Image: mosaic of Olympus Mons created with the medium-resolution black and white MDIM combined with a low resolution color image mosaic acquired on the 735 orbit of Viking 1 on 22 June 1978. Image Processing by Jody Swann/Tammy Becker/Alfred McEwen, using the PICS (Planetary Image Cartography System) image processing system developed at the U.S. Geological Survey in Flagstaff, Arizona (NASA/NSSDC image).

News
Volcanic spreading and lateral variations in structure of Olympus Mons, Mars – ScienceDaily, 3 February 2009
Martian volcano could shelter life – ABC Science, 11 February 2009

Information
ESA – Mars Express – home page for the ESA Mars Express mission
Unravelling part of Olympus Mons’ geologic history – HiRISE High Resolution Imaging Science Experiment (University of Arizona)
Volcanic Geology of Mars – from Albert T. Hsui, University of Illinois (Urbana-Champaign)
Highest and lowest points on Mars – Geology.com (on Olympus Mons and the Hellas Impact Crater)
Olympus Mons – Mike Dunford at The Questionable Authority shows just how big Olympus Mons is

The Volcanism Blog

Nicaraguan volcanoes and life on Mars 29 September 2008

Posted by admin in Cerro Negro, current research, Mars, Nicaragua, solar system.
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‘Although volcanoes on Mars today are dormant or extinct’, says the summary of this Astrobiology Magazine story, ‘in the distant past the Red Planet was literally a hotbed of volcanic activity’. Yes, literally a hotbed. ‘Cerro Negro, an active volcano in Nicaragua, offers clues to what the martian era of fire and brimstone may have been like – and what types of organisms could have lived in that superheated world’.

It seems Cerro Negro, the youngest volcano in Central America (born April 1850), offers Martian-type basalts that can provide terrestrial analogs to possible conditions in and around the volcanoes of Mars back in the ‘martian era of fire and brimstone’. To find out more, take a look at ‘Nicaraguan volcano provides insight into early Mars’ at Astrobio.net.

The Volcanism Blog

Extraterrestrial volcanism on Io at Geology News 23 September 2008

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Io's Tvashtar volcano erupting (NASA image)

There is a superb post about Jupiter’s highly volcanically active moon Io over at Geology News. This kind of richly-illustrated, detailed article really is the geoblogosphere at its best, and is one of Dave Schumaker’s two contributions to what promises to be a first-rate Accretionary Wedge on ‘Geology in Space’. Highly recommended – go and take a look.

N.B. Geology News has passed the 400 posts milestone – congratulations!

Picture: NASA New Horizons image of Io’s Tvashtar volcano erupting (NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute). Source page and more information here.

The Volcanism Blog

Io: ‘bursting with volcanoes’ 29 May 2008

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A new article in Geotimes paints a vivid picture of Jupiter’s moon Io, which is squeezed and stretched into a frenzy of volcanism by the tidal influence of Jupiter’s gravitational pull and that of its nearby moons Europa and Ganymede:

Io, a sulfurous rock about the size of Earth’s moon, is bursting with volcanoes. With more than 400 active vents spewing red-hot lava, the moon is by far the most geologically active body in our solar system. Some of Io’s most spectacular eruptions eject plumes of debris nearly 500 kilometers into outer space. Io’s surface churns so vigorously that the landscape is devoid of the impact craters that characterize our moon or planets such as Mars. Instead, Io’s tumultuous surface is covered with vast calderas the size of Texas, huge sulfurous lakes and extensive lava flows.

For more, see ‘Io: a different kind of hell’ by Mary Caperton Morton, in the May 2008 Geotimes.

The Volcanism Blog

Active volcanoes on Venus? 12 April 2008

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The European Space Agency’s Venus Express probe has found highly variable quantities of sulphur dioxide in the atmosphere of Venus, prompting the question: is this evidence for active volcanoes on Venus, or the result of some hitherto unknown process in the planet’s upper atmosphere?

Some scientists have argued that the large proportion of sulphur dioxide found by previous space missions at Venus is the ‘smoking gun’ of recent volcanic eruptions. However, others maintain that the eruptions could have happened around 10 million years ago and that the sulphur dioxide remains in the atmosphere because it takes such a long time to react with the surface rocks.

New observations from Venus Express showing rapid variations of sulphur dioxide in the upper atmosphere have revived this debate.

The variations in sulphur dioxide levels in the upper atmosphere were found by the SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) instrument, while VIRTIS (Visible and Infrared Thermal Imaging Spectrometer), with its ability to see through atmospheric cloud, will be used to analyze the planet’s surface for signs of active volcanism.

Search for active volcanoes on Venus in high gear – ScienceDaily, 8 April 2008
ESA Science & Technology: Venus Express – ESA home page for the Venus Express mission

The Volcanism Blog

Mercury’s volcanic past revealed 31 January 2008

Posted by admin in current research, Mercury, solar system, volcanology.
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Data from the first flyby of Mercury by a spacecraft in more than three decades has revealed evidence of the planet’s volcanic past. ‘”There’s very little doubt that there have been widespread volcanoes on Mercury’s surface,” said Louise Prockter, a mission scientist from Johns Hopkins University in Maryland. This volcanism, she said, was one of Mercury’s biggest surprises’ (National Geographic News). There is evidence of surface features filled with lava flows, according to the mission bulletin for 30 January 2008, notably the 1550-kilometre wide Caloris basin:

The plains inside the Caloris basin are distinctive and have a higher reflectance —albedo—than the exterior plains, the opposite characteristics from many lunar impact basins such as the Imbrium basin on the Moon, yet another new mystery for Mercury. This finding could be the result of several processes—when the basin was formed by a large impact, deeper material may have been excavated that contributed to impact melt now preserved on the basin floor; alternatively, the basin interior may have been volcanically resurfaced by magma produced deep in Mercury’s crust or mantle subsequent to the impact. The science team is eagerly exploring the possibilities.

An enigmatic feature informally dubbed ‘the spider’ may also be evidence of volcanism. The feature consists of a central elevated 40-kilometre wide crater surrounded by over 100 radiating troughs, although scientists report that the relationship between the crater and the troughs is not clear:

‘The Spider has a crater near its centre, but whether that crater is related to the original formation or came later is not clear at this time,’ said James Head, science team co-investigator at Brown University in Providence.

Robert Strom, professor emeritus at the University of Arizona in Tucson [who worked on the Mariner 10 mission to Mercury and Venus in the 1970s], said he thought The Spider might eventually be tied to the history of volcanism on the planet.

NASA’s probe, Messenger (MErcury Surface, Space ENvironment, GEochemistry, and Ranging – a somewhat contrived acronym, even by US standards), made its first flyby of Mercury on 14 January 2008. Two more are planned, before Messenger settles into orbit around the planet in March 2011.

Information
MESSENGER: Unlocking the Secrets of Mercury – NASA Messenger mission site
MESSENGER – Johns Hopkins University Messenger mission site
Mercury Fact Sheet – facts and data from NASA
Solar System Exploration: Planets: Mercury – much more information from NASA

News
Bizarre spider scar found on Mercury’s surface – New Scientist Space, 30 January 2008
Mercury is shrinking, volcanic – Associated Press, 30 January 2008
Weird ‘Spider’, volcanism discovered on Mercury – National Geographic News, 30 January 2008
Mercury’s volcanic past revealed – BBC News, 30 January 2008
Pictures reveal Mercury’s tumultuous past – New York Times, 31 January 2008

The Volcanism Blog

Early Martian oceans: the volcanic connection 21 December 2007

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A study to be published in Science magazine for 21 December 2007 argues that volcanically-produced sulphur dioxide and hydrogen sulphide may have kept Mars warm enough to sustain liquid water oceans during the early history of the red planet, around 4 billion years ago.

The paper, ‘A sulfur dioxide climate feedback on early Mars’, by Itay Halevy (Harvard University), Maria T. Zuber (MIT) and Daniel P. Schrag (Harvard University), is in Science, vol. 318, no. 5858, pp. 1903-1907. Abstract:

Ancient Mars had liquid water on its surface and a CO2-rich atmosphere. Despite the implication that massive carbonate deposits should have formed, these have not been detected. On the basis of fundamental chemical and physical principles, we propose that climatic conditions enabling the existence of liquid water were maintained by appreciable atmospheric concentrations of volcanically degassed SO2 and H2S. The geochemistry resulting from equilibration of this atmosphere with the hydrological cycle is shown to inhibit the formation of carbonates. We propose an early martian climate feedback involving SO2, much like that maintained by CO2 on Earth.

Related articles
Fire and brimstone helped form Mars Oceans – LiveScience (20 December 2007)
Sulfur dioxide kept ancient Mars ocean flowing – National Geographic News (20 December 2007)
Sulfur dioxide may have helped maintain a warm early Mars – ScienceDaily (20 December 2007)
Greenhouse clue to water on Mars – BBC News (20 December 2007)

The Volcanism Blog