Geology News - Earth Science Current Events

The Mars Global Surveyor has transmitted photos of sand dunes from the Martian North Polar Area which is currently approaching the spring season. These dunes appear white in the image because they are covered by a seasonal layer of carbon dioxide frost. As the northern hemisphere of Mars warms the frost sublimes away exposing the dark sand below.


Image by NASA-JPL-Malin Space Science Systems

Labels: Planets

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The Hubble Space Telescope has refined the size of Xena, the tenth planet. Ground based estimates were about 25% too high. Hubble's new estimate of Xena's diameter is about 1490 miles +/- 60 miles. This makes it approximately the same size as Pluto, which is 1422 miles.

"Hubble is the only telescope capable of getting a clean visible-light measurement of the actual diameter of Xena," said Mike Brown, planetary scientist at the California Institute of Technology in Pasadena, California and leader of the team that discovered the tenth planet.

Xena's high reflectivity was part of the reason for the inaccurate ground-based size estimate. Since it is smaller than previously thought, it must be one of the most reflective objects in the solar system. The only object more reflective is Enceladus, a geologically active moon of Saturn whose surface is continuously recoated with highly reflective ice by active geysers.

Xena's bright reflectivity is possibly due to fresh methane frost on its surface. This methane could be discharged from the planet's interior to freeze on the surface.


Image by NASA, ESA, and A. Feild (STScI)Read more about estimating the size of the tenth planet.

Labels: Planets

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These color maps of Jupiter were produced using images created by NASA's Cassini spacecraft during its 2000 flyby - on the way to Saturn. They are the most detailed color maps of Jupiter ever produced.


Image by NASA - Jupiter Northern Hemisphere

Image by NASA - Jupiter Southern Hemisphere (High Resolution)
NASA's interpretation of these images...

"The maps show a variety of cloud features, including parallel reddish-brown and white bands, the Great Red Spot, multi-lobed chaotic regions, white ovals and many small vortices. Many clouds appear in streaks and waves due to continual stretching and folding by Jupiter's winds and turbulence. The bluish-gray features along the north edge of the central bright band are equatorial "hot spots," meteorological systems such as the one entered by NASA's Galileo probe. Small bright spots within the orange band north of the equator are lightning-bearing thunderstorms. The polar regions shown here are less clearly visible because Cassini viewed them at an angle and through thicker atmospheric haze."

Labels: Planets

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The Mars Reconnaissance Orbiter has returned its first test images of Mars clearly showing craters, channels, plains, dunes and many other features. These images were shot from over 1547 miles above the Martian surface and have a resolution of about eight meters per pixel - comparable to some of the best images previously collected. Future images will be collected from a lower altitude and have much better detail.




Images by NASA - View top image at high resolution (3 MB)

The top scene covers an area about 49.8 kilometers (30.9 miles) wide and 23.6 kilometers (11.7 miles) high from Mars' mid-latitude southern highlands. A very large, older crater can be seen in the central part of the image and smaller, much younger craters can be seen at many locations. Multiple channels can be seen to the west and south east of the large older crater. Smooth areas, covered with loose debris can be seen throughout the scene. In several areas this loose debris has been formed into dunes by the Martian winds. The channels suggest that water has played a role in shaping the Martian landscape.

See more details at the Mars Reconnaissance Orbiter Website.

Labels: Planets

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Go to the NASA website, browse their Solar System Collection and vote for your favorite images. Results are tallied right now on their Solar System Exploration page. In the top ten at this moment are... Cassini Launch, Comet Neat, Mars Over Moon, Full-Disk Neptune, Jupiter Eye to Io, 10,000 Galaxies, Tvashtar Catena, Cassini's Farewell, Planet Mercury, Antarctic Meteorite Sites. Some very nice images.

Screen Shot from NASAVote for your favorite Solar System Image at NASA.gov.

Labels: Planets

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NASA scientists have created a map of Mars crustal magnetism using data collected by the Mars Global Surveyor spacecraft. This high resolution magnetic field map covers the entire surface of Mars and displays "magnetic stripes" similar to what are found in the Earth's ocean basins. These stripes and other features are interpreted by NASA scientists as being evidence that Mars has undergone plate tectonics.

Image by NASARead more about Mars Geology and Plate Tectonics at the NASA website.

Labels: Planets, Plate-Tectonics

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Xena, nickname of the recently discovered tenth planet, is now believed to have a moon, which has been nicknamed Gabrielle. A group of astronomers, lead by Michael Brown of the California Insititue of Technology noticed a small object accompanying the Tenth Planet. Since this object moves with the planet and is not stationary it is believed to be a moon and not a star beyond the planet.
Read more about the Tenth Planet's Moon at AOL News and find interesting facts about the tenth planet at http://www.tenthplanet.info

Labels: Planets

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Astronomers at the Palomar Observatory have discovered what they believe is the tenth planet. Located in the Kuiper Belt, nearly 100 astronomical units from the sun, it is the furthest known object in our solar system and has a size larger than Pluto.

Read more about the Tenth Planet at the California Institute of Technology website.

Labels: Planets

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Astronomy Picture of the Day has posted an interactive topographic map of Mars. There you can explore volcanoes of the Tharsis province (much larger than any mountains on Earth), Valles Marineris (a canyon much longer and deeper than Earth's Grand Canyon) and Hellas Planitia (a basin over 2000 kilometers wide that was likely created by a collision with an asteroid).


Images by NASAVisit the NASA website to see the Mars Topographic Map

Labels: Maps, Planets

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