The Cassini probe, in orbit around Saturn, has captured a new radar image showing a long river on Titan, Saturn’s largest moon.
From the European Space Agency:
“The international Cassini mission has spotted what appears to be a miniature extraterrestrial version of the Nile River: a river valley on Saturn’s moon Titan that stretches more than 400 km from its ‘headwaters’ to a large sea.
It is the first time images have revealed a river system this vast and in such high resolution anywhere beyond Earth.
Scientists deduce that the river is filled with liquid because it appears dark along its entire extent in the high-resolution radar image, indicating a smooth surface.
Titan is the only other world we know of that has stable liquid on its surface. While Earth’s hydrologic cycle relies on water, Titan’s equivalent cycle involves hydrocarbons such as ethane and methane.
Images from Cassini’s visible-light cameras in late 2010 revealed regions that darkened after recent rainfall.”
HT: Clastic Detritus
Grace and Peace
Mitt Romney’s Environmental Platform — Ummm, Mitt Romney doesn’t seem to have an environmental platform. The menu at mittromney.com doesn’t have “Environment” as an option.
There isn’t anything substantial about the environment that I could find on the site. I am a conservative, and will vote for Romney in November. But why can’t we have a conservative presidential candidate who would actually be interested in conserving?
Richard Dawkins’ sloppy scholarship — Jay Wile does a good job of exposing militant atheist Richard Dawkins’ poor use of quotations. “This situation is very interesting, because creationists are often accused of quote mining, but here is a clear case where one of the greatest evolutionary evangelists of our time is doing it.”
The “Planet Debate” renewed? — A few years back, Pluto was demoted, so now we have only eight planets in the solar system. The debate is certain to be renewed at same point, not only about Pluto, but also about a couple of asteroids. The NASA article NASA Dawn Spacecraft Reveals Secrets of Large Asteroid refers a number of times to the planet-like qualities of the asteroid Vesta, such as having an interior differentiated into layers, including an iron core.
N.T. Wright sings about Genesis — sung to the tune of “Yesterday” by the Beatles. Watch it at the Internet Monk. Wright isn’t the world’s greatest musician, but he inserts a lot of theological issues into a few verses.
Why they had to fall, I don’t know, it doesn’t say
They did something wrong, and we’ve longed for God’s new day-ay-ay-ay
Grace and Peace
From today’s Astronomy Picture of the Day: NASA Dawn’s Virtual Flight Over Asteroid Vesta
Grace and Peace
Is Ansel Adams still alive and in orbit around Mars?
From Astronomy Picture of the Day, April 22, 2012: Flowing Barchan Sand Dunes on Mars.
Barchans are crescent-shaped sand dunes, with two horns that point downwind. They form in areas of limited sand supply; on this image you can see that the dunes occupy less than ten percent of the plain. And they are very photogenic.
Grace and Peace
The science team that oversees the imaging system on board NASA’s Lunar Reconnaissance Orbiter (LRO) has released the highest resolution near-global topographic map of the moon ever created.
This new topographic map, from Arizona State University in Tempe, shows the surface shape and features over nearly the entire moon with a pixel scale close to 100 meters (328 feet). A single measure of elevation (one pixel) is about the size of two football fields placed side-by-side.
Although the moon is our closest neighbor, knowledge of its morphology is still limited. Due to instrumental limitations of previous missions, a global map of the moon’s topography at high resolution has not existed until now. With the LRO Wide Angle Camera and the Lunar Orbiter Laser Altimeter (LOLA) instrument, scientists can now accurately portray the shape of the entire moon at high resolution.
“Our new topographic view of the moon provides the dataset that lunar scientists have waited for since the Apollo era,” says Mark Robinson, Principal Investigator of the Lunar Reconnaissance Orbiter Camera (LROC) from Arizona State University in Tempe. “We can now determine slopes of all major geologic terrains on the moon at 100 meter scale. Determine how the crust has deformed, better understand impact crater mechanics, investigate the nature of volcanic features, and better plan future robotic and human missions to the moon.”
Called the Global Lunar DTM 100 m topographic model (GLD100), this map was created based on data acquired by LRO’s WAC, which is part of the LROC imaging system. The LROC imaging system consists of two Narrow Angle Cameras (NACs) to provide high-resolution images, and the WAC to provide 100-meter resolution images in seven color bands over a 57-kilometer (35-mile) swath.
The WAC is a relatively small instrument, easily fitting into the palm of one’s hand; however, despite its diminutive size it maps nearly the entire moon every month. Each month the moon’s lighting has changed so the WAC is continuously building up a record of how different rocks reflect light under different conditions, and adding to the LROC library of stereo observations.
Arizona State University has a pan- and zoomable version.
Grace and Peace
From the European Space Agency: Battered Tharsis Tholus volcano on Mars
The latest image released from Mars Express reveals a large extinct volcano that has been battered and deformed over the aeons.
By Earthly standards, Tharsis Tholus is a giant, towering 8 km above the surrounding terrain, with a base stretching over 155 x 125 km. Yet on Mars, it is just an average-sized volcano. What marks it out as unusual is its battered condition.
Shown here in images taken by the HRSC high-resolution stereo camera on ESA’s Mars Express spacecraft, the volcanic edifice has been marked by dramatic events.
At least two large sections have collapsed around its eastern and western flanks during its four-billion-year history and these catastrophes are now visible as scarps up to several kilometres high.
The main feature of Tharsis Tholus is, however, the caldera in its centre.
It has an almost circular outline, about 32 x 34 km, and is ringed by faults that have allowed the caldera floor to subside by as much as 2.7 km.
It is thought that the volcano emptied its magma chamber during eruptions and, as the lava ran out onto the surface, the chamber roof was no longer able to support its own weight.
So, the volcano collapsed, forming the large caldera.
HT: Yahoo News