A river runs through it — on Titan

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.”

Credit: d
Credit: NASA/JPL/ESA/ASI — http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageID=4700

HT: Clastic Detritus

Grace and Peace

Earth at Night

NASA recently released Earth at Night, a global view of the planet at night, with city lights, oilfield flares, night time fishing fleets, and auroras.

Google has created a wonderful viewer for this data, which can be found at its Earth at Night 2012 site.

Earth at Night zoomed out to show the entire planet
Earth at Night zoomed out to show the entire planet
Northeast United States
Northeast United States
Montana, where night skies are always black
Montana, where night skies are always black
Netherlands, Belgium, and northern France, where you would be lucky to see Jupiter on a cloudless night
Netherlands, Belgium, and northern France, where you would be lucky to see Jupiter on a cloudless night
Korean Peninsula. Note the lights from fishing fleets off the coast of South Korea. Note also how dark North Korea is.
Korean Peninsula. Note the lights from fishing fleets off the coast of South Korea. Note also how dark North Korea is.

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Lunar topography

http://lroc.sese.asu.edu/news/index.php?/archives/484-Lunar-Topography-As-Never-Seen-Before!.html

From NASA: LRO Camera Team Releases High Resolution Global Topographic Map of Moon.

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.

HT: Astronomy Picture of the Day 11/18/2011.

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Seven years of Opportunity

The rover Opportunity has been on the surface of Mars for over seven years now. From Astronomy Picture of the Day for January 29th: Opportunity at Santa Maria Crater.

Credit: Mars Exploration Rover Mission, NASA, JPL, Cornell

The panorama is much more detailed on the APOD site.

The description from APOD:

Celebrating 7 years on the surface of the Red Planet, Mars exploration rover Opportunity now stands near the rim of 90 meter wide Santa Maria crater. Remarkably, Opportunity and its fellow rover Spirit were initially intended for a 3 month long primary mission. Still exploring, the golf cart-sized robot and shadow (far right) appear in the foreground of this panoramic view of its current location. The mosaic was constructed using images from the rover’s navigation camera. On its 7 year anniversary, Opportunity can boast traversing a total of 26.7 kilometers along the martian surface. After investigating Santa Maria crater, controllers plan to have Opportunity resume a long-term trek toward Endurance crater, a large, 22 kilometer diameter crater about 6 kilometers from Santa Maria. During coming days, communication with the rover will be more difficult as Mars moves close to alignment with the Sun as seen from planet Earth’s perspective.

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Ice on the Moon

From Astronomy Picture of the Day 10/25/2010: Water Ice Detected Beneath Moon’s Surface

Blue is hydrogen-rich (probably water ice) and red is hydrogen-poor.

The explanation from the APOD site:

Is there enough water on the moon to sustain future astronauts? The question has important implications if humanity hopes to use the Moon as a future outpost. Last year, to help find out, scientists crashed the moon-orbiting LCROSS spacecraft into a permanently shadowed crater near the Moon’s South Pole. New analyses of the resulting plume from Cabeus crater indicate more water than previously thought, possibly about six percent. Additionally, an instrument on the separate LRO spacecraft that measures neutrons indicates that even larger lunar expanses — most not even permanently shadowed — may also contain a significant amount of buried frozen water. Pictured above from LRO, areas in false-color blue indicate the presence of soil relatively rich in hydrogen, which is thought likely bound to sub-surface water ice. Conversely, the red areas are likely dry. The location of the Moon’s South Pole is also digitally marked on the image. How deep beneath the surface the ice crystals permeate is still unknown, as well as how difficult it would be to mine the crystals and purify them into drinking water.

NASA going nowhere?

From Yahoo! News: Senators to NASA chief: Go somewhere specific

President Obama’s budget proposal would axe NASA’s planned trip to the moon. So where should NASA send astronauts? The long-term goal is to send astronauts to Mars, but what are good shorter-term objectives?

Here are two items that caught my attention regarding a future trip to Mars:

  • Using inflatable spaceship parts
  • Technological advances that would cut travel time to Mars down from three months to “a matter of days.”

On a humorous note, NASA has a graphic that shows possible destinations to send astronauts in upcoming years. I’m not sure that “Sun” is all that good of an idea.

Credit: NASA

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