New Photo of Moon's North Pole Reveals Spiral Illusion (SPACE.com)

Here's a view of the moon you'll never see from Earth.

NASA scientists created this mosaic by stitching together 983 images of the moon's North Pole region taken by the Lunar Reconnaissance Orbiter (LRO). The LRO robotic probe, which has been mapping the moon from above since 2009, has acquired thousands of wide-angle camera shots of its polar regions. [Photo of the moon's north pole]

Because the mottled moon only tilts on its access at an angle of 1.54 degrees (as compared to Earth's 23.5 degree tilt) some of its surface never sees sunlight. One goal of the LRO mission is to identify these regions of permanent shadow. The probe took the photos in the composite image above at the height of summer in our satellite's northern hemisphere — the time when the pole is best illuminated. Thus, dark areas, such as those along the inside rims of deep craters and the immediate vicinity of the pole, are probably permanently dark.

The craters around the pole appear to spiral out from it. According to Mark Robinson, principle investigator of the LRO team based at Arizona State University, this is an optical illusion. [The Most Amazing Optical Illusions (and How They Work)]

"Imagine a series of very narrow pie slices collected 12 times each day, one after another," Robinson told Life's Little Mysteries, a sister site to SPACE.com. "It takes roughly 360 slices to fill in the whole pie. Each day the sun direction is progressing around the moon, thus the direction that the sun is striking the surface changes. So the shadow directions slowly progress around the moon, thus leading to the illusion."

This story was provided by Life's Little Mysteries, a sister site to SPACE.com. Follow Natalie Wolchover on Twitter @nattyover. Follow Life's Little Mysteries on Twitter @llmysteries, then join us on Facebook.

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Monitor says north army masses in Sudan oil state (Reuters)

KHARTOUM (Reuters) – Satellite images taken on Friday showed northern Sudanese military vehicles including heavy transports and artillery massing in the capital of the conflict-stricken Southern Kordofan state, a monitor said.

Fighting between the northern military and southern-aligned groups has spread across the key north-run oil state since June 5. Tens of thousands have fled the violence, according to the United Nations.

The clashes have also raised tensions at a sensitive time in Sudan, with the south less than three weeks away from becoming an independent country following a January referendum.

"New imagery ... confirms that the Sudan Armed Forces, or SAF, control the town of Kadugli in Sudan's tense border region of South Kordofan, and that thousands of civilians have been displaced," the Satellite Sentinel Project (SSP) said in a report.

The images "show a massing of SAF artillery, light vehicles, and heavy transports of the kinds used to carry tanks, troops, and munitions."

Set up last year by Hollywood actor George Clooney and other activists, the SSP says it seeks to head off renewed fighting and atrocities in Sudan by publishing commercial satellite images collated and analyzed with the help of a U.N. agency.

A spokesman for the northern military was not immediately available to comment on the report. It has previously said its forces were fighting to end an armed rebellion in the state.

Southern Kordofan -- the main oil-producing state that will be left in the north after the south secedes on July 9 -- is home to thousands of fighters who fought against Khartoum during the last civil war, many of them from the Nuba mountains region.

Officials with the south's dominant Sudan People's Liberation Movement have said clashes started when the north tried to disarm fighters there.

Northern officials have blamed the southern-aligned groups for provoking the fighting after an official from the north's ruling National Congress Party was named winner of a state gubernatorial election last month.

The south's independence vote was promised in a 2005 peace deal that ended decades of civil war. That conflict claimed some 2 million lives.

(Reporting Alexander Dziadosz; Editing by Dan Williams)

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