Tuesday, August 30, 2011

Europa, Ganymede and Callisto

Europa, Ganymede and Callisto in a surface comparison.
Images from NASA, JPL.
These are the icy surfaces of three of the Galileian Moons.

Friday, August 5, 2011

Collision may have shaped the Moon

"Differences between the near and far sides of the Moon could be the result of a collision between the Moon and a "Trojan" companion that occurred billions of years ago. That is the conclusion of geophysicists in the US and Switzerland who have done computer simulations on how the Moon would be affected by such a massive impact."
Trojan collision may have shaped the Moon - physicsworld.com

Flowing water may exist on Mars

"Liquid water might exist on Mars today, according to a group of scientists in the US. Images from NASA's Mars Reconnaissance Orbiter (MRO) reveal that dark, narrow, finger-like structures follow slopes in certain regions of the southern hemisphere of the planet during its summer months."
Flowing water may exist on Mars - physicsworld.com

Wednesday, August 3, 2011

Merowe Dam on the Nile

The artificial lake (reservoir) created by the Merowe Dam on the Nile has been photographed by the crew of the International Space Station. This image is recent, dating 5 October 2010. The dam is on the Nile near the Fourth Cataract, in that part of Nubia desert where the river Nile is creating the Great Bend, a contorted path through the bedrocks of Bayuda Massif. The satellite imagery of Google Maps, which is a few years old, shows the region, when the dam was under construction. Using Google, we see the Nile and river banks creating a fertile strip of land with many villages.

We can compare the region before and after the spill gates have been closed.
Comparison shows that the lake created itself through the paleochannes, the old dry riverbeds.


More at