Solscape

A new incredible photograph shows Saturn’s potato-shaped moon Janus posing above the planet’s cloudy atmosphere. Janus is only 181 kilometers across, and it shows the scars of many impacts with other objects. Like Saturn’s other smaller moons, Janus could be covered with a layer of fine, dust-sized icy material. The Cassini spacecraft took the photo on September 25, 2006, when it was only 145.000 kilometers from Janus.
http://photojournal.jpl.nasa.gov/catalog/PIA08296

The world’s largest river basin, the Amazon, once flowed from the Atlantic Ocean to the Pacific – opposite to its present direction – according to research by a geology graduate student and his advisor at the University of North Carolina at Chapel Hill. Graduate student Russell Mapes set out in 2004 to study the speed at which sediment in the Amazon travels from the Andes mountains, in the present headwaters of the river, to the Atlantic. While studying sedimentary rocks in the river basin he discovered something else – ancient mineral grains in the central part of South America that could only have originated in now-eroded mountains in the eastern part of the continent. If the Amazon had continuously flowed eastward, as it does now, Mapes would have found much younger mineral grains in the sediments from the Andes. Mapes explains that these sediments of eastern origin were washed down from a highland area that formed in the Cretaceous Period, between 65 million and 145 million years ago, when the South American and African tectonic plates separated and passed each other. That highland tilted the river’s flow westward, sending sediment as old as 2 billion years toward the center of the continent. A relatively low ridge, called the Purus Arch, which still exists, rose in the middle of the continent, running north and south, dividing the Amazon’s flow – eastward toward the Atlantic and westward toward the Andes. Toward the end of the Cretaceous, the Andes started growing, which sent the river back toward the Purus Arch. Eventually, sediment from the mountains, which contained mineral grains younger than 500 million years old, filled in the basin between the mountains and the arch, the river breeched it and started its current flow. Previous research has identified a reverse flow, but only in segments of the river. Mapes traversed about 80 percent of the Amazon basin.
Abstract: Evidence For A Continent Scale Drainage Inversion In The Amazon Basin Since The Late Cretaceous

Diagram

Mit Hilfe der europäischen H.E.S.S.-Teleskope in Namibia entdeckten Forscher hochenergetische Gammastrahlung, die aus dem Zentrum der riesigen Radiogalaxie M87 kommt. Wegen der beobachteten Schwankungen der Strahlung kommt als Ursprung eigentlich nur ein Ort in Frage: ein Schwarzes Loch im Zentrum der Galaxie.

Gamma-Strahlung vom Rand eines supermassiven schwarzen Lochs entdeckt

A summer thunderstorm often provides much-needed rainfall and heat wave relief, but others bring large hail, destructive winds, and tornadoes. Now with the help of NASA satellite data, scientists are gaining insight into the distribution of such storms around much of the world.
Tropical Rainfall Measuring Mission

Lightning and Electricity Research

A new photograph from the Spitzer Space Telescope shows how supernova remnant Cassiopeia A evolved over time. The original star contained 15 to 20 times the mass of our Sun, and was made up of concentric shells of elements. The lightest elements, like hydrogen, were in the outermost shell, while the heaviest elements sunk to the centre. The shells of the exploded material match up quite well with the original layers in the star before it detonated as a supernova.
Press release

Images and Videos

New images taken with Hubble’s Advanced Camera for Surveys (ACS) in November 2005 and September 2006 show the evolution of the light echo around the star V838 in the constellation of Monoceros.
Hubble’s Latest Views of Light Echo from Star V838 Monocerotis

Ancient human footprints discovered in the Mexican desert may be among the oldest in the Americas, researchers said on Wednesday. The 13 footprints found in Cuatro Cienegas in the northern state of Coahuila are fossilized in stone less than an inch deep and are around the age of the oldest known footprints in North or South America – they could be between 10.000 and 15.000 years old. The oldest discovered human footprints in the New World are in Monte Verde, Chile and are believed to be around 13.000 years old. The earliest known hominid tread marks are the Laetoli footsteps in Tanzania. At 3.7 million years old, they far predate the advent of homo sapiens.
Source: Reuters

Astronomers have discovered two of the most distant galaxies ever seen, when the Universe was only 700 million years old. The galaxies were first discovered as part of the Hubble Space Telescope’s Deep Field Survey, which looked into the distant Universe. Astronomers then did follow-on observations with the Spitzer Space Telescope to confirm their distance and age. The galaxies are between 50-300 million years old, and have only 1% of the mass of our own Milky Way.

Astronomers weigh 200-million-year-old baby galaxies

NASA’s twin Solar Terrestrial Relations Observatories mission, known as STEREO, successfully launched on Wednesday at 8:52 p.m. EDT from Cape Canaveral Air Force Station, Florida. STEREO’s nearly identical twin, golf cart-sized spacecraft will make observations to help researchers construct the first-ever three-dimensional views of the sun.
http://www.nasa.gov/home/hqnews/2006/oct/HQ_06340_STEREO_launch.html

Yesterday, October 26, 2006, was Spirits 1.000th sol on Mars, that’s 910 sols longer than the mission was planned for. A sol is equal to 24 hours, 39 minutes, and 35 seconds. The rover Spirit took a panorama of its winter home on the Martian surface. The 360-degree image is called the McMurdo panorama and comes from the Pancam on Spirit. The image approximates the natural colors on Mars.
Here’s the NASA story with a high resolution image of the McMurdo panorama:
‘McMurdo’ Panorama from Spirit’s ‘Winter Haven’