Three astronauts living on the International Space Station will return home to Earth Sunday (July 1) after spending more than six months in orbit.
NASA astronaut Don Pettit, Russian cosmonaut Oleg Kononenko and European Space Agency astronaut Andre Kuipers are scheduled to undock from the space station in their Russian-built Soyuz capsule at 12:48 a.m. EDT (0448 GMT) Sunday.
The trio is expected to land at 4:14 a.m. EDT (0814 GMT) Sunday on the Central Asian steppes of Kazakhstan.
Sunday, July 1
2 a.m. -- Expedition 31/Soyuz TMA-03M deorbit burn and landing coverage (deorbit burn at 2:19 a.m., landing at 3:15 a.m.)
Update; 1.07.2012 Fotos: Frams Roscosmos
A giant crater left by the impact of a 30-kilometer asteroid three billion years ago was found in western Greenland by a joint team of Russian and EU researchers.
The crater was first discovered in 2009 by geologist Adam Garde who found structural anomalies in rock formations near the town of Maniitsoq, according to an article to be published in Earth and Planetary Science Letters.
However, it took researchers three years to establish that the crater was left by a celestial body and not volcanic activity.
Three billion years of ongoing geological processes wiped away most traces of the impact near Maniitsoq, but the rock anomalies remained, waiting for the researchers to study them.
The crater is 100 kilometers in diameter but under different circumstances the impact trace could have spanned up to 600 kilometers, the study said.
The Earth's largest impact crater, Vredefort in South Africa, is 300 kilometers in diameter. At two billion years, it was also the oldest until the new discovery. Chicxulub Crater in Mexico, believed to be the trace of the asteroid that killed the dinosaurs 65 million years ago, is 170 kilometers in diameter.
The impact of a 30-kilometer asteroid can evaporate an average country and even trigger a new mass extinction event, killing all higher life-forms, geologists said.
The so far oldest (i.e. 2975 million years) impact crater on Earth was found near Maniitsoq (in “my days” - and in Danish - known as Sukkertoppen) in West Greenland. It is the fourth multi-ring crater discovered on Earth, besides Chicxulub, Sudbury, and Vredefort. It is a 100 km-scale, circular structure in the Archaean North Atlantic Craton centred at 65°15′N, 51°50′W near the Maniitsoq town in the Qeqqata municipality in West Greenland. The structure comprises a set of highly unusual geological features that were created during a single event involving intense crushing and heating and are incompatible with crustal orogenic processes. The presently exposed features of the Maniitsoq structure were buried 20–25 km below the surface when this event occurred at about 3000 million years ago, during waning convergent orogeny. These features include: a large aeromagnetic anomaly; a central 35×50 km2 large area of comminuted quartzo-feldspathic material; regional-scale circular deformation; widespread random fractures with featherlike textures; intense fracture cleavage; amphibolite–granite-matrix breccias unrelated to faulting or intrusions; formation and common fluidisation of microbreccias; abundant evidence of direct K-feldspar and plagioclase melting superimposed on already migmatised rocks; deformation of quartz by
Finding sufficient evidence was extremely hard because there is no obvious bowl-shaped crater left to find. Over the 3 billion years since the impact, the land has been eroded down to expose deeper crust 25 km below the original surface. All external parts of the impact structure have been removed, but the effects of the intense impact shock wave penetrated deep into the crust -- far deeper than at any other known crater -- and these remain visible. Because the effects of impact at these depths have never been observed before it has taken nearly three years of painstaking work to assemble all the key evidence. Only around 180 impact craters have ever been discovered on Earth and around 30% of them contain important natural resources of minerals or oil and gas. The largest and oldest known crater prior to this study, the 300 kilometre wide Vredefort crater in South Africa, is 2 billion years in age and heavily eroded. It has taken Adam Garde and his co-workers nearly three years to convince their peers in the scientific community that this is an impact structure, while the mining industry was far more receptive. A Canadian exploration company has been using the impact model to explore for deposits of nickel and platinum metals at Maniitsoq since the autumn of 2011.
Adam A. Garde et al.
Searching for giant, ancient impact structures on Earth: The Mesoarchaean Maniitsoq structure, West Greenland
Earth and Planetary Science Letters
Volumes 337–338, 1 July 2012, Pages 197–210
Five Decades Ago...
Launch pads and towers rose one by one above the scrub land, dotting the shoreline of Florida's East coast. By 1960, the "Missile Firing Laboratory" had become an extension of NASA's Marshall Space Flight Center.
On July 1, 1962, NASA officially activated the Launch Operations Center at the seaside spaceport, granting the center equal status to Marshall and offering the center's new director, Dr. Kurt H. Debus, a direct report to the agency's headquarters in Washington, D.C. The following year the center was renamed to honor the president who put America on the path to the moon.
NASA's John F. Kennedy Space Center has helped set the stage for America's adventure in space for five decades. The spaceport has served as the departure gate for every American manned mission and hundreds of advanced scientific spacecraft. From the early days of Project Mercury to the Space Shuttle Program and International Space Station, from the Hubble Space Telescope to the Mars rovers, the center enjoys a rich heritage in its vital role as NASA's processing and launch center.
As the nation prepares to embark on a new chapter in space exploration, Kennedy will continue to make history as America's spaceport.
There was another glide test of the SpaceShipTwo vehicle today at the Mojave Air and Space Port. A source says that WhiteKnightTwo took off with the spacecraft beneath it at about 6:50 a.m. PDT. SpaceShipTwo landed about an hour later and both vehicles were back in the hangar by 8 a.m.
Writing about the flight on his blog, Virgin Group CEO Richard Branson said this was the first test flight with Virgin Galactic Chief Pilot Dave Mackay at the controls.
It was the second glide flight of SS2 this week. An earlier one took place on Tuesday. There are no flight summaries on the Scaled Composites website for today’s test, but they have posted summaries for the flight earlier in the week. Below is a combined version.
Update 12.49 MESZ: Kleine Probleme verzögern den Start von Delta-4.....
Update 15.15 MESZ: Erfolgreicher Start beim 4.Versuch / Frams vom Start: ULA