Solscape

Wissenschaftler der Universitäten von Texas und Michigan haben mit Hilfe eines kräftigen Laserblitzes eine Plasmawelle erzeugt, die sich mit einer Geschwindigkeit von 99,997 Prozent der Lichtgeschwindigkeit ausbreitet. Dank einer speziell für diese Studie entwickelten Kamera ließ sich die Bewegung der Welle sogar direkt ablichten. Derartige Plasmawellen könnten unter anderem in einer neuen Generation von Teilchenbeschleunigern eingesetzt werden, glauben die Forscher.
Vollständiger Artikel auf wissenschaft.de

The colossal outpouring of lava thought to have almost totally resurfaced Venus 500 million years ago never happened, a new study says. If correct, it means that a much longer record of Venus’s history is preserved on the planet’s surface. Planetary scientists estimated the age of Venus’s surface after studying radar mapping data from NASA’s Magellan spacecraft, which operated in the early 1990s. Assuming Venus was exposed to the same rain of asteroids and comets that the other planets experienced, they expected Magellan would spot about 5000 craters on the planet’s surface. But they found only about 1000, suggesting that the planet’s surface is actually very young – perhaps 500 million to 1 billion years old. And those craters appear remarkably well preserved, unaltered by erosion or other geological processes. The most popular explanation is that a brief but enormous episode of volcanism blanketed most of the planet in a layer of lava 1 to 3 kilometres deep – thick enough to bury all of the craters made before that time. Now, a new analysis of Magellan data suggests that such a deep layer of solidified lava cannot be present on the surface, casting doubt on the “catastrophic resurfacing” hypothesis.
Abstract: Venus was not catastrophically resurfaced

The dust that condensed to form the sun, the Earth and the stuff of human bodies has long been thought to have originated in violent explosions of giant stars. But these explosions – called supernovae – can’t account for all the dust in the cosmos. Now, observations with NASA’s Spitzer Space Telescope, led by University of Minnesota astrophysicists, have found cosmic dust where it had never been found before. The finding implies that the deaths of smaller stars may have supplied the early dust that seeded the myriad stars like our sun, and produced dust more efficiently than the big guns.

New observations of star cluster by U of M researchers help settle the dust on sun’s origin

Stellar Populations and Mass-Loss in M15: A Spitzer Detection of Dust in the Intra-Cluster Medium

The infrared surveyor AKARI, a Japan Aerospace Exploration Agency (JAXA) mission with ESA participation, is nearing the completion of its first scan of the entire sky. During this phase of the mission, it has supplied the largest wavelength coverage of the Large Magellanic Cloud to date, and provided fascinating new images of this galaxy. The Large Magellanic Cloud is a neighbouring galaxy to the Milky Way, the galaxy to which our Solar System belongs. It is located extremely close by astronomical standards, at a distance of 160.000 light years, and it contains about 10 thousand million stars, about one tenth of our Galaxy’s stellar population.
Images

The surviving portion of the Deep Impact space probe that watched its “impactor’s” collision with comet Tempel 1 on July 4, 2005, is being sent on a mission to study another comet. NASA announced Tuesday that it has accepted a proposal by the University of Maryland, which developed and manages Deep Impact, to send the vehicle on an extended mission to intercept Comet Boethin. The new mission will not involve a collision. Instead, Deep Impact will pass Boethin in December 2008 so its instruments can examine the comet. The spacecraft remains healthy and researchers are hoping to gather information from Boethin that will help to understand further of how comets formed and evolved and if they played a role in the emergence of life on Earth.

Deep Impact Legacy Site

Auch die Nordsee ist für spektakuläre Erlebnisse gut: Kieler Meeresforscher sind erstmals in einen Krater getaucht, der bei einem Gasausbruch am Meeresgrund entstanden war. Nach dem Abstieg durch einen Strudel von Methanblasen fanden sie einen dicht besiedelten Kraterboden vor.

http://www.ifm-geomar.de/index.php?id=3387

Nur bei wenigen Tierarten können sich Individuen selbst im Spiegel erkennen. Amerikanische Forscher haben nun Hinweise darauf gefunden, dass auch Elefanten zu dieser exklusiven Gruppe gehören. Bei ihren Versuchen mit drei Zootieren tastete zumindest eines nach einem Farbklecks auf seinem Kopf, nachdem es sein Spiegelbild gesehen hatte. Schon länger wurde vermutet, dass Elefanten über derartige Fähigkeiten verfügen könnten. Ihr komplexes Sozialverhalten, ihr wohlbekanntes altruistisches Verhalten und natürlich ihr großes Hirn machen Elefanten zu logischen Kandidaten für Spiegeltests. Zu den übrigen erfolgreich getesteten Arten gehören Menschenaffen, Große Tümmler und auch Elstern. Bisherige Tests mit relativ kleinen Spiegeln außerhalb der Rüsselreichweite waren stets negativ ausgefallen. Joshua Plotnik von der Emory University in Atlanta und seine Kollegen konfrontierten nun drei weibliche Asiatische Elefanten mit einem 2,5 mal 2,5 Meter großen und stabilen Spiegel, den die Tiere ausführlich untersuchen konnten. Nachdem sie dies getan hatten, schienen alle drei Elefantendamen das Spiegelbild regelrecht zu testen: so bewegten sie Rüssel, Kopf und Körper immer wieder hin und her oder fraßen eigens herangeschafftes Futter nur vor dem Spiegel. Und zumindest ein Tier, die 34-jährige “Happy”, bestand einen besonders strengen Selbsterkennungstest. Plotnik malte der Elefantendame einen hellen Fleck auf die Kopfseite außerhalb ihres Blickfelds. Nachdem sich “Happy” samt Fleck im Spiegel gesehen hatte, tastete sie immer wieder mit dem Rüssel nach der entsprechenden Kopfseite. Dieses Verhalten blieb jedoch aus, als die Forscher lediglich eine farblose Flüssigkeit verwendeten.
Emory University

http://www.elephantvoices.org/

Shuttle astronauts will make one final house call to the Hubble Space Telescope as part of a mission to extend and improve the observatory’s capabilities. NASA Administrator Michael Griffin announced plans for a fifth servicing mission to Hubble today during a meeting with agency employees at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The 11-day rehab mission, likely launching early May 2008 using space shuttle Discovery, would keep Hubble working until about 2013. Its batteries and gyroscopes, which are used to point the telescope, are degrading and they will now be replaced. The shuttle crew will also install two new instruments: the Wide Field Camera 3 (WFC3), and the Cosmic Origins Spectrograph (COS). The new instruments will improve significantly Hubble’s ability to probe distant, faint objects in the early Universe. Griffin also announced the astronauts selected for the mission. Veteran astronaut Scott D. Altman will command the final space shuttle mission to Hubble. Navy Reserve Capt. Gregory C. Johnson will serve as pilot. Mission specialists include veteran spacewalkers John M. Grunsfeld and Michael J. Massimino and first-time space fliers Andrew J. Feustel, Michael T. Good and K. Megan McArthur. Altman will be making his fourth spaceflight and his second trip to Hubble. He commanded the STS-109 Hubble servicing mission in 2002. Grunsfeld, an astronomer, will be making his third trip to Hubble and his fifth spaceflight. He performed five spacewalks to service the telescope on STS-103 in 1999 and STS-109 in 2002. Massimino will be making his second trip to Hubble and his second spaceflight. He performed two spacewalks to service the telescope during the STS-109 mission in 2002.

An apparent discrepancy in the Big Bang theory of the universe’s evolution has been reconciled by astrophysicists examining the movement of gases in stars. Professor John Lattanzio from Monash’s School of Mathematical Sciences and Director of the Centre for Stellar and Planetary Astrophysics said the confusion surrounding the Big Bang revolved around the amount of the gas Helium 3 in the universe. “The Big Bang theory predicts a certain amount of Helium 3 in the universe”, Professor Lattanzio said. “The trouble is, low mass stars (about one to two times the size of our sun) also make Helium 3 as a side product of burning the hydrogen in their cores.” It’s been thought that when the star becomes a giant it mixes the Helium 3 to its surface and, near the end of its life, spews the Helium 3 into space just before it becomes a planetary nebula. But there are inconsistencies with the amount of Helium 3 predicted to be in the universe and the amount that’s actually there; there’s much less than expected. Some scientists have theorised that the rapid rotation of low mass stars destroys the Helium 3 they produce. But computer models that have included this rotation, while showing some destruction of Helium 3, have not been able to reconcile the Big Bang theory. Professor Lattanzio, in collaboration with Dr. Peter Eggleton and Dr. David Dearborn from the Lawrence Livermore National Laboratories in the US, ran 3D computer models of a red giant’s life on some of the world’s fastest computers to investigate whether there was some sort of gaseous mixing occurring in stars that destroyed Helium 3. Their findings have been published in the new issue of the international journal “Science”. Near the end of a star’s life there is a “core flash” and it was at around this time that the computer models revealed a small instability in the movement of the gases in the star. “When we looked at this in 3D we found this hydrodynamic instability caused mixing and destroyed the Helium 3 so that none was released into space,” Professor Lattanzio said. “This apparent problem with the Big Bang has been solved – the Helium 3 in the universe comes from the Big Bang and low mass stars, although they produce Helium 3, they do not release any into the universe because they destroy it.”
Scientists crack open stellar evolution

Deep Mixing of He-3: Reconciling Big Bang and Stellar Nucleosynthesis

Ohio State University geologists have isolated complex organic molecules from 350-million-year-old fossil sea creatures – the oldest such molecules yet found. The molecules may have functioned as pigments, but the study offers a much bigger finding: an entirely new way to track how species evolved.
http://researchnews.osu.edu/archive/foscolor.htm