Lake Superior, der zweitgrößte See der Erde, wird nicht nur kleiner, sondern auch wärmer. Forscher beunruhigt, dass die Wassermenge seit 1999 ständig unter den Durchschnittswerten der letzten 40 Jahre geblieben ist und in diesem Jahr sogar einen Tiefstwert erreichte. Hinzu kommt, dass sich das Oberflächenwasser des besonders kalten Sees auf bis zu 24 Grad Celsius erwärmt hat. Die ökologischen Folgen dieser ganzen Entwicklung sind noch ungewiss. Der Lake Superior im Grenzgebiet zwischen den USA und Kanada ist der wichtigste Trinkwasser-Speicher der Region.
Shrinking Lake Superior Also Heating Up
Solscape
Crystals On Meteorite Reveal Clues To Early Solar System Evolution
A new study has uncovered tiny zircon crystals in a meteorite originating from Vesta (a large asteroid between Mars and Jupiter), shedding light on the formation of planetesimals (small astronomical objects that form the basis of planets). To date, studying zircons in eucrites – meteorites formed by volcanic activity – has been difficult due to impact-induced fracturing and their small size; typically less than five microns. Most eucrites are formed within the asteroid belt that orbits between Mars and Jupiter, a heap of astronomical debris from the earliest epoch of the solar system. In a study published in the recent issue of „Science“, researchers collected samples from eucrites found in Antarctica believed to have originated from Vesta. The researchers used new technology to reveal that asteroid’s boiling rock turned solid and crystallized within less than 10 million years of solar system formation.
Cassini data points to origin of Saturn's G ring
Scientists studying data from NASA’s Cassini spacecraft have discovered what they thought is the origin for one of the more unusual rings surrounding the planet Saturn. In a paper published in the journal „Science“, they said Saturn’s G ring is likely linked to an arc of relatively large ice particles in a part of the ring’s inner edge, which are kept in line by the gravitational influence of Saturn’s moon Mimas. Collisions with micrometeoroids create smaller particles, which are then spread throughout the ring by plasma in Saturn’s magnetic field.
https://solarsystem.nasa.gov/news/12393/cassini-finds-possible-origin-of-one-of-saturns-rings/
Video: Phoenix Launch – August 4
A Delta II rocket lit up the early morning sky over Cape Canaveral Air Force Station in Florida as it carried the Phoenix spacecraft on the first leg of its journey to Mars. The powerful three-stage rocket with nine solid rocket motors lifted off on Saturday at 5:26 a.m. EDT.
Uncovering the Veil Nebula
The Hubble Space Telescope has photographed three magnificent sections of the Veil Nebula – the shattered remains of a supernova that exploded some 5 to 10.000 years ago. The new Hubble images provide beautiful views of the delicate, wispy structure resulting from this cosmic explosion.
https://esahubble.org/news/heic0712/
Impact Craters in Tyrrhena Terra
The High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express obtained images of the Tyrrhena Terra region on Mars. Tyrrhena Terra is part of the ancient, heavily cratered southern Martian highlands. The region is located north of Hellas Planitia, the largest impact basin on Mars.
https://www.esa.int/Science_Exploration/Space_Science/Mars_Express/Impact_Craters_in_Tyrrhena_Terra
Tiny asteroid found trailing after Mars
A new space rock has been found that devotedly travels around with Mars as it orbits the Sun, bringing the total number of such „groupies“ to four. The asteroid, called 2007 NS2, was discovered by astronomers at the La Sagra Observatory in southern Spain on July 14, 2007. Based on its brightness, it is estimated to be about one kilometre across. It follows Mars in its orbit, occupying the L5 spot, which lags the Red Planet by 60° as it moves around the Sun. It shares L5 with two other objects, while a fourth object orbits 60° ahead of Mars at the L4 point. Objects that wander into the L4 and L5 points of a planet tend to be confined there by the combined gravity of the planet and the Sun. Mars is one of just three planets known to have such „Trojan“ objects in its orbit. About 2200 Trojans are known to accompany Jupiter in its orbit, and a handful have been discovered in Neptune’s orbit as well.
List Of Martian Trojans
Supergiant Star Spews Molecules Needed for Life
University of Arizona astronomers who are probing the oxygen-rich environment around a supergiant star with one of the world’s most sensitive radio telescopes have discovered a score of molecules that include compounds needed for life.
Mysteries Of Antarctic Mountains Revealed
The 3.000-kilometer-long Transantarctic Mountains are a dominant feature of the Antarctic continent, yet up to now scientists have been unable to adequately explain how they formed. In a new study, geologists led by Michael Studinger from Columbia University’s Lamont-Doherty Earth Observatory report that the mountains appear to be the remnant edge of a gigantic high plateau that began stretching and thinning some 105 million years ago, leaving the peaks curving along the edge of a great plain.
Michael Studinger’s Homepage on the Transantarctic Mountains
Mars Rovers Braving Severe Dust Storms
Having explored Mars for three-and-a-half years in what were missions originally designed for three months, NASA’s Mars rovers are facing perhaps their biggest challenge. For nearly a month, a series of severe Martian summer dust storms has affected the rover Opportunity and, to a lesser extent, its companion, Spirit. The dust in the Martian atmosphere over Opportunity has blocked 99 percent of direct sunlight to the rover, leaving only the limited diffuse sky light to power it. Scientists fear the storms might continue for several days, if not weeks.
https://mars.nasa.gov/mer/gallery/press/opportunity/20070720a.html