                  |
 Net World Directory Your personal directory for the internet | ||
| Net World Directory: Archives of astronomy blog |
 | ||
Archives Of Astronomy Blog From NetworlddirectorySubscribe To Astronomy Blog RSS Feed 
Origin Of Neptune's Oddball Moon Triton
Neptune's largest moon, Triton. Image credit: NASA
In the May 11 issue of the journal Nature, planetary researchers Craig Agnor of the University of California, Santa Cruz, and Douglas Hamilton of the University of Maryland describe a new model for the capture of planetary satellites involving a three-body gravitational encounter between a binary and a planet. As per this scenario, Triton was originally a member of a binary pair of objects orbiting the Sun. Gravitational interactions during a close approach to Neptune then pulled Triton away from its binary companion to become a satellite of Neptune. "We've found a likely solution to the long-standing problem of how Triton arrived in its peculiar orbit. In addition, this mechanism introduces a new pathway for the capture of satellites by planets that may be relevant to other objects in the solar system," said Agnor, a researcher in UCSC's Center for the Origin, Dynamics, and Evolution of Planets......... Posted by: Brooke Permalink Source The Planisphere Watch For Astronomers
The watch features a durable brass case, scratch resistant crystal dome lens, Japanese quartz movement and a "Super Luminescent" dial that glows for 2 to 3 hours to enable you to view in dark. The mini Planisphere on the dial add to its astronomic-looks. The watch sells for just $50 at ThinkGeek. Cool factor: Astronomy Feature & Cheap price......... Posted by: Brooke Permalink Source New Movies Of TitanNew views of the most distant touchdown ever made by a spacecraft are being released recently by NASA, the European Space Agency and the University of Arizona. The movies show the dramatic descent of the Huygens probe to the surface of Saturn's moon Titan on Jan. 14, 2005.The movies were put together with data collected by the Descent Imager/Spectral Radiometer instrument during the probe's 147-minute plunge through Titan's thick orange-brown atmosphere to a soft sandy riverbed. The Descent Imager/Spectral Radiometer was funded by NASA. The data were analyzed for months after the landing and represent the best visual product obtained from the Huygens mission. It is the most realistic way yet to experience the Huygens probe landing. The movie "View from Huygens on Jan. 14, 2005," provides in 4 minutes and 40 seconds of what the probe actually "saw" during the 2.5 hours of the descent and touchdown. Titan Descent Data Movie with Bells and Whistles. "At first, the Huygens camera just saw fog over the distant surface," said Erich Karkoschka, team member at the University of Arizona, Tucson, and creator of the movies. "The fog started to clear only at about 60 kilometers [37 miles] altitude, making it possible to resolve surface features as large as 100 meters [328 feet]," he said. "But only after landing could the probe's camera resolve little grains of sand millions and millions of times smaller than Titan. A movie is a perfect medium to show such a huge change of scale"......... Posted by: Brooke Permalink Source Tibet Provides Passage For Chemicals
Learning how water vapor reaches the stratosphere can help improve climate prediction models. Similarly, understanding the pathways that ozone-depleting chemicals can take to reach the stratosphere is essential for understanding future threats to the ozone layer, which shields Earth from the sun's harmful ultraviolet rays. Scientists from the Georgia Institute of Technology, Atlanta; NASA's Jet Propulsion Laboratory, Pasadena, Calif.; and the University of Edinburgh, Scotland, performed their analysis using data from the Microwave Limb Sounder instrument on NASA's Aura spacecraft, combined with data from NASA's Aqua and Tropical Rainfall Measuring Missions. The team collected more than 1,000 measurements of high concentrations of water vapor in the stratosphere over the Tibetan Plateau and the Asian monsoon region. The measurements were collected during August 2004 and August 2005, during the height of monsoon season. Through the use of wind data and NASA atmospheric models, they found the water vapor originated over Tibet, just north of the Himalayan mountain range......... Posted by: Sarah Permalink Source Venus Express Has Reached Final Orbit
Venus Express will make unprecedented studies of the largely unkown phenomena taking place in the Venusian atmosphere. Its suit of instruments will also dig into the interaction between the solar wind and the planetary environment. Finally, the mission will gather glimpses about the planet's surface, striclty coupled with the dense atmosphere. Credits: ESA - AOES Medialab Less than one month after insertion into orbit, and after sixteen loops around the planet Venus, ESA's Venus Express spacecraft has reached its final operational orbit on 7 May 2006. Already at 21:49 CEST on 6th May, when the spacecraft communicated to Earth through ESA's ground station at New Norcia (Australia), the Venus Express ground control team at ESA's European Spacecraft Operations Centre (ESOC) in Darmstadt (Gera number of) received advanced confirmation that final orbit was to be successfully achieved about 18 hours later. Launched on 9 November 2005, Venus Express arrived to destination on 11 April 2006, after a five-month interplanetary journey to the inner solar system. The initial orbit - or 'capture orbit' - was an ellipse ranging from 330 000 kilometres at its furthest point from Venus surface (apocentre) to less than 400 kilometres at its closest (pericentre). As of the 9-day capture orbit, Venus Express had to perform a series of further manoeuvres to gradually reduce the apocentre and the pericentre altitudes over the planet. This was achieved by means of the spacecraft main engine - which had to be fired twice during this period (on 20 and 23 April 2006) - and through the banks of Venus Express' thrusters - ignited five times (on 15, 26 and 30 April, 3 and 6 May 2006)......... Posted by: Brooke Permalink Source Teamwork And Task Performance For The Moon And Mars
NEEMO-9 astronaut/aquanaut Nicole P. Stott and University of Cincinnati physician Tim Broderick perform survey and mapping activities to record the coordinates of landmarks of interest around Aquarius during an EVA.
Between daily living, telemedicine activities and moon-walking simulations, participants in the NASA Extreme Environment Mission Operations (NEEMO) 9 project helped National Space Biomedical Research Institute (NSBRI) scientists study performance ability, problem-solving and team cohesion issues that could affect long-duration space flights. "The NEEMO undersea mission is a similar experience in key ways to what future space travelers might encounter," said Dr. David Dinges, team leader of NSBRI's Neurobehavioral and Psychosocial Factors Team and principal investigator on the project. "Crew members live and work together in a small space, isolated from the outside world, and must effectively perform difficult tasks at a high level of alertness, both as individuals and a team." Clinician astronaut, Dr. Dave Williams of Canada, led the NEEMO undersea excursion in Aquarius off the Florida coast. Aquarius, the only underwater laboratory in the world, is owned and funded by the National Oceanic and Atmospheric Administration and operated by the University of North Carolina at Wilmington. Two additional astronauts, Nicole Stott and Ron Garan, and Dr. Tim Broderick, a doctor at the University of Cincinnati, rounded out the crew. Jim Buckley and Ross Hein of UNCW provided undersea engineering support......... Posted by: Brooke Permalink Source Rainbow of a Galaxy
NASA's Spitzer, Hubble, and Chandra space observatories teamed up to create this multi-wavelength, false-colored view of the M82 galaxy. The lively portrait celebrates Hubble's "sweet sixteen" birthday......... Posted by: Brooke Permalink Source World Wind Add-on
NASA World Wind with my Observatories add-on data layer CREDIT: Stuart/NASA World Wind mentioned NASA World Wind in my prior post and said that it was possible to add data layers. I have been exploring the add-on possibilities and noticed that the. Telescopes add-on doesn't seem to be available at the moment. So, I have started to put together my own Observatory add-on with individual icons for each observatory and links to home pages. Below is a screenshot of Europe to show what it looks like so far......... Posted by: Brooke Permalink Source How Long Is A Day On Saturn?
This is a whole 8 minutes slower than NASA Voyager results from the early part of 1980s, and slower than prior estimates from another Cassini instrument. The magnetometer results provide the best estimate of the Saturn day to date, because it can see deep inside Saturn. Planets rotate around their "spin" axes as they orbit about the Sun. Rocky planets like the Earth and Mars have rotation periods that remain quite constant and are easy to measure because we can see the surfaces rotate. Gaseous planets do not have a solid surface to track and are not as rigid as rocky planets. Thus, their periods may change more than those of rocky planets while being less easy to measure. Researchers have sought to use proxy measures such as the repetition rate of radio signals or the period of the rotation of the direction of the magnetic axis of the planet. However for Saturn this has proved difficult because prior missions could not detect a period in the magnetic field measurements and whilst radio data have shown a period - it has changed in the time between prior missions and Cassini......... Posted by: Brooke Permalink Source Students Help Cryosat-2 Arctic Campaign
"Having these students take part in CryoSat campaign activities is the result of a unique collaboration between ESA and the Climate Change College," said Malcolm Davidson, CryoSat Validation Manager. "The students will contribute to the fieldwork by taking and analysing snow and ice samples on the ground along side the UK researchers already in place. Not only will the students gain first-hand knowledge of how important scientific fieldwork is carried out, but they will also gain a deeper insight into the importance of ESA's CryoSat-2 mission to better monitor and understand environmental changes, in particular, changes in ice cover in the polar regions. It should prove a wonderful experience." The go-ahead to build and launch the CryoSat-2 mission came in February 2006 after the loss of the first CryoSat last October due to a launch failure. The mission's objectives remain the same as before - to measure ice thickness on both land and sea very precisely to provide conclusive proof as to whether there a trend towards diminishing polar ice cover, furthering our understanding of the relationship between ice and global climate......... Posted by: Tyler Permalink Source |
||
| Net World Directory: Navigation |