July 30th Radio Show online: Mercury, Saturn, and the Outer Solar System

The July 30th radio show is now online and available here. This show marked the end of our trip through the Solar System, and I discussed the latest news concerning the innermost planet in the Solar System (Mercury), as well as one of the outer ones (Saturn), and recent measurements concerning the edge of the Solar System. In detail I covered:

• News: Thank you to Home Depot for donating a new and much-needed roof to the Custer Institute and Observatory; Phoenix Mars Lander producing 3D image of surrounding area (link,3D map); NASA starts funding a GPS program for the Moon (link); NASA invites media for a demo of Lunar Surface Manipulator concept on August 1st; NASA to hold media briefing for final Hubble servicing mission September 8-9; NASA and USDA sign an agreement for the USDA to conduct research on the International Space Station; NASA develops a new webpage to show the latest satellite imagery of fires on the Earth; NASA's Kennedy Spaceflight Center hosts a program for Florida high school students to work on challenges related to returning to the Moon; 2008 General Aviation Technology Challenge to be held August 4-10 in Santa Rosa, CA; NASA's 50th Anniversary honored at EAA AirVenture 2008 air show in Oshkosh, WI July 28 - Aug 3; NASA successfully tests a parachute designed to slow down the descent of the first-stage motor from the Ares I rocket, the successor to the space shuttle; congratulations to NASA's programmers on the Data-Parallel Line Relaxation and Adaptive Modified Gerchberg-Saxton Phase Retrieval programs for winning NASA's 2007 Software of the Year award; ongoing dispute between NSF and local residents concerning the Advanced Technology Solar Telescope to be located on top of Mauna Kea; editorial in July 23rd New York Times calling for development of solar power stations in space (link); positive movie review of WALL-E in July 24th edition of Nature magazine (I concur whole-heartedly); new exhibit at Museum of History of Science in Oxford, UK on Ferdinand Verbiest - court astronomer in China in the late 1600s; Perseid Meteor shower to peak on August 12th, expected to be a good one.
• Calendar of upcoming Astronomy events in the greater Poughkeepsie / New York City area
• Mercury: The closest planet to the Sun, it is one of the least studied planets in the Solar System because it is difficult to get space craft there (it takes a lot of fuel to decelerate a space craft launched from the Earth to get so close to the Sun. A space craft launched from the Earth will stay in the Earth's orbit if it doesn't fire rockets.) However, NASA recently launched a space craft called MESSENGER to study Mercury, and while it isn't in orbit around this planet just yet, on January 14th, 2008 it did it's first flyby during which it made some measurements that revealed some exciting new information about this planet that were summarized in the July 4th, 2008 edition of Science magazine. It discovered that the smooth surface in the Caloris Region basin is likely the result of volcanic activity on Mercury - long after such volcanism was expected to end; Mercury's magnetic field is generated by an active dynamo in the core, and not the remnant of a magnetic field formed earlier that was locked into its crust as previously thought; the cooling of Mercury's core shrunk so much that is caused huge wrinkles in the crust; and made the first observations of charged particles around Mercury kicked off the surface by the Solar Wind and sunlight (link 1, link 2, link 3).
• Saturn: In my opinion, one of the most beautiful planets in the Solar System with its extensive ring system and plentiful moons, Saturn and its surroundings have been studied extensively over the passed 4 years by the recently-extended Cassini spacecraft. Recent results include a temporal and altitude temperature variation in Saturn's atmosphere over its equator likely the equivalent of seasonal variations seen on Earth; a vortex over the south pole of Saturn; a secondary aurora on Saturn resulting from charged particles produced by volcanism on its moon (link); extremely powerful lightning on Saturn the source of observed bursts of radio emission seen from this planet (link); Saturn's innermost A-ring absorbs material ejected by geysers on Enceladus; the different velocity between the dust and gas ejected by the geysers on Enceladus (dust slower, gas faster) due to dust bouncing off the walls of the fractures in the surface of Enceladus from which they are produced (link); Cassini flyby through the material ejected from Enceladus detects organic compounds (link) - leading to suggestions that their might be life on this moon (link); common black coating found on the surface of many of Saturn's icy moons; variability and fine structure in Saturn's F-ring caused by moonlets in this ring (link); discovery of partial ring system around Saturn's moon Rhea (article); Saturn's moon Titan believed to more liquid hydrocarbons on its surface than present in the Earth (link) and has a rapidly changing rotation period likely the result of an internal water ocean.
• Pluto: It might not be classified as a planet any longer, but it is still an interesting object to study. NASA launched a space craft a few years ago called New Horizons to study it in detail, and it appears that Pluto's atmosphere will still be around when it arrives.
• Edge of the Solar System: The sun resides in the Milky Way, and one edge of the Solar System is defined where the solar wind - the stream of highly energetic particles produced in the Sun's corona - is decelerated by the surrounding interstellar medium. This region is called a "termination shock", since the wind is suddenly terminated there, about both Voyager spacecraft have crossed this boundary, Voyager 2 most recently on August, 31 2007. Voyager 2 crossed this shock at a distance very different than Voyager 1, suggesting that the termination shock is dented - possibly a result of the Milky Way's magnetic field. It was also able to make measurements of the density structure, composition, and magnetic field in this region - discovering that a lot of the energy in the solar wind is transferred to interstellar material ionized by solar wind particles (link). The STEREO spacecraft has also recently discovered high energy neutral particles from this region (link).

Thanks a lot for listening, hope you enjoyed, and any and all feedback is extremely appreciated.