Jjmonl 1712.Pmd

alactic Observer John J. McCarthy Observatory G Volume 10, No. 12 December 2017 Holiday Theme Park See page 19 for more information The John J. McCarthy Observatory Galactic Observer New Milford High School Editorial Committee 388 Danbury Road Managing Editor New Milford, CT 06776 Bill Cloutier Phone/Voice: (860) 210-4117 Production & Design Phone/Fax: (860) 354-1595 www.mccarthyobservatory.org Allan Ostergren Website Development JJMO Staff Marc Polansky Technical Support It is through their efforts that the McCarthy Observatory Bob Lambert has established itself as a significant educational and recreational resource within the western Connecticut Dr. Parker Moreland community. Steve Barone Jim Johnstone Colin Campbell Carly KleinStern Dennis Cartolano Bob Lambert Route Mike Chiarella Roger Moore Jeff Chodak Parker Moreland, PhD Bill Cloutier Allan Ostergren Doug Delisle Marc Polansky Cecilia Detrich Joe Privitera Dirk Feather Monty Robson Randy Fender Don Ross Louise Gagnon Gene Schilling John Gebauer Katie Shusdock Elaine Green Paul Woodell Tina Hartzell Amy Ziffer In This Issue "OUT THE WINDOW ON YOUR LEFT"............................... 3 REFERENCES ON DISTANCES ................................................ 18 SINUS IRIDUM ................................................................ 4 INTERNATIONAL SPACE STATION/IRIDIUM SATELLITES ............. 18 EXTRAGALACTIC COSMIC RAYS ........................................ 5 SOLAR ACTIVITY ............................................................... 18 EQUATORIAL ICE ON MARS? ............................................ 6 FRONT PAGE GRAPHIC ...................................................... 18 VISITOR FROM THE OORT CLOUD ..................................... 6 SECOND SATURDAY STARS .................................................. 19 RADIATION STORM ......................................................... 7 DECENBER GRAPHIC CALENDAR ......................................... 20 LUNAR RESOURCES ......................................................... 7 DARK ENERGY SURVEY ................................................... 8 CASSINI'S LEGACY .......................................................... 8 SPACESHIP EARTH AND THE BLUE MARBLE ......................... 9 PURCHASING A TELESCOPE .............................................. 10 DECEMBER HISTORY ...................................................... 12 DECEMBER NIGHTS ....................................................... 14 SUNRISE AND SUNSET ...................................................... 14 ASTRONOMICAL AND HISTORICAL EVENTS ......................... 18 COMMONLY USED TERMS ............................................... 18 EARTH-SUN LAGRANGE POINTS AND THE JAMES WEBB TELESCOPE .................................... 18 2 • Dec 2017 JJMO http://www.mccarthyobservatory.org December Astronomy Calendar and Space Exploration Almanac 100 years after "first light" for the 100-inch telescope, a brush fire threat- ened the historic Mt. Wilson observatory in California (Credits: Observatory: Bill Cloutier, Wildfire: KTLA) http://www.mccarthyobservatory.org JJMO Dec 2017 • 3 “Out the Window on Your Left” T’S BEEN 45 YEARS since ray spectrometer and a cone pen- we left the last footprint on the etrometer to analyze the chemical Idusty lunar surface. Sadly, as a andMare physical Serenitatis properties of the lu- nation founded on exploration and nar regolith. A French-built laser the conquest of new frontiers, we retroreflector was mounted on the appear to have lost our will to lead front of the rover, just below the as a space-faring nation. But, what cone-shaped low gain antenna. if the average citizen had the means Soviet operators lost contact to visit our only natural satellite; with the rover on October 4, 1971 what would they see out the after 11 lunar days/nights (322 window of their spacecraft as they Earth days). Forty years later, on entered orbit around the Moon? November 9, 2011, NASA’s Lunar altitude (20.5 mile or 33 km) pass This column may provide some Reconnaissance Orbiter’s Narrow over Mare Imbrium. The rover was thoughts to ponder when planning Angle Camera captured the rover, parked just 1.4 miles (2.3 kilome- your visit (if only in your imagina- as well as the lander, during a low ters) north of the lander. tion). Sinus Iridum Lunar seas are actually expansive low-lying plains formed by ancient lava flows The Soviet lander, Luna 17, touched down on the lunar surface along the northwestern rim of Mare Luna 17 landed just west of Imbrium (Sea of Showers) on No- Sinus Iridum (Bay of Rainbows). vember 17, 1970. Aboard was the Once the rover was located, its eight wheeled, remote controlled laser retroflector (comprised of rover Lunokhod 1. The 2,000 fourteen corner cubes) was pound rover operated for ten Earth targeted by the laser at the Apache months, driving by lunar day for a Point Observatory. total of 6.5 miles (10.5 km). Dur- Lunar laser ranging (timing the ing the two-week long lunar nights, return of laser pulses from the the rover’s instrumentation was retroflector) provides precise kept warm by a radioisotope-pow- measurements in distance, speed of ered heater. rotation, axial variations and small Lunokhod 1 was equipped with libration effects, improving our Lunokhod 1 rover from orbit an X-ray telescope and cosmic ray understanding of the internal struc- Credit: NASA/GSFC/Arizona detector, a television camera, an X- ture of the Moon. State University 4 • Dec 2017 JJMO http://www.mccarthyobservatory.org Extragalactic Cosmic Rays Cosmic rays shower the Earth charged particles interact with are able to quantify the total en- from many sources, both nearby nitrogen molecules in the ergy of the shower which is and distant, and are comprised of atmosphere, they cause the nitro- equivalent to the total energy of charged particles that can be gen molecules to emit ultravio- the primary cosmic ray. Working accelerated to near light speed let light or fluoresce (the fluores- together, the two detectors (air from violent events, such as the cence detectors only work on and ground) increase the accu- destruction of stars (i.e., super- moonless nights). The detectors racy of the total system. novas). Low energy rays (from solar flares or coronal mass ejec- tions) are effectively stopped by the Earth’s magnetic field. Higher energy cosmic rays (comprised of heavier elements like the nuclei of iron) interact with other nuclei in the Earth’s atmosphere to produce a cascade of atomic particles including electrons, photons and muons which we can detect at the surface. In an article published in the journal Science in September, the Pierre Auger Observatory in Argentina reported the detection of cosmic rays from outside the Milky Way Galaxy. The direction from which the highest energy cosmic ray arrive will allow researchers to pinpoint the Cosmic Ray Surface Detector (above) and Fluorescence Detector source(s), which may reveal the (below) Credit Pierre Auger Observatory triggering event. The observatory is comprised of 1,600 detectors (plastic tanks) distributed over an area comparable to the state of Rhode Island. Each detector contains 3,000 gallons (12,000 liters) of highly purified waste and 3 photomultipliers to record the energy (Cherenkov light) released from the interaction of the cosmic ray with the water. A GPS device provides the timing for the event(s) which when compared to other detectors can be used to determine the trajectory (and possible source) of the ray. The observatory is also equipped with 27 fluorescence detectors in four locations. As http://www.mccarthyobservatory.org JJMO Dec 2017 • 5 Equatorial Ice on Mars? When researchers revisited and reprocessed data collected by NASA’s Mars Odyssey spacecraft between 2002 and 2009, they found unexpectedly high concen- trations of hydrogen in several locations around the Martian equator. A similar signature found at higher latitudes on the Red Planet was subsequently confirmed by NASA’s Phoenix Mars Lander in 2008 to be buried water ice. Credit: NASA/JPL-Caltech/University of Arizona Today, the axial tilt of Mars the poles returned to their present is expressed in the weight percent (25°) is very similar to Earth’s, orientation. of water, assuming that all the but scientists believe that Mars The white outlined areas hydrogen is in the form of water. has experienced much more (above) are part of a formation Certain areas of Medusae Fossae extreme deviations (between 13° called Medusae Fossae that exhibit the highest concentra- and 40°) over periods of 10 to 20 boarders the Martian equator, tions (dark blue), equivalent to million years (the Earth’s large The deposits that comprise the more than 30 weight-percent wa- moon stabilizes its tilt). At formation are thought to date ter. If buried ice exists in the extreme tilts, the Martian polar back to the earliest geological era equatorial region of Mars (or liq- ice cap(s) would sublimate and (Amazonian) and may be associ- uid water in subsurface aquifers), refreeze at lower altitudes. How- ated with the eruptions of the it could provide the raw materials ever, it was not expected that the nearby Tharsis volcanoes. The for future exploration, i.e., a local ice would persist, even if data collected by the Mars source for fuel, drinking water, ra- insulated by blowing dust, once Odyssey’s Neutron Spectrometer diation shielding, and oxygen. Visitor from the Oort Cloud A distant comet, discovered in May by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) in Hawaii,

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