"So do not fear, for I am with you; do not be dismayed, for I am your God. I will strengthen you and help you; I will uphold you with my righteous right hand. All who rage against you will surely be ashamed and disgraced; those who oppose you will be as nothing and perish." (Isaiah 41:10-11)

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Location: Orange, Connecticut, United States

Vote Republican. Life is better in a RED state. / Occupation: Real Estate Broker (Connecticut) / Air War College (04 Jun 1997) Maxwell AFB, AL / Master of Business Administration (1995) at UNH / Master of Public Administration (1995) at UNH / Air Command and Staff College (20 Sep 1988) / Squadron Officer School (17 Mar 1986) / Lieutenant - USNR (retired) / USS America (CV-66) / Bachelor of Arts (1976) in Spanish at SCSU / Emergency Medical Technican (EMT) / Commercial Driver's License (CDL Class AM) / Private Pilot: Airplane Single and Multi-engine Land and Sea (ASMLS) / Thesis (University of New Haven) entitled "U.S. Aerospace Policy in the New Global Economy: The Need for a Definitive National Space Strategy" / NAUI SCUBA diver / Lieutenant Colonel - Civil Air Patrol /

Tuesday, May 01, 2007

Mars and Acidalia

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Mars & Acidalia (4:3) /// Mars has two ice caps, one at each pole. Imaged here is Mars' north polar cap, which exists all year on the Red Planet. The northern hemisphere on Mars gets so cold -- minus 189 degrees Fahrenheit (minus 123 degrees Celsius) -- that carbon dioxide from the atmosphere freezes and adds to the ice cap. This additional "dry-ice" cap disappears as temperatures rise during the martian summer. Credit: NASA /// Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space- based observatory's sharpest views yet of the Red Planet. The telescope's Wide Field and Planetary Camera 2 snapped these images between April 27 and May 6, when Mars was 54 million miles (87 million kilometers) from Earth. From this distance the telescope could see Martian features as small as 12 miles (19 kilometers) wide. The telescope obtained four images, which, together, show the entire planet. Each view depicts the planet as it completes one quarter of its daily rotation. In these views the north polar cap is tilted toward the Earth and is visible prominently at the top of each picture. The images were taken in the middle of the Martian northern summer, when the polar cap had shrunk to its smallest size. During this season the Sun shines continuously on the polar cap. Previous telescopic and spacecraft observations have shown that this summertime "residual" polar cap is composed of water ice, just like Earth's polar caps. These Hubble telescope snapshots reveal that substantial changes in the bright and dark markings on Mars have occurred in the 20 years since the NASA Viking spacecraft missions first mapped the planet. The Martian surface is dynamic and ever changing. Some regions that were dark 20 years ago are now bright red; some areas that were bright red are now dark. Winds move sand and dust from region to region, often in spectacular dust storms. Over long timescales many of the larger bright and dark markings remain stable, but smaller details come and go as they are covered and then uncovered by sand and dust. This image is centered near the location of the Pathfinder landing site. Dark sand dunes that surround the polar cap merge into a large, dark region called Acidalia. This area, as shown by images from the Hubble telescope and other spacecraft, is composed of dark, sand-sized grains of pulverized volcanic rock. Below and to the left of Acidalia are the massive Martian canyon systems of Valles Marineris, some of which form long linear markings that were once thought by some to be canals. Early morning clouds can be seen along the left limb of the planet, and a large cyclonic storm composed of water ice is churning near the polar cap.

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