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The goal of WMAP is to map out minute differences in the Cosmic Microwave Background ( CMB) radiation in order to help test theories of the nature of the universe. It is the successor to COBE and one of the series of medium-class explorer (MIDEX) satellites.
The Wilkinson Microwave Anisotropy Probe (WMAP) is named after Dr. David Wilkinson, a member of the science team and pioneer in the study of cosmic background radiation. The science goals of the WMAP broadly dictate that the relative CMB temperature be measured accurately over the full sky with high angular resolution and sensitivity. The overriding priority in the design was the need to control systematic errors in the final maps. The specific goal of WMAP is to map the relative CMB temperature over the full sky with an angular resolution of at least 0.3°, a sensitivity of 20 ľK per 0.3° square pixel, with systematic artifacts limited to 5 ľK per pixel.
To achieve these goals, WMAP uses differential microwave radiometers that measure temperature differences between two points on the sky. WMAP observes the sky from an orbit about the L2 Sun-Earth Lagrangian point, 1.5 million km from Earth.
This is the on the line from the Sun to the Earth, but at a larger distance from the Sun than the Earth, where the sum of the (larger) Sun's gravity and the (smaller) Earth's gravity is equal to the centripetal force needed for an object to have the same orbital periodThe orbital period is the time it takes a planet (or another object) to make one full orbit. There are several kinds of orbital periods for objects around the Sun: The sidereal period is the time that it takes the object to make one full orbit around the in its orbit around the Sun as the Earth, with the result that the object will stay in that relative position. Gravity from the Sun is 2% (118 ) less than at the Earth (5.9 ), while the increase of required centripetal force is half of this (59 ). The sum of both effects is balanced by the gravity of the Earth, which is here also 177 .
This vantage point offers an exceptionally stable environment for observing since the observatory can always point away from the Sun, Earth and Moon while maintaining an unobstructed view to deep space. WMAP scans the sky in such a way as to cover ~30% of the sky each day and as the L2 point follows the Earth around the Sun WMAP observes the full sky every six months. To facilitate rejection of foreground signals from our own Galaxy, WMAP uses five separate frequency bands from 22 to 90 GHz.
On February 11February 11 is the 42nd day of the year in the Gregorian Calendar. There are 323 days remaining, 324 in leap years. Events through 1799 660 BC Traditional founding date of Japan by Emperor Jimmu Tenno. 731 Gregory II ends his reign as Pope. 824 Paschal I, 20032003 is a common year starting on Wednesday (link will take you to calendar), and also: The International Year of Freshwater The European Disability Year Summary Perhaps the defining global event of the year 2003 was the Invasion of Iraq launched by the U, the public relationsPublic relations (PR) is the practice of conveying messages to the public through the media on behalf of a client, with the intention of changing the public's actions by influencing their opinions. PR practitioners usually target only certain segments of group from NASA made a press release regarding the age and composition of the universe. This release included the most intricate "baby picture" of the Universe taken so far, while waiting for the launch and results of the Planck Surveyor satellite. According to NASA, this picture "contains such stunning detail that it may be one of the most important scientific results of recent years".