Earth's Moon (NASA Poster); LG-2005-12-566-HQ -- JPL 400-1253G
Washington DC, Pasadena, CA: National Astronautics and Space Administration, Jet Propulsion Laboratory, 2005. Presumed First Edition, First printing, This is one of multiple originals issued. Poster. The format is approximately 8 inches by 10 inches. This is a single sheet, with printing/imagery on both sides, in a plastic sleeve. On the front side is a large color photograph of Earth's moon on the left side and a series of smaller photographs/images on the right, including Astronauts on the Moon, footprint on the moon, Craters, and a view of Earth from the Moon. The text on the reverse side has general descriptive narrative, Fast Facts, Significant Dates, and information about the images on the front. The Earth and the Moon form the Earth-Moon satellite system with a shared center of mass, or barycenter. This barycenter is 1,100 miles (about a quarter of Earth's radius) beneath the Earth's surface. The Moon's orbit is slightly elliptical, with an orbital eccentricity of 0.055. The semi-major axis of the geocentric lunar orbit, called the lunar distance, is approximately 250,000 miles or 1.28 light-seconds, comparable to going around Earth 9.5 times. The Moon makes a complete orbit around Earth with respect to the fixed stars, its sidereal period, about once every 27.3 days. Due to tidal locking, the Moon has a 1:1 spin–orbit resonance. This rotation–orbit ratio makes the Moon's orbital periods around Earth equal to its corresponding rotation periods. This is the reason for only one side of the Moon, its so-called near side, being visible from Earth. The plane of the Moon's orbit gradually rotates once every 18.61 years, which affects other aspects of lunar motion. These follow-on effects are mathematically described by Cassini's laws. The Moon is Earth's only natural satellite. It orbits at an average distance of 238,900 miles, about 30 times the diameter of Earth. Tidal forces between Earth and the Moon have over time synchronized the Moon's orbital period (lunar month) with its rotation period (lunar day) at 29.5 Earth days, causing the same side of the Moon to always face Earth. The Moon's gravitational pull – and to a lesser extent, the Sun's – are the main drivers of Earth's tides. In geophysical terms the Moon is a planetary-mass object or satellite planet. Its mass is 1.2% that of the Earth, and its diameter is 2,159 miles, roughly one-quarter of Earth's (about as wide as Australia.) Within the Solar System, it is the largest and most massive satellite in relation to its parent planet, the fifth largest and most massive moon overall, and larger and more massive than all known dwarf planets. Its surface gravity is about one sixth of Earth's, about half of that of Mars, and the second highest among all Solar System moons, after Jupiter's moon Io. The body of the Moon is differentiated and terrestrial, with no significant hydrosphere, atmosphere, or magnetic field. It formed 4.51 billion years ago, not long after Earth's formation, out of the debris from a giant impact between Earth and a hypothesized Mars-sized body called Theia. The lunar surface is covered in lunar dust and marked by mountains, impact craters, their ejecta, ray-like streaks and, mostly on the near side of the Moon, by dark maria ("seas"), which are plains of cooled magma. These maria were formed when molten lava flowed into ancient impact basins. The Moon is, except when passing through Earth's shadow during a lunar eclipse, always illuminated by the Sun, but from Earth the visible illumination shifts during its orbit, producing the lunar phases. The Moon is the brightest celestial object in Earth's night sky. This is mainly due to its large angular diameter, while the reflectance of the lunar surface is comparable to that of asphalt. The apparent size is nearly the same as that of the Sun, allowing it to cover the Sun completely during a total solar eclipse. From Earth about 59% of the lunar surface is visible over time due to cyclical shifts in perspective (libration), making parts of the far side of the Moon visible. The Moon has been an important source of inspiration and knowledge for humans, having been crucial to cosmography, mythology, religion, art, time keeping, natural science, and spaceflight. In 1959 the first human-made objects to leave Earth and reach another body arrived at the Moon, with the flyby of the Soviet Union's Luna 1 and the intentional impact of Luna 2. In 1966, the Moon became the first extraterrestrial body where soft landings and orbital insertions were achieved. On July 20, 1969, humans for the first time landed on the Moon and any extraterrestrial body, at Mare Tranquillitatis with the lander Eagle of the United States' Apollo 11 mission. Five more crews were sent between then and 1972, each with two men landing on the surface. The longest stay was 75 hours by the Apollo 17 crew. Since then, exploration of the Moon has continued robotically, and crewed missions are being planned to return beginning in the late 2020s. Condition: Very good.
Keywords: NASA, Space, Moon, Earth, Lunar, Cassini, Crater, Neil Armstrong, Apollo 11, Spacecraft, Space Exploration, Soft Landing, Spin-orbit Resonance
[Book #86149]
Price: $32.50