Meteors and Meteorites (NASA Poster); LG-2005-12-571-HQ -- JPL 400-1253J
Washington DC, Pasadena, CA: National Astronautics and Space Administration and Jet Propulsion Laboratory, 2005. Presumed First Edition, First printing. This is one of a presumed number 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 meteor and seven smaller images of meteorites, a crater, a meteor shower, and meteor/meteorite examination. On the reverse there are three columns of text with the lower half of the right column describing the images on the front side. What’s that flash of light streaking across the sky? We call the objects that creates this brilliant effect by different names, depending on where it is. Meteoroids are space rocks that range in size from dust grains to small asteroids. When meteoroids enter Earth’s atmosphere, or that of another planet, at high speed and burn up, they’re called meteors. When you see lots if meteors, you’re watching a meteor shower. When a meteoroid survives its trip through the atmosphere and hits the ground, it’s called a meteorite. Meteorites typically range between the size of a pebble and a fist. Meteoroids are space rocks that range in size from dust grains to small asteroids. This term only applies when these rocks while they are still in space. Most meteoroids are pieces of other, larger bodies that have been broken or blasted off. Some come from comets, others from asteroids, and some even come from the Moon and other planets. Some meteoroids are rocky, while others are metallic, or combinations of rock and metal. When meteoroids enter Earth’s atmosphere, or that of another planet, at high speed and burn up, they’re called meteors. This is also when we refer to them as “shooting stars.” Sometimes meteors can even appear brighter than Venus – that’s when we call them “fireballs.” Scientists estimate that about 48.5 tons of meteoritic material falls on Earth each day. Several meteors per hour can usually be seen on any clear night. When there are lots more meteors, you’re watching a meteor shower. Some meteor showers occur annually or at regular intervals as the Earth passes through the trail of dusty debris left by a comet (and, in a few cases, asteroids). Meteor showers are usually named after a star or constellation that is close to where the meteors appear to originate in the sky. Perhaps the most famous are the Perseids, which peak around August 12 every year. Every Perseid meteor is a tiny piece of the comet Swift-Tuttle, which swings by the Sun every 135 years. Other notable meteor showers include the Leonids, associated with comet Tempel-Tuttle; the Aquarids and Orionids, linked to comet Halley, and the Taurids, associated with comet Encke. Most of this comet debris is between the size of a grain of sand and a pea and burns up in the atmosphere before reaching the ground. Sometimes, meteor dust is captured by high-altitude aircraft and analyzed in NASA laboratories.
Early Earth experienced many large meteor impacts that caused extensive destruction. While most craters left by ancient impacts on Earth have been erased by erosion and other geologic processes, the Moon’s craters are still largely intact and visible. Today, we know of about 190 impact craters on Earth. A very large asteroid impact 65 million years ago is thought to have contributed to the extinction of about 75% of marine and land animals on Earth at the time, including the dinosaurs. It created the 180-mile-wide Chicxulub Crater on the Yucatan Peninsula. One of the most intact impact craters is the Barringer Meteorite Crater (also called Meteor Crater) in Arizona. It’s about 0.6 miles across and was formed by the impact of a piece of iron-nickel metal approximately 164 feet in diameter. It is only 50,000 years old, and it is so well preserved that it has been used to study impact processes. Geologists have studied the crater since the 1890s, but its status as an impact crater wasn’t confirmed until 1960. Condition: Very good.
Keywords: Meteor, Meteorite, Meteoroid, Impact Crater, Celestial Body, Shooting Star, Asteroids, Chicxulub, Barringer, NASA, Geology, Perseids
[Book #86148]
Price: $32.50