Mrs.Kettner's Science Class
Moon Phases And their Definitions
Waxing:The term used to describe the period of the Moon as it moves from a New Moon to a Full Moon, increasing in visibility with respect to an Earth-bound observer
Waning:The term used to describe the period of the Moon as it moves from a Full Moon to a New Moon, decreasing in visibility with respect to an Earth-bound observer.
Gibbous: There are two Gibbous phases of the Moon, with the first representing the growing moon between the First Quarter and the Full Moon and the second when it describes the Moon growing smaller as it shrinks down from the Full Moon to the Last Quarter. These phases are referred to as the Waxing and Waning Gibbous, respectively.
Crescent:consisting of only a thin crescent slice of the Moon being visible from Earth. This phase of the moon occurs just after the New Moon phase, which is also known as Dark of the Moon. There is also a Crescent Moon phase just prior to the next New Moon as well.
Lunor Cycle: is a period of 19 years (235 lunar months), after which the new and full moons return to the same days of the year. It was the basis of the ancient Greek calendar and is still used for calculating movable feasts such as Easter.
A fun and yummy way to learn how the moon works .
Nicolai Copernicus (1473-1543) radically changed our understanding of astronomy when he proposed that the sun, not Earth, was the center of the solar system.
We now know that Earth orbits the sun elliptically and, at the same time, spins on an axis that is tilted relative to its plane of orbit. This means that different hemispheres are exposed to different amounts of sunlight throughout the year. Because the sun is our source of light, energy and heat, the changing intensity and concentration of its rays give rise to the seasons of winter, spring, summer and fall.
It is not until the ground and oceans absorb enough heat to reach equilibrium with the temperature of the atmosphere that we feel the coldest days of winter or hottest days of summer.
can only occur at Full Moon, and only if the Moon passes through some portion of Earth's shadow. That shadow is actually composed of two cone-shaped components, one nested inside the other. The outer or penumbral shadow is a zone where the Earth blocks part but not all of the Sun's rays from reaching the Moon. In contrast, the inner or umbral shadow is a region where the Earth blocks all direct sunlight from reaching the Moon.
We now know that Earth orbits the sun elliptically and, at the same time, spins on an axis that is tilted relative to its plane of orbit. This means that different hemispheres are exposed to different amounts of sunlight throughout the year
Equinox means the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about September 22 and March 20).
solstice means either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days
Alfred Wegener was born in Berlin in 1880, where his father was a minister who ran an orphanage. From an early age he took an interest in Greenland, and always walked, skated, and hiked as though training for an expedition. He studied in Germany and Austria, receiving his PhD in astronomy. But no sooner did he finish his dissertation than he dropped astronomy to study meteorology, the new science of weather.
In 1910, Wegener noticed the matching coastlines of the Atlantic continents -- they looked on maps like they had once been fit together. He was not the first to notice this, but it was an idea that would never leave his thoughts. In 1911, he published a textbook on the thermodynamics of atmosphere, but at the same time he pursued his studies of the continents. He first spoke on the topic in January of 1912, where he put forth the idea of "continental displacement" or what later was called continental drift. The year 1912 was busy for Wegener: he got married (to the daughter of Germany's leading meteorologist) and he returned to Greenland, making the longest crossing of the ice cap ever made on foot.
convergent boundaries:In plate tectonics, a convergent boundary, also known as a destructive plate boundary(because of subduction), is an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide.
divergent boundaries:in plate tectonics, a divergent boundary ordivergent plate boundary (also known as a constructive boundary or an extensionalboundary) is a linear feature that exists between two tectonic plates that are moving away from each other.
transform boundaries:A transform boundary (or conservative boundary) is where two of the floats - two tectonic plates - side alongside each other. When this happens, the scraping of the two plates causes earthquakes.
subduction zone:Because ocean plates are denser than continental plates, when these two types of plates converge, the ocean plates are subducted beneath the continental plates. Subduction zones and trenches are convergent margins. The collision of plates is often accompanied by earthquakes and volcanoes.
rift zone:A large area of the earth in which plates of the earth's crust are moving away from eachother, forming an extensive system of fractures and faults.
The plate just off the coast of washington is Juan de Fuca.
Beneath the Cascades, a dense oceanic plate plunges beneath the North American Plate; a process known as subduction. As the oceanic slab sinks deep into the Earth's interior beneath the continental plate, high temperatures and pressures allow water molecules locked in the minerals of solid rock to escape. The water vapor rises into the pliable mantle above the subducting plate, causing some of the mantle to melt. This newly formed magma rises toward the Earth's surface to erupt, forming a chain of volcanoes (the Cascade Range) above the subduction zone.
Large convection currents in the aesthenosphere transfer heat to the surface, where plumes of less dense magma break apart the plates at the spreading centers, creating divergent plate boundaries.As the plates move away from the spreading centers, they cool, and the higher density basalt rocks that make up ocean crust get consumed at the ocean trenches/subduction zones. The crust is recycled back into the aesthenosphere.
The scabland was created where the Ice Age floods accelerated across the tilted surface of the Palouse slope, causing massive erosion. Much of the eroded sediment was carried all the way to the Pacific Ocean.