Newton's "law" of gravity is a mathematical description of the way bodies are observed to attract one another, based on many scientific experiments and observations. The gravitational equation says that the force of gravity is proportional to the product of the two masses (m 1 and m 2), and inversely proportional to the square of the distance (r) between their centers of mass. Mathematically ...
Data from NASA satellite observations provide information about Earth's mean gravity field and inform monthly maps of the time-variable gravity field, both of which are useful tools for scientists as they study the planet's changing climate.
1. Introduction: Review the definition of gravity Drop a ball and explain why it falls downward Explain that the strength of a gravitational pull is determined by the masses of the objects involved and the distance between the objects Hold up a scale model of Earth and a scale model of the Sun. Inquire as to which object would exert a stronger pull
NASA’s twin Gravity Recovery and Climate Experiment (GRACE) satellites can detect groundwater by measuring subtle variations in Earth’s gravity. This image shows the world’s average annual cycle of water storage on land, computed from four years of GRACE gravity data. Colors indicate how much groundwater comes and goes, each year, in various regions; red indicates high levels of annual ...
GRAVITATIONAL PULL See Gravity GRAVITY The force of attraction between two objects which is influenced by the mass of the two objects and the distance between the two objects. GYROSCOPE A heavy wheel or disk mounted so that its axis can turn freely in one or more directions. A spinning gyroscope tends to resist change in the direction of its axis.
To account for gravity and other effects in their equations, the scientists used a model of Earth’s gravitational field, based on data from the GRACE satellite mission. The GRACE mission, like LAGEOS, happens to rely on two identical satellites. However, the similarities between the missions end there.
Gravity waves are a real challenge because they are largely invisible to climate and weather models. The crux of the problem is the way satellites see them. Satellite instruments sweep the atmosphere in either a vertical or horizontal plane, so their measurements are either one- or two-dimensional.
A glacier is a large accumulation of many years of snow, transformed into ice. This solid crystalline material deforms (changes) and moves. Glaciers, also known as “rivers of ice,” actually flow. Gravity is the cause of glacier motion; the ice slowly flows and deforms (changes) in response to gravity. A glacier molds itself to the land and also molds the land as it creeps down the valley ...
A galaxy is a cluster of stars, dust, and gas which is held together by gravity. Galaxies are scattered throughout the universe and they vary greatly in size. A galaxy may be alone or it may be in a large group of galaxies called a "supercluster". Galaxies are classified by scientists according to their shape and appearance. An irregular galaxy has an undefined shape and is full of young stars ...
