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Mass
The Earth has a mass of about 5.97 x 10^24 kilograms. The Sun's mass is approximately 1.98 x 10^30 kilograms. While that difference might not seem extraordinary in scientific notation, in plain terms it means that the Sun's mass is about 333,000 times greater than Earth's. That mass holds even the immense, distant gas giants such as Jupiter and Saturn in stable elliptical orbits around their star. The Sun's mass accounts for 99.8 percent of the matter in the solar system.
Weight
Weight and mass are related, but not synonymous to astronomers. An object's weight is a measurement of how strongly gravity affects it. If you weigh 100 pounds on Earth at sea level, you will weigh approximately 17 pounds on the moon, which has about 1/6 Earth's gravitational field; however, your mass remains the same. While the Sun has no solid surface, nor could anyone stand on it if it had one, scientists can calculate what you would weigh on the Sun. If you weigh 100 pounds on Earth at sea level, you would weigh 2,700 pounds on the Sun because its immense mass would exert a stronger gravitational pull on you.
Measuring Gravity
Gravity determines how quickly two objects move toward one another, so scientists measure gravity in terms of acceleration. On Earth, that acceleration is 9.8 meters per second per second, or 9.8 m/s^2. Physicists refer to this force as one g, or normal Earth gravity. You might hear the term as it relates to racing, roller coasters or jets; a 4 g turn means that the driver or rider feels four times the normal force of gravity during the turn. Pilots who regularly perform maneuvers that pull 8 or 9 gs of force must undergo special training to handle this force or they would become unconscious. If Earth's gravity is a single g, then the Sun exerts about 28 gs of gravitational force.
Tidal Forces
Although the moon's proximity gives it a greater visible influence on Earth's oceans in the form of tides, the Sun's overall gravitational influence on the planet is larger than that of the Earth's satellite. However, the Sun's visible influence on tides is less than that of the moon because the difference in gravitational pull from one portion of the Earth to another affects tides more than the total gravitational influence. Because the Sun is so distant, its gravitational pull varies little from one point on Earth to another. Despite its distance, the Sun still exerts about 40 percent of the moon's influence over tides. When the Sun, Earth and moon are in a line with one another -- regardless of whether the Earth or the moon is closer to the Sun -- tides will be exceptionally strong. When two of the bodies form a right angle, weaker neap tides take place.