0 like 0 dislike
87 views
in Science by (1.0m points)
Define orbital motion of the earth.

1 Answer

0 like 0 dislike
by (1.0m points)
The earth revolves around the sun, this is called orbital motion of the Earth.

All astronomical objects in the Solar System, including the planets like Earth, orbit around the Solar System's centre of mass. Since the Sun constitutes 99.76% of this mass, the centre of mass is extremely close to the star.

Earth's orbit is the trajectory along which Earth travels around the Sun. The average distance between Earth and the Sun is 149.60 million km (92.96 million mi),[1] and one complete orbit takes 365.256 days (1 sidereal year), during which time Earth has traveled 940 million km (584 million mi).[2] Earth's orbit has an eccentricity of 0.0167.

As seen from Earth, the planet's orbital prograde motion makes the Sun appear to move with respect to other stars at a rate of about 1° (or a Sun or Moon diameter every 12 hours) eastward per solar day.[nb 1] Earth's orbital speed averages about 30 km/s (108,000 km/h; 67,000 mph), which is fast enough to cover the planet's diameter in 7 minutes and the distance to the Moon in 4 hours.[3]

From a vantage point above the north pole of either the Sun or Earth, Earth would appear to revolve in a counterclockwise direction around the Sun. From the same vantage point, both the Earth and the Sun would appear to rotate also in a counterclockwise direction about their respective axes.

History of study

Heliocentrism is the scientific model that first placed the Sun at the center of the Solar System and put the planets, including Earth, in its orbit. Historically, heliocentrism is opposed to geocentrism, which placed the Earth at the center. Aristarchus of Samos already proposed a heliocentric model in the 3rd century BC. In the 16th century, Nicolaus Copernicus' De revolutionibus presented a full discussion of a heliocentric model of the universe[4] in much the same way as Ptolemy had presented his geocentric model in the 2nd century. This "Copernican revolution" resolved the issue of planetary retrograde motion by arguing that such motion was only perceived and apparent. "Although Copernicus's groundbreaking book...had been [printed] over a century earlier, [the Dutch mapmaker] Joan Blaeu was the first mapmaker to incorporate his revolutionary heliocentric theory into a map of the world.

Influence on Earth

Because of Earth's axial tilt (often known as the obliquity of the ecliptic), the inclination of the Sun's trajectory in the sky (as seen by an observer on Earth's surface) varies over the course of the year. For an observer at a northern latitude, when the north pole is tilted toward the Sun the day lasts longer and the Sun appears higher in the sky. This results in warmer average temperatures, as additional solar radiation reaches the surface. When the north pole is tilted away from the Sun, the reverse is true and the weather is generally cooler. North of the Arctic Circle and south of the Antarctic Circle, an extreme case is reached in which there is no daylight at all for part of the year, and continuous daylight during the opposite time of year. This is called polar night and midnight sun. This variation in the weather (because of the direction of the Earth's axial tilt) results in the seasons.

Related questions

0 like 0 dislike
0 answers 27 views
0 like 0 dislike
1 answer 29 views
asked Nov 19, 2018 in Physics by danish (1.0m points)
0 like 0 dislike
1 answer 25 views
0 like 0 dislike
1 answer 422 views
0 like 0 dislike
1 answer 23 views
asked Nov 19, 2018 in Physics by danish (1.0m points)
0 like 0 dislike
1 answer 38 views
asked Nov 19, 2018 in Physics by danish (1.0m points)
0 like 0 dislike
1 answer 43 views
asked Jan 28, 2019 in Science by danish (1.0m points)
0 like 0 dislike
1 answer 55 views
0 like 0 dislike
1 answer 31 views
Welcome to Free Homework Help, where you can ask questions and receive answers from other members of the community. Anybody can ask a question. Anybody can answer. The best answers are voted up and rise to the top. Join them; it only takes a minute: School, College, University, Academy Free Homework Help

19.4k questions

18.3k answers

8.7k comments

3.3k users

Free Hit Counters
...