The Earth

Photos of Earth, taken by NASA

The Earth is the third planet of the Sun which is the largest and fifth largest planet of the eight planets in the Solar System. Earth is also the largest planet of the four planets of the Earth Solar System. Earth is sometimes called the world or the Blue Planet.Earth formed about 4.54 billion years ago, and life appeared on its surface in the first billion years. The Earth's biosphere then slowly alters the atmosphere and other basic physical conditions, allowing the breeding of organisms and the formation of the ozone layer, which along with the Earth's magnetic field blocks harmful solar radiation and allows microscopic living creatures to breed safely on land. Physical properties, geological history, and Earth's orbit allow life to survive.The Earth's lithosphere is divided into rigid segments, or tectonic plates, which have been moving throughout the Earth's surface for millions of years. More than 70% of the Earth's surface is covered by water, and the remainder consists of continents and islands that have many lakes and other water sources that contribute to the formation of the hydrosphere. Most of the Earth's poles are covered in ice; solid ice in Antarctic ice sheet and sea ice in polar ice packs. The interior of the Earth remains active, with an inner core composed of solid iron, while the outer core is a fluid that creates a magnetic field, and a relatively thick layer of thickness in the mantle section.The Earth interacts gravitatively with other objects in outer space, especially the Sun and the Moon. When it encircles the Sun in one orbit, the Earth rotates on its axis of 366,26 times, which creates 365.26 solar days or a ciderine year. [Note 7] The Earth's rotation on its axis is tilted 23.4 ° from the orbital plane, seasons on Earth's surface with a tropical one-year period (365.24 solar days). The moon is Earth's only natural satellite, which began to orbit Earth about 4.53 billion years ago. The gravitational interaction between the Moon and the Earth stimulates the tide of the sea, stabilizes the axis of the axis, and gradually slows down the Earth's rotation.Earth is home to millions of living things, including humans. Earth's mineral resources and other biosphere products contribute to the provision of resources to support the global human population. The human-inhabited Earth region is grouped into 200 sovereign states, which interact with each other through diplomacy, travel, trade, and military action.

The slope of the Earth's axis (or obliquitas) and its relation to the rotation axis and the orbital plane

The relative time of the Earth's rotation relative to the Sun - called the day of the Sun - is 86,400 seconds from the average Sun time (86.400,0025 SI sec). Since the current day period of the Sun of the Earth is longer than the period when the 19th century was due to tidal acceleration, every day varies from 0 to 2 SI ms longer.

When the Earth's rotation relative to a fixed star, called the day of stars by the International Earth Rotation and Reference Systems Service (IERS), is 86.164.098903691 seconds from the time of the average Sun (UT1), or 23h 56m 4,098903691s. The time of Earth's rotation relative to the precession or movement of the vernal equinox, called sideris day, is 86.164,09053083288 seconds from the time of the average Sun (UT1) (23h 56m 4.09053083288s) to 1982. Thus, the sideris day is approximately shorter 8 , 4 ms from star day. The average solar day length in seconds SI is calculated by IERS for the period 1623-2005 and 1962-2005.

In addition to meteors in the atmosphere and low-orbiting satellites, the main movement of celestial bodies on Earth is to the west, at a rate of 15 ° / hr = 15 '/ min. For celestial bodies near the equatorial space, its movement is seen in the diameter of the Sun and the Moon every two minutes; from the surface of the Earth, the size of the Sun and the Moon are more or less the same.

Animations featuring the Earth's rotation.

The Earth orbits the Sun at an average distance of about 150 million kilometers per 365.2564 average solar day, or one year of cideris. From Earth, it will be clearly seen the movement of the Sun to the east at a rate of about 1 ° / day, which clarifies the diameter of the Moon or Earth every 12 hours. Because of this movement, the Earth takes an average of 24 hours (or day of the sun) to complete the full rotation on its axis so that the Sun can return to the meridians. The average Earth orbital velocity is 29.8 km / s (107,000 km / h), fast enough to travel the same distance as the planet's diameter, or about 12,742 km in seven minutes, and the distance to the Moon, 384,000 km within 3 , 5 hours.The moon spins with Earth around the line of electricity every 27.32 days. When combined with the Earth-Moon revolution system around the Sun, the synodic Moon period from the new moon to the new moon is 29.53 days. When viewed from the north pole of the sky, the Earth moves, the Moon, and their axis rotations counterclockwise. Whereas if viewed from the viewpoint above the north pole, both the Sun and Earth, the Earth rotates in the opposite direction around the Sun. Earth's orbits and axes are irregular; Earth's axis is tilted approximately 23.4 degrees from the Earth-Sun orbit (ecliptic) orbit, and the Earth-Moon orbiting orbit plane is approximately ± 5.1 degrees from the Earth-Sun orbit plane. Without this slope, the eclipse will appear every two weeks, alternating between a lunar eclipse and a solar eclipse.Sfer hill, or the gravitational sphere of Earth's influence, is about 1.5 Gm or 1,500,000 km in radius. This is the maximum distance when the Earth's gravitational influence is stronger than the Sun and the distant planets. Objects must orbit the Earth within this radius, or they will be affected by the perturbation of the Sun's gravity.The Earth, together with the Solar System, lies in the Milky Way galaxy and orbits about 28,000 light-years from the center of the galaxy. Currently, the Earth is about 20 light-years above the galactic plane of Orion's spiral arms. or more completely can be directly linked https://id.wikipedia.org/wiki/Bumi