Earth is the third planet in our solar system and the only astronomical object known to harbor life. Earth is believed to have formed over 4.5 billion years ago and the thesis is backed by radiometric dating and other sources of evidence. Earth's gravity interacts with other objects and celestial bodies in space such as the Sun and the Moon, which is Earth's only natural satellite. Earth orbits around the Sun in 365.256 days which marks as one sidereal year of Earth. Earth's axis of rotation is tilted with respect to its orbital plane which causes the seasons on Earth. The gravitational interaction between Earth and the Moon causes tides, stabilizes the orientation of the Earth on its axis and gradually slows its rotation. Earth is the densest planet out of all the planets in our Solar System. It is also the largest and most massive of the four rocky planets. The lithosphere of the Earth is divided into several rigid tectonic plates that migrate across the surface over many millions of years. About 71% of Earth's surface is covered with water while the remaining 29% is land consisting of continents and islands that together contain many lakes, rivers and other sources of water that contribute to the hydrosphere. The majority of polar regions of Earth are covered in ice, such as the Antarctic ice sheet and the sea ice of the Arctic ice pack. The interior of the Earth remains active with a solid iron inner core, a liquid outer core that generates the Earth's magnetic field and a convecting mantle that controls plate tectonics.
In this sub category you can download free PNG images: Earth Nature. In this category "Earth" we have 20 free PNG images with transparent background.