Earth | |
---|---|
Diameter (km) | 12.756,32 |
Distance to sun (km) | 149,600,000 |
Equator (km) | 40,075 |
C° | -89/58 |
Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating and other evidence, Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects in space, especially the Sun and the Moon, which is Earth's only natural satellite. Earth orbits around the Sun in 365.256 solar days, a period known as an Earth sidereal year. During this time, Earth rotates about its axis 366.256 times, that is, a sidereal year has 366.256 sidereal days.Earth's axis of rotation is tilted with respect to its orbital plane, producing seasons on Earth. The gravitational interaction between Earth and the Moon causes tides, stabilizes Earth's orientation on its axis, and gradually slows its rotation. Earth is the densest planet in the Solar System and the largest and most massive of the four rocky planets.
Earth's outer layer (lithosphere) is divided into several rigid tectonic plates that migrate across the surface over many millions of years. About 29% of Earth's surface is land consisting of continents and islands. The remaining 71% is covered with water, mostly by oceans but also lakes, rivers and other fresh water, which all together constitute the hydrosphere.
Mars | |
---|---|
Diameter (km) | 6,792 |
Distance to sun (km) | 227,940,000 |
Equator (km) | 21,297 |
C° | –133 |
<p>Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury. </p>In English, Mars conveys the title of the god of war and is often known as the'Red Planet'. The latter describes the effect of the iron oxide prevalent on Mars' surface, which gives it a reddish look distinctive one of the astronomical bodies visible to the naked eye. Mars is a terrestrial planet with a thin atmosphere, with surface features reminiscent of the impact craters of the Moon and the valleys, deserts and polar ice caps of Earth.
Since the period in addition to the tilt of the axis relative to the ecliptic plane are similar the days and seasons are similar to those of Earth. Mars is the site of Olympus Mons, the largest volcano and highest known mountain and of Valles Marineris, among the largest canyons in the Solar System. The Borealis basin in the northern hemisphere covers 40% of the planet and may be a giant impact attribute. Mars has two moons, Phobos and Deimos, which are irregularly shaped and small. These can be captured asteroids, similar to 5261 Eureka, a Mars trojan.Mars was explored by unmanned spacecraft. Mariner 4, launched by NASA on November 28, 1964, was the first spacecraft to go to Mars, making its closest approach to the planet on July 15, 1965. Mariner 4 noticed that the weak Martian radiation belt, measured at about 0.1percent that of Earth and captured the first images of another planet from deep space. On July 20, 1976, Viking 1 performed the first successful landing. A soft landing was attained by the Soviet Mars 3 spacecraft in December 1971 but contact was lost with its lander seconds after touchdown. On July 4, 1997, the Mars Pathfinder spacecraft landed on Mars and on July 5 released its rover, Sojourner to operate on Mars.
<p>Mars is the fourth planet from the Sun and the second-smallest planet in the Solar...
Mercury is the first planet from the Sun and the smallest in the Solar System. In English, it is...
Pluto (minor planet designation: 134340 Pluto) is an icy dwarf planet in the Kuiper belt, a ring...
<p>Saturn is the sixth planet from the Sun and the second-largest in the Solar System,...