i need some info on the planet Mars!Urgently!!!?

Answer 1

The fourth planet from the sun is Mars. As it is visible from Earth without the aid of a telescope, Mars has intrigued stargazers since ancient times. Babylonians mentioned Mars in records from about 3,000 years ago, associating the red planet with their god of death. The modern name Mars is that of the ancient Roman god of war; the planet's two moons, Phobos (Fear) and Deimos (Terror), are named after the sons of Ares, the ancient Greek god of war.

Mars passes relatively close to Earth in its orbit. In addition, it generally has no obscuring layer of clouds, unlike Earth's other neighbor, Venus. Thus Mars is a nearly ideal subject for telescopic observation. Over the centuries observers have noted various phenomena on the planet's surface, including a seasonal growing and shrinking of the polar caps and seasonal changes in the appearance of dark markings. The explanation of many early observations had to await the exploratory space missions by the United States and Soviet Union during the 1960s and 1970s.

The fourth planet from the sun, Mars is the outermost of the terrestrial, or Earth-like, planets, which are the dense, rocky worlds closest to the sun. Because Mars has an elliptical orbit, its distance from the sun varies, from about 129 million miles (207 million kilometers) at the closest point in its orbit, or perihelion, to some 155 million miles (249 million kilometers) at its farthest point, or aphelion. The planet completes one revolution around the sun in about 687 Earth days, almost twice the time it takes Earth to complete its orbit of about 365 days. Its distance from Earth varies considerably, from less than 35 million miles (56 million kilometers) to nearly 250 million miles (400 million kilometers). The best time to view Mars from Earth is when it is at its closest to both the sun and Earth so that it appears both bright and large.

With a mean diameter of about 4,219 miles (6,790 kilometers), Mars is the second smallest planet in the solar system, after Mercury. Mars is about half the size of Earth and is much less dense. Its gravity is about a third of Earth's, its surface area about a fourth, and its mass only about a 10th. Like Earth, Mars is roughly spherical, with a slight bulging at its equator and flattening at its poles.

Mars rotates on its axis at roughly the same rate as Earth; a Martian day, called a sol, lasts about 24.7 hours. The red planet is also tilted on its rotational axis at an angle similar to that of Earth. Consequently, like Earth, it is subject to seasonal variations in climate as first one hemisphere and then the other receives more sunlight during the planet's orbit around the sun. Because of its more elliptical orbit, the seasons on Mars are not as even as they are on Earth. The spring and summer in the north, for example, last about 382 days, or more than half the 687-day year. In the south the summer is shorter.

The Martian atmosphere is composed mostly of carbon dioxide and is very thin, exerting about 1/100 the surface pressure that Earth's atmosphere exerts. The thin atmosphere on Mars does not insulate the planet as well as the thicker one does on Earth. The surface of Mars is thus colder than Earth's would be if the two planets were the same distance from the sun. The temperature at the Martian surface varies widely during the course of a day, from about -118 ° F (-83 ° C) just before dawn to about -28 ° F (-33 ° C) in the afternoon. The atmosphere also does not shield the surface from ultraviolet radiation from the sun. This intense radiation bombardment is one reason why scientists believe that no living things currently exist on the surface of Mars.

The Martian surface is dry and dusty. The question of whether liquid water has existed on the surface of Mars is of particular interest to scientists trying to determine if life ever existed on the planet. Liquid water is a requirement for all known forms of life. (But, of course, water does not in itself indicate the presence of living things.) Water currently exists on Mars as ice deposited at the poles, as ice trapped below the surface, and as vapor in the atmosphere. Rivers, lakes, and seas may have been present on Mars in its remote past, when temperatures may have been warmer and the atmospheric pressure higher. Because of the current low temperatures and pressure, it is thought that significant amounts of liquid water have not existed on the surface in modern times, at least not for long periods. Photographs taken in 2000 by the orbiting spacecraft Mars Global Surveyor, however, showed hundreds of gullies that seemed to have formed relatively recently. Some planetary scientists believe that the gullies were carved by flowing water. They theorize that, episodically, small amounts of liquid water have flowed on and just below the surface in geologically recent times and that liquid water may still be present in parts of the planet's subsurface. But this theory has been disputed.

Mars has two small satellites, Phobos and Deimos, which may be captured asteroids. Both are so small that they do not have enough internal gravity to draw them into spherical shapes; instead, they are shaped more or less like potatoes. Phobos is about 17 miles (27 kilometers) long; Deimos is about 9 1/2 miles (15 kilometers) long. Both have rotational periods equal to their orbital periods, so that they always point the same face toward Mars. The surface of Deimos appears smooth because its craters are almost buried in regolith, a layer of fine rubble generated by repeated impacts with other bodies. Phobos is also covered with regolith, but its surface is far more rugged and very heavily cratered.

Phobos is very close to Mars, and its orbit is gradually decaying, so that it is drawing closer to the planet with each orbit. Astronomers estimate that Phobos may fall to the Martian surface sometime in the next 100 million years. Deimos is in a more distant orbit and is gradually moving away from the planet.

Both satellites are very dark and are probably made of a carbonaceous chondrite material. This is a primitive substance that includes many of the first materials to precipitate out of the solar nebula during the creation of the solar system. It is found on many satellites, asteroids, and meteorites.

Answer 2

Mars is the fourth planet from the Sun, and it's smaller than the Earth. It orbits at about 1.5 AU on an elliptical orbit more eccentric than Earth's. Mars has two small moons, Deimos and Phobos, and the planet has been visited by several unmanned missions. There are many craters on the surface, and the polar ice caps may contain water ice. There is a lot more information of many types contained in my reference, which may benefit you considering how general your question was.

Answer 3

Actually there's 8 planets, they kicked out Pluto and called it an exoplanet or a moon that lost is orbit but anyways... Mercury has no astmospere, it's orbital velocity 47.36 km/sec, and its rotation speed is 10.892 kilometers per second. Mercury is full of craters, and very hot. -Venus- orbits every 224.7 Earth days, orbit speed 35.02 kilometers per second. It may have craters but it hard to tell due to its atmosphere. Well check these links