Mercury Report Essay Research Paper Mercury ReportThe

Mercury Report Essay, Research Paper

Mercury Report

The magnificent planet Mercury is the planet I have chosen to research. I this report I have explained all there is to know about Mercury and its aura.

The Romans gave Mercury its name after the fleet-footed messenger of the gods because it seemed to move quicker than any other planet. It is the closest planet to the Sun, and second smallest planet in the solar system. Its diameter is 40% smaller than Earth and 40% larger than the Moon. It is even smaller than Jupiter’s moon Ganymede and Saturn’s moon Titan.

Mercury’s history of formation is similar to that of Earth’s. About 4.5 billion years ago the planets formed. This was a time of intense bombardment for the planets as they scooped up matter and debris left around from the nebula that formed them. Early during this formation, Mercury probably differentiated into a dense metallic core, and a silicate crust. After the intense bombardment period, lava flowed across the surface and covered the older crust. By this time much of the debris had been swept up and Mercury entered a lighter bombardment period. During this period the intercrater plains formed. Then Mercury cooled. Its core contracted which in turn broke the crust and produced the prominent lobate scarps. During the third stage, lava flooded the lowlands and produced the smooth plains. During the fourth stage micrometeorite bombardment created a dusty surface also known as regolith. A few larger meteorites impacted the surface and left bright rayed craters. Other than the occasional collisions of meteorites, Mercury’s surface is no longer active and remains the same as it has for millions of years.

Plains cover the majority of Mercury s surface. Much of it is old and heavily catered, but some of the plains are less heavily cratered. Scientists have classified these plains as intercrater plains and smooth plains. Intercrater plains are less saturated with craters and the craters are less than 15 kilometers in diameter. These plains were probably formed as lava flows buried the older terrain. The smooth plains are younger still with fewer craters. Smooth plains can be found around the Caloris basin. In some areas patches of smooth lava can be seen filling craters.

Like our Moon, Mercury has almost no atmosphere, mostly burned off millions of years ago by the planet’s close proximity to the Sun. What little atmosphere exists is made up of atoms blasted off its surface by the solar wind and has less than a million- billionths the pressure of the Earth’s atmosphere at sea level. It is composed chiefly of argon, neon and helium. Because of Mercury’s extreme surface temperature, these atoms quickly escape into space and are constantly replenished. With no atmosphere to protect the surface, there has been no erosion from wind or water, and meteorites do not burn up due to friction as they do in other planetary atmospheres.

Mercury’s surface very much resembles Earth’s Moon, scarred by thousands of impact craters resulting from collisions with meteors. While there are areas of smooth terrain, there are also cliffs, some soaring up to two miles high, formed by ancient impacts.

Until Mariner 10, little was known about Mercury because of the difficulty in observing it from Earth telescopes. At maximum elongation it is only 28 degrees from the Sun as seen from Earth. Because of this, it can only be viewed during daylight hours or just prior to sunrise or after sunset. When observed at dawn or dusk, Mercury is so low on the horizon that the light must pass through 10 times the amount of Earth’s atmosphere than it would if Mercury was directly overhead.

During the 1880’s, Giovanni Schiaparelli drew a sketch showing faint features on Mercury. He determined that Mercury must be tidally locked to the Sun, just as the Moon is tidally locked to Earth. In 1962, radio astronomers looked at radio emissions from Mercury and determined that the dark side was too warm to be tidally locked. It was expected to be much colder if it always faced away from the Sun. In 1965, Pettengill and Dyce determined Mercury’s period of rotation to be 59 +- 5 days based upon radar observations. Later in 1971, Goldstein refined the rotation period to be 58.65 +- 0.25 days using radar observations. After close observation by the Mariner 10 spacecraft, the period was determined to be 58.646 +- 0.005 days. Mercury s rotational period on its axis is 2/3 of its revolution period around the sun, which is 88 earth days.

Mercury is not tidally locked to the Sun; its rotational period is tidally coupled to its orbital period. Mercury rotates one and half times during each orbit. Because of this 3:2 resonance, a day on is 176 Earth days long as shown by the following diagram, quite a long day for earthlings.

Mercury has no evident satellites or rings for its exists so very close to our scorching sun.

Mercury s mean distance from the sun is 58 million kilometers (about36 million miles). Mercury s diameter is 4875 km (3030 miles). Mercury s volume and mass are about 1/8 that of Earth. Mercury s gravitational pull is .38 times that of Earth.

Scientists believe that during Mercury’s distant past, its period of rotation may have been faster than its speed today. Scientists speculate that its rotation could have been as rapid as 8 hours, but over millions of years it was slowly d