MERCURY
SPEED, SIZE AND APPEARANCE OF MERCURY
Mercury is the second smallest planet after Pluto, and it is the closest to the sun. There was almost nothing known about Mercury until 1974 when the space probe Mariner 10 passed Mercury and sent images of mercury back to earth.Telescopes were unable to detect Mercury as it was always near the sun.
STRUSTURE OF MERCURY
Astronomers think that Mercury contains an iron core that isresponsible fro 70% of her weight and 75% of her diameter. Its mantle is a layer of rock measuring 640 kilometers thick. Traces of hydrogen and helium had been found near the surfaces.
ENVIRONMENT OF MERCURY
In a day in Mercury, its distance freom the sun varies from 70 million kilometers and 56 kilometers. Therefore, the sun's size will vary as the day progresses. At midday on mercury, the temperature reaches up to 420 degrees celcius. At sunset, with no atmosphere to trap the heat, the temperature shoots down to -180 degrees clesius. Anyway, i would like to tell you that a solar day on mersury lasts for about 6 months! This is because Mercury spins very slowly.
MERCURY FACTS