PLANETS AND SATELLITES
MERCURY
· Mercury is the closest planet to the sun.
· It is extremely hot planet.
· The planet has no water on it.
· Mercury planet has no gases like CO2, N2, H2, and O2 which can act as building blocks of life.
· Mercury planet has not protective blanket like ozone around it to prevent us from harmful radiations.
VENUS
· Venus is the second planet in distance from the sun. this planet is nearest to the earth and is also the brightest planet.
· Venus is known as the “evening star” s well as “morning star”.
· Venus is surrounded by a thick cloud saver, hence known as the “veiled planet’ (‘veil ‘means unclear/ cover).
· Venus is like the earth in size and mass, and hence also known as the “earth’s twin”. It also rotates clockwise like Uranus.
· Venus is the hottest planet (even hotter than mercury) of our solar system, due to its veil of cloud.
· Venus has no water on it. There is no sufficient oxygen on the Venus
THE EARTH.
· Earth is the largest of the inner planets. The earth is 231½˚ tatted on its axis and thus makes 66½˚angle.
· It takes 23 hours 56 minutes and 4.091 seconds to rotate on its axis.
· It takes 365 days, 5 hours and 48 minutes to revolve around the sun.
· Earth is known as the “watery planet” or the “blue planet” due to the presence of huge amount of water on it.
· Earth is the only known planet which provides sustenance or life on it. It has a large quantity of oxygen which supports life.
· The earth has all the essential elements like carbon (in the form of (CO2). Hydrogen (H2), nitrogen 9N2) and oxygen (O2) which act as building blocks for the origin of life.
· The earth is neither neighed too hot nor too cold. It has ‘Goldilocks zone’.
· ‘Goldilocks Zone’ is the habitable zone of solar system where all conditions are available for life to sustain.
· The earth has a lot of water in the form of lakes, rivers and oceans for the growth and survival of life.
· The earth has enough oxygen gas in its atmosphere for the survival of living beings through breathing.
· The earth has a protective blanket of ozone layer high up in its atmosphere to save life from the harmful ultraviolet radiations coming from the sum.
THE MOON
· The moon is the only satellite of the earth.
· It has a diameter of 3475 km. and its circumference is 10864 km. while its orbit is elliptical.
· The maximum distance (apogee) of the moon from the earth is 4, 06, 000 km. and the minimum distance (perigee) is 3,64, 000 km.
· It takes 27 days, 7 hours and 43 minutes to rotate on its axis (this period of about 27½days is called the sidereal month) and approximately the same period of time it takes to revolve around the earth. The moon’s period of revolution with reference to the sun is about 29,53days (29 days, 12 hours, 44 minutes and 2.8 seconds). This period is called a sysnniodic month.
· Only 59 per cent of the total surface of the moon is visible from the earth.
· The bright part of the moon is full of mountains whereas the dark patches are allow lying plains.
· Sea of tranquility’, made of the plain of dust participles, is on the rear side of the moon, which assays remains dark.
· The highest mountain on the moon is Liability Mountain, which is 10, 660 meter high.
· The moon has no atmosphere, no twilight and no sound.
· The temperature during daytime is about 100˚C and during night it drips down to about - 1890˚C.
· The light fro the moon takes 1,3 seconds to reach the earth.
· The size of the moon is one-fourth (1/4th) the size of the earth.
· Gravitational pull of moo is one-sixth (1/6th) that of the earth. Mainly silicon, iron magnesium etc. elements are found on the moon’s surface
· The study of the moon is called “selenologist”.
· Moon is also known as the fossil planet.
MARS
· Iron-rich red soil and pink sky of mars give it the name, “red planet”.
· Problems and demos are two satellites of mars.