|Note to remember|
|Asteroids are small rocky planetoids, while comets are formed of grozen gases held together by rocky and metallic material.|
|Comets show a perceptible glowing tails, while asteroids do not.|
|Asteroids are found mostly between the orbits of Mars and Jupiter, while comets are found mostly in Kuiper belt region and Oort cloud region.|
|Satellites used for telecommunication relay are kept in a geostationary orbit.
A satellite is said to be in such an orbit when:
1) the orbit is geosynchronous.
2) the orbit is circular.
3) the orbit lies in the plane of the Earth's equator.
4) the orbit is at an altitude of 36000 km or 22000 miles.
|The 23.5 degree inclination of the Earth's rotation axis with respect to the plane of the ecliptic is the reason for 'seasons' on the surface of the Earth.|
|A person stood alone in a desert on a dark night and wanted to reach his village, which was situated 5 km East of the point where he was standing. He had no instrument to find the direction, but he located the pole-star. The most convenient way now to reach his village is to walk in the direction keeping the pole-star to his left.|
|Deltaic regions of Mahanadi, Godavari and Krishna areas is conducive for well irrigation.|
|When there is noon at IST meridian people in another place of the Earth are taking their 6 O'clock morning tea. The longitude of the place is 90 degree west.|
|South Pacific island nation Samoa, positioned to the East of the International Date Line, on May 2011 decided to forego a day and shift the time zone on its west. The reason for this shifting is to facilitate trade with Australia and New Zealand.|
|Stalacites hang as icicles of different diameters and stalagmites rise to from the floor of the caves.|
|The greatest reasonal contrast of insolation on the Earth is in Temperate latitudinal zones.|
|The correct sequence of the given planets in increasing order of their size (diameter):
Mercury < Mars < Venus < Earth < Uranus
|Nearly 30% of the solar radiations return back to the space without contributing anything to the Earth's surface temperature. This amount of radiations is known as Earth's albedo.|
|We always see the same face of moon because it takes equal time for the revolution around the Earth and rotation on its own axis.|
|The 'Blue Moon' phenomenon occurs when two full moons occur in the same month.|
|The inexhaustible source of energy of the stars is due to conversion of hydrogen to helium.|
|The International Date Line is largely based on the 180 degree meridian.|