DID YOU KNOW

.............that earth puts on weight  with ever day that passes ?

The amount of matter that falls onto the earth from outer space is difficult to measure,but it is estimated to be several tonnes a day.This may sound like a lot but compared to mass of earth it is relatively small.Even after a period of 10 billion years , the increase would be less than one-millionth the total mass of the earth.

................constellations  change ?

Stars don't  stand still in space,they  move,but due the speed which they move differ from other stars in speed and direction.However due to huge distances involved these changes remain unnoticed.Only in course of  Ten Thousand years does the distance become obvious. 

....................about dark matter ?

Dark matter does not give off radiation so cannot be detected.Galaxies may be embedded in dark matter whose gravitational pull helps to hold them together, despite gravitational fields of neighboring galaxies.

.................about sunspot activity ?

The sun has 11-year cycles of  sunspot activity due to its changes in magnetic field.The increased surface area  means more solar particles reach earth causing radio interference and aurora.  

.....................about Van Allen Belts ?

The region enclosed by Earth's magnetic field is known as magnetosphere.It captures harmful high energy charged from the sun and traps them into two belts ,named after their discoverer JAMES VAN ALLEN,that encircle the earth above the Equator.