LIGHTNING

              Lightning is a brilliant electric spark discharge in the atmosphere, occurring within a thundercloud, between clouds, or between a cloud and the ground. This enormous electrical discharge is caused by an imbalance between positive and negative charges. During a storm, colliding particles of rain, ice, or snow increase this imbalance and often negatively charge the lower reaches of storm clouds. Objects on the ground, like steeples, trees, and the Earth itself, become positively charged—creating an imbalance that nature seeks to remedy by passing current between the two charges.
             Some scientists think that Lightening may have played a part in the evolution of living organisms. The immense heat and other energy given off during a stroke have been found to convert elements into compounds that are found in organisms.
             It's true that being inside a building when lightening strikes is your safest bet, but that doesn't mean you shouldn't take some precautions. If a building gets struck the electrical current will most likely travel through the wiring or plumbing before going into the ground. That's why you should stay off of corded phones (cellular and cordless are okay) and away from running water (so no showers or hand- or dish-washing). Don't use stoves, computers, or anything else that's connected to electricity

Lightning

FOG

                           Fog represents the collection of water droplets or ice crystals suspended in the air at or near the Earth’s surface. Fog is basically a low-lying cloud. The only difference between fog and mist is
their density. Fog reduces visibility to less than 1 km while mist reduces visibility to no less than
1 km.
                           Advection fog forms when warm, moist air horizontally moves over a cold surface, which
cools the air to its dew point. Advection fog can form any time, and can be very persistent. It is
common along coastlines where moist air moves from over the water to over the land, or when
an air mass moves over a cold surface (e.g., snow), and the moisture in the air condenses into fog
as the surface cools it. Advection radiation fog forms when warm, moist air moves over a cold
surface, which is cold as a result of radiation cooling. When warm, humid air moves over cold
water, it is called sea fog.

                            The most stable fogs occur when the surface is colder than the air above; that is, in the presence of a temperature inversion. Fogs also can occur when cold air moves over a warm, wet surface

and becomes saturated by the evaporation of moisture from the underlying surface. Convection

currents, however, tend to carry the fog upward as it forms, and it appears to rise as steam or

smoke from the wet surface. This is the explanation of steam fogs that are produced when cold

Arctic air moves over lakes, streams, inlets of the sea, or newly formed openings in the pack ice;

hence, the term Arctic sea smoke.

A Foggy Road

WHY ARE SPECIAL SUITS NEEDED BY ASTRONAUTS?

                        High up in the sky, there is no atmosphere and hence no oxygen. Special suits have provision for supplying oxygen for breathing. They are also necessary to ensure adequate air pressure outside the body.

An Astronaut