On 7th December, 1972, the crew members of Apollo 17 spacecraft took a photograph of the Earth. This photograph, known as The Blue Marble, gives a clear idea as to why we know Earth as the Blue Planet. The earth’s surface contains more than 70 per cent water distributed in the oceans. Water molecules in…
The peregrine falcon, earlier known as the ‘duck hawk’, is the fastest flying bird on the planet. With an average diving speed of 320 km/h during its hunting stoop, the bird becomes the fastest living creature in the world. The peregrine falcon holds the record for the maximum airspeed of 389 km/h. Barring extreme polar regions, high…
Lightning bolts are electric discharges that originate in the clouds during a storm and travel to the earth’s surface. About 100 lightning bolts strike the earth every second. One bolt can contain up to one billion volts of electricity.
Only 3 per cent of earth’s water is fresh, the rest 97 per cent is salt water. Of that 3 per cent, over 2 per cent is frozen in ice sheets and glaciers. It means less than 1 per cent fresh water is found in lakes, rivers and underground. Water, indeed is a scarce resource.
The earth is divided into three layers: the upper crust, the middle mantle and the innermost core. The upper crust is made of solid plates, called tectonic plates. Some plates are under the ocean too. The mantle is semi solid and the tectonic plates slide over the mantle, causing an earthquake. Every year over one…
A raindrop falls on the earth with varying speeds depending on its size and weight. The gravity acts on the falling raindrop and the drop picks up speed. But due to air resistance, which is generally proportional to the velocity, the raindrops attain a terminal speed. A larger raindrop would fall much faster at 9…
