The faintest stars visible to the naked eye are called:

Who was the first Indian astronaut to travel into space?

Asteroids are

The temperature of the Earth without the greenhouse effect would be: (in $^{\circ} C$)

$A$ total solar eclipse is observed from the Earth. At the same time,an observer on the Moon views the Earth. She is most likely to see ($E$ denotes the Earth):

There are certain types of stars called variable stars which undergo periodic changes in their light output. If such a star quadruples its light output,how much does its magnitude change?