In our solar system, the planets are large space objects that orbit around the sun. In the path of a planet’s orbit, there are not many other celestial bodies. However, in the farther reaches of our solar system, there are many objects similar in shape to planets, which also orbit the sun. In the orbit of these objects, are several celestial bodies at the roughly the same distance from the sun. Hence, although these space objects are similar to planets, they are classified separately as dwarf planets, based on the difference in their orbits. There are five officially recognised dwarf planets in our solar system, they are Ceres, Pluto, Haumea, Makemake and Eris.

Just like planet Earth, there are two basic movements that the Moon performs – rotation around itself, and revolution around the Earth. However, the time taken for the moon to rotate on its axis is almost the same as the time taken by it to revolve around the Earth. This is a result of the force of the Earth’s gravity on the moon. Hence, only one side of the moon – called the near side – is visible to Earth. This phenomenon is called ‘Tidal Locking’

The bones in our body make up the skeleton and are alive and growing all the time. Bones are mostly made of collagen which is a protein that provides a soft framework, and calcium phosphate is a mineral that adds strength and hardens the framework. This combination of collagen and calcium makes bone strong and flexible enough to withstand stress. The outer surface of bones is called periosteum. It’s a thin, dense layer that contains blood vessels. Below that is the compact bone. It’s a very smooth but hard bone. Inside the compact bone are the layers of cancellous bones that look like sponge and are very strong. This cancellous bone protects the bone marrow that’s a thick jelly, whose job is to make the blood cells.

Our lips don’t sweat because they don’t contain any sweat glands. Sweat glands are responsible for producing the hydrolipidic film, which keeps skin hydrated. No wonder then that our lips tend to dry out more quickly than other areas of the body.