Explanation:

• About 71% of the earth's surface is covered by water which has blue colour. Therefore the earth looks blue when viewed from the space.
• The grains of the Martian soil appear to be coated with iron oxide rust and this planet appears to be red. Also the atmosphere here is filled with dust which gives a strong red colour to this planet. Hence Mars is often called the red planet.
• Saturn has well established rings and Neptune has satellite but no rings.