• Stars shine with their own light. Some look bright, some dim.
• Long ago, people imagined star patterns as animals, things or story characters. These shapes helped them recognise stars.
• Knowing the stars helped sailors and travellers find directions before the compass and modern technology. It is still a backup method in emergencies.
• Earlier, groups of stars forming patterns were called constellations. Now, the regions of the sky that contain these star groups are called constellations.

Orion is often shown as a hunter, with three stars in the middle as his belt. Some imagine Orion, followed by his dog (Canis Major), fighting a bull (Taurus). Canis Major has Sirius, the brightest star in the night sky.

The Big Dipper and the Little Dipper are two star patterns. The Pole Star (Polaris) is part of the Little Dipper. The Pole Star appears stationary in the North, so it helps us find the North direction in the Northern hemisphere.

In big cities, few stars are seen because of light pollution (too much artificial light at night), smoke and dust. Tall buildings and trees also block the view. The night sky is best seen from open, dark places.

Not all stars can be seen from all places on all nights. For example, the Pole Star cannot be seen from the Southern hemisphere. Sky map apps like Sky Map and Stellarium help you find what is visible from your place.

• The Sun is a star, the one closest to us. It is a very hot ball of gases that gives out a huge amount of energy. It is the main source of energy on Earth.
• It is about 100 times bigger than the Earth in diameter, but looks small because it is very far away.
• Other stars are much farther away, so they look like points, even though some are much bigger than the Sun. In the day, the Sun is so bright that we cannot see other stars.

The Sun, the Earth and many other objects form our Solar System. Moving around the Sun is called revolution.

• A planet is a large, nearly round object that revolves around the Sun. The Earth takes nearly one year to go around the Sun once.
• The Earth also spins (rotates) on its axis; one full rotation takes about 24 hours, which is a day.
• The eight planets, from nearest to farthest from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
• The inner four (Mercury, Venus, Earth, Mars) are small, with solid rocky surfaces.
• Venus shines brightly at dawn and dusk, so it is called the Morning Star or Evening Star, though it is not a star. Mars is the Red Planet (reddish soil). Earth is the Blue Planet (mostly covered with water).
• The outer four (Jupiter, Saturn, Uranus, Neptune) are much bigger and mostly made of gases. They have flat ring-like structures of dust and rock.
• Planets farther from the Sun are usually colder. But an atmosphere can trap heat, so Venus is hotter than Mercury.

After the Sun and the Moon, Venus is the brightest object in the sky. Mercury, Mars, Jupiter and Saturn can also be seen with the naked eye. Stars twinkle a lot; planets do not, which helps us tell them apart.

• Objects that move around planets are called satellites. Moons are natural satellites. Earth has one Moon, Mars has two, and Jupiter, Saturn, Uranus and Neptune have many.
• The Moon takes about 27 days to go around the Earth. It is about 3,84,000 km away and about a quarter of the Earth’s diameter.
• The Moon has almost no atmosphere, water or life. Its surface has bowl-like craters, made by rocks from space hitting it. They stay for a very long time.

• Asteroids are small, rocky, irregular objects. Many revolve around the Sun between Mars and Jupiter: the asteroid belt. They range from about 10 m to 500 km in size.
• Comets are made of dust, gases, rocks and ice, and have long tails. Near the Sun, the frozen material evaporates and forms the tail. They become dim as they move away.
• Halley’s Comet appears every 76 years; it last appeared in 1986. In Sanskrit, a comet is Dhūmaketu.
• Comets were once feared as bad luck, but scientists now know they are just icy-rocky visitors.

On a moonless night far from city lights, you can see a faint band of light across the sky. This is our home galaxy, the Milky Way (Ākāśha Gaṅgā). A galaxy has millions to billions of stars. Our Solar System is part of the Milky Way.

There are many galaxies beyond the Milky Way. We do not yet know if life exists anywhere else. Scientists are searching, mostly on exoplanets (planets around other stars), but have found no evidence so far.

• Find the names of planets in Kannada and the stories about stars in your region, and present them as pictures. (For example: Budha, Shukra, Bhoomi, Kuja/Mangala, Guru, Shani; the Big Dipper is Saptarshi Mandala.)
• Visit a planetarium or science museum, such as the Swami Vivekananda Planetarium at Pilikula, Mangaluru, or the Jawaharlal Nehru Planetarium in Bengaluru.
• Find out how light pollution affects people, animals and the environment, and one thing you can do about it (for example, switch off outdoor lights when not needed).
• Find out why Hanle, Ladakh was chosen for an observatory: high altitude, dry air, very few cloudy nights and very little light pollution.
• Embroider or draw the constellations you have seen on dark cloth or paper.