Twinkle twinkle little star, how I wonder what you are?
Our very first exposure to space, universe, sky was through this beautiful rhyme. We all loved singing this with so much wonder! Now its time to understand more about our universe.
As the sun sets and it begins to get dark, if you look up you can see some amazing wonders that can keep us amused for endless hours, you can see twinkling starts, collection of stars in a particular pattern which we also call a galaxy. Sometimes if you are lucky you can spot some planets that our close to our earth. And, in rare occasions you may spot a shooting star or a falling star; what we call the wish star. There are so many objects that make up our universe, each one fascinating. These objects are called heavenly bodies and their study is called astronomy.
Now, let us understand about the galaxies in the universe, stars and our solar system and the nine planets which are in the solar system. Milky Way is a small galaxy in the universe and, our solar system is a small planetary system in the Milky Way. Our sun is at the centre of the solar system and is a star.
The universe is unimaginably and infinitely big. It is commonly defined as the totality of everything that exists or is known to exist.
The universe consists of galaxies, planets, stars, meteorites, satellites and many other things. Our earth is a part of solar system, which is a part of the Milky Way galaxy. The collection of eight planets and their moons orbit round the sun, together with smaller bodies in the form of asteroids, meteoroids, and comets.
We live on a planet called Earth that is part of our solar system. A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. A galaxy is held together by gravity. Our galaxy, the Milky Way, also has a super massive black hole in the middle.
Stars are the most widely recognized astronomical objects, and represent the most fundamental building blocks of galaxies. The age, distribution, and composition of the stars in a galaxy trace the history, dynamics, and evolution of that galaxy. When you look up at stars in the night sky, you are seeing other stars in the Milky Way. If it's really dark, far away from lights from cities and houses, you can even see the dusty bands of the Milky Way stretch across the sky.
Below is a brief overview of the eight primary planets in our solar system, in order from the inner solar system and outward:
The closest planet to the sun, Mercury is only a bit larger than Earth's moon. Its day side is scorched by the sun and can reach very high temperatures , but on the night side, temperatures drop to hundreds of degrees below freezing.
The second planet from the sun, Venus is terribly hot, even hotter than Mercury. The atmosphere is toxic & the pressure at the surface could crush and kill a person.
The third planet from the sun, Earth is a water world, with two-thirds of the planet covered by ocean. It’s the only world known to harbor life.
The fourth planet from the sun, is a cold, dusty place. The dust, an iron oxide, gives the planet its reddish color.
The fifth planet from the sun, Jupiter is huge and is the most massive planet in our solar system.
The sixth planet from the sun is known most for its rings. The rings are made of ice and rock. Scientists are not yet sure how they formed. The gaseous planet is mostly hydrogen and helium. It has numerous moons.
The seventh planet from the sun, Uranus is an oddball. It's the only giant planet whose equator is nearly at right angles to its orbit - it basically orbits on its side.
The eighth planet from the sun, Neptune is known for strong winds - sometimes faster than the speed of sound.
- Pluto (Dwarf Planet)
Once the ninth planet from the sun, Pluto is unlike other planets in many respects. It is smaller than the Earth's moon.