The Universe

• The universe is an enormous space that contains everything that exists, including stars, planets, galaxies, space, energy, and even time.
• It includes our Earth, the Sun, the Moon, all the planets, and countless other celestial objects.
• The universe is very large and is continuously expanding, so galaxies are moving away from each other.

• A galaxy is a huge collection of innumerable stars and their planetary systems, held together by gravity.
• The universe has billions of galaxies; together they make up most of the luminous matter in the universe.
• Galaxies are the basic building blocks of the universe, forming part of what is called the observable universe (about 93 billion light years across).

• The Milky Way is the galaxy in which our solar system is located.
• It contains many stars smaller than the Sun and many stars that are thousands of times bigger than the Sun.
• It also contains clusters of stars, nebulae, clouds of gas, clouds of dust, dead stars, and newly formed stars.
• The Milky Way is part of a small group of nearby galaxies called the Local Group.

The Milky Way

• The Andromeda galaxy is the nearest major galaxy to the Milky Way.
• It is one of the prominent members of the Local Group of galaxies and, like the Milky Way, contains billions of stars.

• Scientists think the universe began in a huge explosion called the Big Bang, about 13.7–15 billion years ago.
• After the Big Bang, matter formed galaxies, stars, and clouds of gas and dust.
• Our solar system likely formed when a gaseous cloud collapsed under its own gravity and formed the Sun and the planets.
• Earth is believed to have formed about 4.5 billion years ago, and life appeared roughly 500 million years after Earth formed.

• The universe is an ever-expanding expanse encompassing all matter, energy, time, and celestial bodies.
• It is primarily structured by billions of galaxies, which are massive, gravitationally bound collections of stars and planetary systems.
• Our solar system is located within the Milky Way, which forms part of the Local Group of galaxies alongside its closest major neighbour, the Andromeda galaxy.
• Scientific consensus suggests the universe originated from a massive explosion known as the Big Bang approximately 13.7 to 15 billion years ago.
• Earth was formed around 4.5 billion years ago from a collapsing gaseous cloud, with the first life emerging roughly 500 million years later.