After the Big Bang, the temperature of the Universe continually dropped as matter organized itself into increasingly complex forms. At the grand scale, the cosmos was initially filled with a homogenous gas consisting mainly of light chemical elements.

Bit by bit, this “universal gas” divided into clouds that began to stick together under the effects of gravity to form giant balls of gas. The first stars were born approximately 400 million years after the Big Bang when the internal temperature of these gaseous balls reached about 10 million degrees and nuclear reactions were initiated. At long last, the Universe ceased to be dark as it began to fill with stars that would eventually combine to form galaxies.

It was in the core of these first stars (and all stars since then) that heavier chemical elements—like carbon, oxygen, silicon and iron—began to form via nuclear reactions. At the end of each star’s life cycle, these “new” chemical elements were released into space where they enriched the clouds of interstellar gas. Gravitational forces eventually regrouped the matter in these clouds to create a new generation of st Read More
After the Big Bang, the temperature of the Universe continually dropped as matter organized itself into increasingly complex forms. At the grand scale, the cosmos was initially filled with a homogenous gas consisting mainly of light chemical elements.

Bit by bit, this “universal gas” divided into clouds that began to stick together under the effects of gravity to form giant balls of gas. The first stars were born approximately 400 million years after the Big Bang when the internal temperature of these gaseous balls reached about 10 million degrees and nuclear reactions were initiated. At long last, the Universe ceased to be dark as it began to fill with stars that would eventually combine to form galaxies.

It was in the core of these first stars (and all stars since then) that heavier chemical elements—like carbon, oxygen, silicon and iron—began to form via nuclear reactions. At the end of each star’s life cycle, these “new” chemical elements were released into space where they enriched the clouds of interstellar gas. Gravitational forces eventually regrouped the matter in these clouds to create a new generation of stars.

The Eagle Nebula, a place where new stars are created.The life cycle of stars is responsible for adding all kinds of chemical elements to the Universe. Under very special conditions, it is even possible for atoms in the space between stars to combine with other atoms and form simple molecules, or even complex molecules like amino acids.

The Sun and the terrestrial, gaseous and icy planets of our solar system.Some stars gain planets after being born. Planets can be terrestrial (that is, made mainly of metal and rock like the Earth and Mars), whereas others are made mostly of gases, like Jupiter and Saturn, or ice, which is probably the case for Pluto.

The Earth is a peculiar case because water can exist in liquid form. Thanks to this simple fact, it was possible for organic molecules (those consisting of carbon atoms) to arrange in complex enough patterns to allow life to form. In this sense, life represents an ultimate stage of development in what is known as the complexity pyramid. The transition from inorganic matter to living matter is one of the most important steps in the arrangement of matter in the Universe.

Although we are fairly certain that life began on Earth at least 3 billion 800 years ago, we still know very little about the conditions that allowed life to originate. One thing we know for sure is that specific organic molecules led to the creation of the first cells and eventually—about 1 billion 200 million years ago—to the creation of the first multicellular organisms.

© 2006 An original idea and a realization of the ASTROLab of Mont-Mégantic National Park

Colour photo of the Eagle Nebula

The Eagle Nebula, a place where new stars are created.

NASA/ESA/STScI/J. Hester and P. Scowen (Arizona State University)

© NASA/ESA/STScI/J. Hester and P. Scowen (Arizona State University)


Compilation of colour photos of the Planets of Our Solar System

The Sun and the terrestrial, gaseous and icy planets of our solar system.

Calvin J. Hamilton

© Calvin J. Hamilton


Diagram showing the Pyramid of Complexity with organisms at the top and sub-atomic particles at the bottom

Pyramid of Complexity.

ASTROLab of Mont-Mégantic National Park

© ASTROLab/Mont-Mégantic National Park


Learning Objectives

The learner will:
  • identify recent contributions, including Canada’s, to the development of space exploration technologies;
  • describe in detail the function of Canadian technologies involved in exploration of space;
  • draw a solar system with all its components;
  • establish the link between atoms and light using different instruments.

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