Download File - Physical Science

We are made of star stuff
Carl Sagan famously said, “We are made of star stuff,” and how right he was. While
hydrogen and helium formed shortly after the big bang, the heavier elements—the stuff
that makes up the Earth and its inhabitants—come from stars.
All 92 elements on earth, including those that make up our bodies, originate from the
death of stars. Small stars like our Sun are able to make the smaller atoms by fusion
reactions. Larger stars with heavier cores can make heavier elements up to iron. The rest
of the elements are made by exploding supernovae or the death of largest stars.
Our solar system
Do you know the name of our galaxy?
There are billions of solar systems in our
galaxy and billions of galaxies in the known
universe!
A nebula is an interstellar cloud of dust,
hydrogen, helium and other ionized gases. In
these regions the formations of gas, dust, and
other materials "clump" together to form larger
masses, which attract further matter, and
eventually will become massive enough to form
stars. The remaining materials are then believed
to form planets, and other planetary system
objects.
A supernova is a stellar explosion that is
extremely luminous and causes a burst of radiation
that often briefly outshines an entire galaxy,
before fading from view over several weeks or
months. During this short interval a supernova can
radiate as much energy as the Sun is expected to
emit over its entire life span. The explosion expels
much or all of a star's material at a velocity of up
to 30,000 km/, driving a shock wave into the surrounding interstellar medium. This
shock wave sweeps up an expanding shell of gas and dust called a supernova
remnant.
NUCLEAR FUSION IN STARS: NUCLEOSYNTHESIS
WHY ARE STARS HOT AND BRIGHT?
Nuclear Fusion and Nucleosynthesis
Stars are giant nuclear reactors. In the center of stars, atoms are taken apart by
tremendous atomic collisions that alter the atomic structure and release an
enormous amount of energy. This makes stars hot and bright.
Nuclear fusion is an atomic reaction that fuels stars. In fusion, many nuclei (the
centers of atoms) combine together to make a larger one (which is a different
element). The result of this process is the release of a lot of energy.
Stars are powered by nuclear fusion in their cores, mostly converting hydrogen
into helium.
The production of new elements via nuclear reactions is called nucleosynthesis. A
star's mass determines what other type of nucleosynthesis occurs in its core (or
during explosive changes in its life cycle). Each of us is made from atoms that were
produced in stars and went through a supernova.
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Small stars: The smallest stars only convert hydrogen into helium.
Medium-sized stars (like our Sun): Late in their lives, when the hydrogen
becomes depleted, stars like our Sun can convert helium into oxygen and
carbon.
Massive stars (greater than five times the mass of the Sun): When their
hydrogen becomes depleted, high mass stars convert helium atoms into
carbon and oxygen, followed by the fusion of carbon and oxygen into neon,
sodium, magnesium, sulfur and silicon. Later reactions transform these
elements into calcium, iron, nickel, chromium, copper and others. When these
old, large stars with depleted cores supernova, they create heavy elements
(all the natural elements heavier than iron) and spew them into space,
forming the basis for life.
Nuclear fusion
Visit to the Planetarium
Rio Tinto Alcan Planetarium
4801 Pierre-De Coubertin
Montréal, Quebec H1V 3V4
What you will experience
Exhibition EXO: OUR SEARCH FOR LIFE IN THE UNIVERSE
How did life appear on Earth? Is there life elsewhere? Our insatiable curiosity for life in all
its forms is the starting point of this fascinating exhibition. A playful and interactive quest
through animation, projections and multimedia games! One section of the exhibition also
displays a rich collection of meteorites, some of which hail from the Moon and Mars!
Show CONTINUUM
This immersion show, specially designed by the internationally acclaimed Montréal artistic duo
of Michel Lemieux and Victor Pilon, take visitors on a moving journey through the splendours
and power of space, set to excerpts from the entrancing symphonic music of Philip Glass. From
the infinitely small to the infinitely large, a cosmic poem on the link between humankind and
the Universe.
Show FROM THE EARTH TO THE STARS
Under the clearest starry sky in Montréal, like cosmic explorers, visitors will embark on a
thrilling virtual journey taking them thousands of light years from Earth, all the way to the
stars and beyond! This fascinating immersion in the immensity of the Universe will be
presented live by a skilled astronomy interpreter and will change with the seasons and with
new scientific discoveries. A unique experience every time!