Space Physics 🌌 Flashcards
What are the main features of our solar system?
The sun
The eight planets
The moons
Asteroids
Comets
What do the planets orbit in our solar system and what type of orbit is it?
The planets orbit the sun in an elliptical orbit.
What is the Sun?
The Sun is the largest object in the solar system and was the first to form.
The Sun’s huge gravitational field keeps many other objects - planets, dwarf planets, asteroids and comets - in orbit around it.
The Sun alone contains 99.8% of the total mass in the solar system.
What are the planets in order from the sun?
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Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
What are the 2 groups of planets?
The rocky planets - the four inner planets (Mercury, Venus, Earth and Mars), which are small, rocky, dense planets, close to the Sun;
The Gaseous planets- the four outer planets (Jupiter, Saturn, Uranus and Neptune), which are large balls of gas, far from the Sun. They are called the gas giants.
The 2 groups of planets are separated by the asteroid belt.
What is a satellite?
It is a body orbiting a planet.
There are 2 different types:
Natural satellites- moons are natural satellites.
Artificial satellites - satellites are artificial satellites.
What are asteroids?
Asteroids are made of metals and rocky material.
There are large numbers of asteroids orbiting the Sun in the asteroid belt between Mars and Jupiter.
They are up to 1000km in diameter.
What is a comet?
Comets are similar to asteroids, but are made of ice, dust and rocky material.
As a comet approaches the Sun, it begins to vaporise, which means that it turns into a gas.
It then produces a distinctive tail.
What are comets?
Comets are made of ice, dust and rocky material. They orbit the sun in an elliptical orbit.
What does gravity provide?
It provides the force needed for the orbital motion of planets, comets, moons and
artificial satellites.
What are the uses of artificial satellites? (X4)
Weather forecasting.
Astronomy.
Communications.
Observation of the Earth.
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How does a star form?
Stars form from massive clouds of dust and hydrogen gas in space.
Gravity pulls the dust and hydrogen gas together.
As the gas falls together, it gets hot.
A star forms when it is hot enough for a nuclear fusion reaction to start.
This releases energy and keeps the star hot.
Smaller masses may also form and be attracted by a larger mass to become planets.
What does light from stars show?
Light from stars, including our Sun, show that:
they are composed mainly of hydrogen
and helium.
their energy is supplied by the fusion of hydrogen into helium.
How are naturally occurring elements formed?
All naturally occurring elements, apart from Hydrogen, are formed by nuclear fusion in stars.
What is the life cycle of a star with similar mass to our Sun?
Protostar - As the mass falls together it gets hot. A star is formed when it is hot enough for the hydrogen nuclei to fuse together to make helium. The fusion process releases energy, which keeps the core of the star hot.
Main sequence - During this stable phase in the life of a star, the outward force of thermal expansion is balanced by the inward force of gravity. The Sun is at this stable phase in its life.
Red giant - When all the hydrogen has been used up in the fusion process, larger nuclei begin to form and the star may expand to become a red giant.
White dwarf - When all the nuclear reactions are over, a small star like the Sun may begin to contract under the pull of gravity. In this instance, the star becomes a white dwarf which fades and changes colour as it cools.
Black dwarf.
What is the lifecycle of a star with greater mass than the Sun?
Protostar
Main sequence
Red supergiant
Supernova - an explosion where the outer layers of the star are ejected. The star will shine for a relatively short amount of time with the brightness of 10 billion suns.
Neutron star/ black hole- after the supernova the remaining core of the star may collapse more, and some become neutron stars, while very massive ones become black holes.
What is the lifecycle of a star with greater mass than the Sun?
Protostar
Main sequence
Red supergiant
Supernova - an explosion where the outer layers of the star are ejected. The star will shine for a relatively short amount of time with the brightness of 10 billion suns.
Neutron star/ black hole- after the supernova the remaining core of the star may collapse more, and some become neutron stars, while very massive ones become black holes.
What is a black hole’s gravitational field like?
There is such a strong gravitational field in a black hole that nothing can escape from it, including electromagnetic radiation such as light.
When did the Big Bang happen?
14 billion years ago, resulting in the formation of the universe.
What happened in the Big Bang?
- Rapid expansion and cooling of the universe.
- The eventual formation of neutrons and protons.
- Further expansion and cooling resulted in nuclei forming.
- Eventually, after further expansion and cooling, the temperature had dropped enough for electrons to combine with neutrons and protons to form atoms of hydrogen.
What is the evidence for the Big Bang?
Red shift:
Light from other galaxies is shifted to the red end of the spectrum, this can be explained by space expanding.
What is CMBR?
Cosmic Microwave Background Radiation is thought to be the heat left over from the original explosion. This is further evidence of the Big Bang and the Big Bang is currently the only model that explains CMBR.
