Chapter 8: Space Sciences Flashcards
How long ago was the initial “big bang”
15-20 billion years ago
What is a pre-solar nebula?
an interstellar cloud of dust and gasses
what did our solar system look like 5 billion years ago?
a big cloud of dust particles
what held all the interstellar dust particles together
their own gravity
What do scientists believe that the pre-solar nebular was made up of?
99% helium and hydrogen and 1% heavier elements
How did the protosun or protostar develop out of the clouds of gasses?
the gravity would have increased and pulled particles into the centre to form the beginning of a star
What happened in the very centre of the protosun?
the gravity got so strong, and the pressure so high, that hydrogen & helium began fusing (joining)– NUCLEAR FUSION
Did all the dust in the nebula for the sun?
no, some formed swirling rings of gas that eventually cooled and became rocky planets, gas giant planets, dwarf planets, asteroids, meteoroids and comets.
What is the distance from the earth to the sun?
149 600 000 km
What percentage of the total mass of our solar system is taken up by the sun?
98.6% of the mass of the solar system is the sun
What type of star is the sun?
a yellow dwarf star
How many years would it take to get to the sun in a regular airplane traveling 900km/hr?
19 years
How many minutes does it take for light to travel from the sun to earth?
9 minutes
What are the elements that make up the sun
72% hydrogen
26% helium
2% other elements
How come the sun shines?
as it converts hydrogen into helium, in a process called fusion, energy is released
In what way does the energy released from the sun support life on earth?
plants convert the sun’s energy via photosynthesis, and the sun drives our weather and climate
For how many years more will the sun last?
5 billion. It is about 1/2 way used up
When the hydrogen at the sun’s core runs low, what type of star will it evolve into ?
a Red Giant which is an expanded star
Once the sun is at the end of its life cycle, it will cool and become what type of star?
a White Dwarf star
How big is a White Dwarf star?
the size of the earth
Name the four Inner Planets
Mercury, Venus, Earth, Mars
What is the other name for Inner planets?
terrestrial planets
What do these four terrestrial planets have in common?
few or no moons, no ring systems, made of minerals with high melting points which formed crusts and mantles, metals such as iron/nickel which formed their cores. they all have atmospheres, impact craters, and tectonic features such as rift valleys and volcanoes
Who is Mercury named after?
The Roman messenger to the gods
Who is Venus named after?
Venus was the Roman goddess of love and beauty
What is unusual about Venus?
Venus’ atmosphere is very thick and it is hotter on its surface than Mercury
How is Mercury like our moon?
it has lots of impact craters and very little atmosphere
Who is Mars named after?
Mars was the Roman god of war.
Why are we exploring Mars?
some believe it once had water on it which may have supported life
Which is the only planet in our solar system that can support life?
Earth
What is between the orbits of Jupiter and Mars?
an asteroid belt
What is an asteroid?
an asteroid is an irregularly shaped body, sometimes called minor planets. Their orbits around the sun are not easily disturbed.
What is the difference between asteroids and meteoroids?
Asteroids are small, rocky metallic bodies which are caught in orbit with a planet or moon. Meteoroids are the same except they float freely around space.
What is the difference between meteors and meteorites?
When a meteoroid is caught in earth’s orbit it is no longer called that, it is called a meteor. When it reaches earth’s surface it is a meteorite.
What is the Oort Cloud?
It is a cloud approx. one light year away from our solar system that contains hundreds of billions of ice clumps which we call comets.
What is the name of the comet that orbits the sun every 76 years?
Halley’s comet
What is cometary dust?
tiny meteoroids left behind by a comet
What is the name for the place that all the meteors from a meteor shower appear to be coming from?
the radiant
What is a binary system?
two objects in space (most commonly stars but also planets asteroids and even galaxies) that are so close that they orbit each other around a common centre of mass.
What are the names of the twin Mars exploration rovers?
One is called the Spirit and the other The Opportunity.
What year did the Cassini Probe arrive at Saturn?
2004
What was discovered when scientists viewed the pictures taken by the Cassini Probe on Enceladus?
They discovered Enceladus was not only covered in ice but icy geysers as well.
Who described the idea of sailing on light alone as “ships or sails adapted to the heavenly breezes” in a letter to Galileo in 1610?
Johnannes Kepler
What is solar sailing?
The idea of using sunlight to propel a spacecraft.
How would a Solar sailing work?
Giant sails built from lightweight reflective material capture particles called photons. If enough photons push on the sail, they can propel the spacecraft at great speeds.
What is interstellar travel?
Travel between stars.
Why is Solar sailing considered by scientists to be the only reasonable way to make interstellar travel?
Space crafts burn fuel to propel themselves forward through space so they are limited by how much they can carry. With solar sailing the photons from the sun are essentially unlimited and so could carry spacecraft at incredible speeds to very distant destinations.
Name the non profit organization that is working on solar sailing projects.
The Planetary Society
