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Flashcards in Our Solar System Deck (29):

What did Galileo discover?

Gallileo (1564-1642) >400yrs ago discovered Jupiter's moons and surface of Saturn.


What are the main bodies in the solar system?

Earth --> Moon
Ceres (Dwarf Planet in Asteroid Belt)
Pluto (Dwarf Planets in Kupier Belt)


What are planets?

Planets are leftover "bits" from the formation of a star in a nebulae.


What is a nebula?

A star forming region e.g orion.


What is special about Europa?

Life elsewhere in our own solar system may be found on Jupiter's moon Europa (which is 1 of c60 moons).

Europa is covered in ice (c20km thick in some places) but believe there is water underneath. Potential to find ice as thin as c1km and land space craft and drill (possibly within our lifetime).


How old is our solar system?

Approximately 4.5 billion years old.


Name 4 key facts about Mercury.

1. Known about for tens of thousands of years (along with the first 5 planets of the solar system).
2. No atmosphere leading to large range of surface temperatures.
3. Quite elliptical orbit.
4. Smaller than the moon.


Name 7 key facts about Venus.

1. Almost circular orbit.
2. Rotates in the opposite direction into what it orbits. Unusual.
3. Very intense atmospheric pressure (93x what it is on Earth).
4. Extremely hot and 96.5% CO2.
5. Day is longer than its year.
6. Known as the "evening star" or "morning star" due to the fact that is rises or sets close to the Sun.
7. Similar size to Earth.


Name 6 key facts about Mars

1. Same day length (almost) as Earth but takes almost 2 years to complete an orbit.
2. Very little atmosphere but temperate ranges from -87 to 20C.
3. Consists of water ice, covered in 1m dry ice (frozen CO2 - freezes at -80C).
4. Has the biggest volcanic in the entire solar system - Olympus Mons.
5. Ridges on Mars caused by water (long since evaporated).
6. Two Moons: Phobos & Deimos (believe they were orginally asteroids caught by Mars's gravity)


Name 3 key facts about Ceres.

1. Discovered in 1800s and was orginally classed as a planet but was reclassed as an asteroid and then a minor planet when other similar bodies were found.
2. The largest object in the asteroid belt.
3. No atmosphere as it is so tiny.


What is an astronomical unit (AU)?

1 AU - astronomical unit = 150m km = avg distance between Sun and the Earth.


What is Bar?

Bar - pressure measurement = 1 bar (1000 millibars) is sea-level. Weather and altitude will affect this.


Name 6 key facts about Asteroid Belt.

1. Leftover pieces from the formation of the Sun.
2. Mainly between Mars and Jupiter, and some that follow Jupiter's orbit.
3. Believe it was a planet that couldn't form due to Jupiter's gravity contiunually pulling it apart.
4. By 2010 just over 500k asteroids discovered.
5. Asteroids can have moons as well e.g. Ida and its moon Dactyl, also known as binary asteroids.
6. Occasionally asteroids hit the Earth e.g. Meteor Crater in Northern Arizona (most famous).


How is the solar system balanced?

All the weight of the solar system is in the Sun.


Name 3 key facts about Jupiter.

1. The largest planet in the solar system.
2. Not big enough to be a star as it is not big enough to have nuclear fussion at its core.
3. The red spot is actually a hurricane that has been going for many many years.


How many moons does Jupiter have?

>60. The four largest are: Io, Europa, Ganymede and Callisto.


How many moons does Mars have?

2 Moons: Phobos & Deimos (believe they were orginally asteroids caught by Mars's gravity)


How many moons does Saturn have?

>60 moons, including:
- Dapnus (80km across within the rings)
- Mimas (has 130km crater but is only 200km across)
- Enceladus (covered in ice and there is water beneath the surface)
- Titan (bit bigger than our Moon and it is covered in clouds due to having enough gravity to hold onto an atmosphere. Has lakes of methane and ethane on its surface).


What is Io?

Io is one of Jupiter's moons. It has over 400 volcanos. The most volcanically active body in the solar system.


What is Europa?

Europa is one of Jupiter's moons. Covered in ice and believe that the ice is moving i.e. floating on a massive ocean of water.

Probably the best place for finding life outside of Earth just technically challenging (possibly a probe will be developed in 20-50 yrs that can drill and study undernearth the surface of ice).


Name 3 key facts about Uranus.

1. Discovered in 1781.
2. Tilted 98deg so "rolls" around the solar system.
3. Has 27 moons including: Miranda - very interesting geology and not sure why.


Name 2 key facts about Neptune.

1. Discovered in 1846 due to mathematical prediction.
2. 13 Moons including: Triton (covered in Nitrogen)


Name 4 key facts about Pluto.

1. Discovered in 1930.
2. Used to be a planet but it is smaller than the moon.
3. Very elliptical and tilted orbit which sometimes comes inside Neptune's orbit.
4. It is now known as a dwarf planet.


Name some dwarf planets.



What is the Kuiper Belt?

Contains 1000+ objects in an asteroid belt beyond Pluto.


What is the Oort Cloud?

The Oort cloud is a spherical 'cloud' of frozen objects at the very edge of our solar system where trillions of comets may circle the Sun at huge distances of up to 20 trillion kilometers (13 trillion miles).


What are comets?

Consists of a nucleus of ice and dust and, when near the sun, a “tail” of gas and dust particles pointing away from the sun.

The Kuiper Belt and Oort Cloud are good suppliers of comets.


What does heliopause mean?

Heliopause = where the sun's influence stops.


What is the difference between asteroid and comet?

While asteroids consist of metals and rocky material, comets are made up of ice, dust, rocky materials and organic compounds.

When comets get closer to the Sun, they lose material with each orbit because some of their ice melts and vaporizes. Asteroids typically remain solid, even when near the Sun.