3.1 Planetary Geology Flashcards
What planets are in the solar system?
- mercury
- venus
- earth
- mars
- jupiter
- saturn
- uranus
- neptune
What are larger distances in space measured in?
Light years
What are light years?
The distance light travels in one year
What is the name of our galaxy?
Milky way
What type of galaxy is the milky way?
Spiral type
How wide is our galaxy in light years?
100,000
What is the name of our nearest star (apart from the sun)?
Alpha Centauri A
How far, in light years, is the most distant known source of light in the universe?
13 billion light years away
By how much did the chief librarian at Alexandra overestimate the circumference of the earth?
789.5 km
How has the length of a year on earth changed over geological time?
It has decreased - used to be over 400 days but now it is 365
What gives information about the interior of the earth?
Seismic waves
How do earthquake waves tell us about the Earth’s interior?
Liquid outer core deflects waves, although solid in the middle
What is a meteorite?
A solid piece of debris from an object that originates from outer space and survives its passage through the earth’s atmosphere and impact with the earth’s surface
What are the 3 main types of meteorite?
- stony
- iron
- stony iron
What are meteorite fall statistics used by planetary scientists for?
To approximate the true flux of meteorites on the Earth
What are meteorite falls?
Meteorites that are collected soon after being witnessed to fall
What is the difference between meteorite falls and finds?
- falls - collected soon after being witnessed to fall
* finds - discovered at a later time
What percentage of falls do stony meteorites account for?
94.4%
What percentage of falls do iron meteorites account for?
4.6%
What percentage of falls do stony iron meteorites account for?
1%
Composition of stony meteorites?
Silicate rocks
Composition of iron meteorites?
Fe and Ni
Composition of stony iron meteorites?
Fe, Ni and Silicates
Why was Iceland used to train Apollo Astronauts?
Moon has similar basaltic rocks that you find in Iceland
What are the darker surfaces visible on the moon?
Large flows of basaltic lava - mare
What are mare?
Large flows of basaltic lava (as they have lava flow patterns attributed to lava tubes)
Why is there no weathering/erosion on the moon?
No atmosphere or liquid water
What are the lighter surfaces that are visible on the moon?
Lunar highlands (terrae)
What are terrae?
Lunar highlands
Why are meteorite craters on the moon preserved for millions of years?
The moon’s rocks don’t get recycled
Why are there no volcanoes or plate tectonics on the moon?
The moon’s crust is not active like the earth’s
How are maps of other planets made?
Use photographs taken by spacecraft and use lander information from the planet’s surface
Where does most of our knowledge of the current geology of mars come from?
Studying landforms and terrain seen in images taken by orbiting spacecraft and from robots exploring surface
What geological features can be found on both Earth and Mars?
- volcanoes
- rift valleys
- dunes
- cross-lamination
- conglomerate
- unconformities
