Astronomy 7 Midterm #1 Review

Meteor Impacts and Mass Extinction

1. Impactor (stuff doing the hitting)

asteroid, comets, meteorites

know the definition of: Asteroids, Comets, Meteors

meteor: steak in the sky

meteoroid: a meteorite in the Earth's atmosphere

meteorite: object left on the ground

know where each of them are located in the solar system

e.g. Apollo asteroids are Earth crossing asteroids

know the composition of each type of object

e.g. comets are dirty ice balls

2. Impactee (stuff being hit)

know the factors that govern rate of impacts

size of of the object (surface area)

mass of the object (gravity)

flux of impactors

How are craters destroyed (erosion)

water

sand

other impacts

volcanic cover-up

How do we tell the age of a surface

the more impacts there are, the older

3. Chance of being hit

factors governing our chance of being hit

more often for smaller impactors, less often for bigger ones

know approximately how often

cm sized objects hit

meter sized objects hit

kilometer sized objects hit

4. Mass Extinction Events

• know when the dinosaurs died

• know the major geological eras

• know the result of a major impact event

  • e.g. dust cover blocks sunlight and plants die

The Search for Life in the Universe

1. Life in the Solar System

• Know where we've found conclusive evidence of life

  • okay, trick question, there is only 1 place: Earth

• Know where in the SS we speculate there to be life

  • e.g. Europa, Mars, Titan

  • know the type of life for each planet

2. Factors Governing the Creation of life

• know the general time scale of evolution on Earth

• know the definition of the Goldilock's region

• know around what type of stars we should be looking, and why

  • e.g. not around massive stars, because they have short lifetimes and may be around long enough to develop intelligent life

3. Search for ET

• know why we don't plan to travel to nearby stars

  • e.g. need too much energy

• know the methods of searching for ETs

• know what SETI does and how it searches for ETs

• know why SETI is no longer funded by the government

NASA Missions

1. Mission success rates

• know the approximate success rate of NASA missions

• know some examples of famous failures

2. Hubble Space Telescope

• know the basic function of HST

• know what science HST is capable of

• know why we want to build telescopes in space

  • e.g. to get away from the atmosphere

• understand why it's the focus of so much attention

3. Mars Missions

• understand why Mars missions are so high profile

• know some successful Mars missions and what they do

4. Space Station

• know the scientific goals of the Space Station

• know the "other" goals of the Space Station

• understand why the Space Station is important for future missions