Asteroids Flashcards
asteroid
small (<1000 km) rocky or metal-rich planetary body orbiting the sun
comet
small (<10 km), ice and dust-rich object orbiting sun
meteorite
particle of solid matter that has FALLEN to Earth, the moon, another planet
meteoroid
rock that enters earth’s atmosphere from space, BEFORE IT REACHES EARTH’S SURFACE
meteor
ATMOSPHERIC PHENOMENON created by meteoroid in transit through atmosphere (i.e. the light)
another name for meteor
shooting star or fireball
fireball
exceptionally bright meteor
how much meteorites enter Earth every day? How much survives to the earth’s surface?
- 100 tons/day enter
- 10 g survive
What occurs if a meteoroid retains its cosmic velocity?
creates impact crater on landing
Did the Chelyabinsk event leave an impact crater?
no
NEOs vs PHAs
- NEOs: near earth objects; asteroids or comets; within 50 M km of earth
- PHAs: potentially hazardous asteroids; within 7.5 M km of Earth; > 140 m across
What are the most massive residents of the Main Belt?
largest = Ceres
second largest = Vesta
what was the objective of the Dawn Mission?
observe Ceres and Vesta
TRUE or FALSE: Vesta had rugged topography
TRUE
What are the 2 impact basins on Vesta?
- Rheasilvia basin
- Veneneia Basin
TRUE or FALSE: Vesta does not have a core
FALSE –> Vesta HAS a core
TRUE or FALSE: Ceres is a featureless ball.
FALSE –> rugged topography like Vesta
Describe the layers of Ceres
- icy crust
- soft muddy mantle
What is the purpose of the OSIRIS-REx mission? what is significant about Canada in this mission?
- bring back sample of asteroid Bennu
- Canadian-made Laser Altimeter
Describe Bennu in comparison with Ceres/Vesta.
- more rough with more boulders
- RUBBLE PILE
rubble pile asteroid
asteroid made up of loosely bound pieces of asteroids that were broken up and reassembled
what was the purpose of the Hayabusa2 mission?
get sample of asteroid Ryugu
what kind of asteroid is Ryugu?
rubble pile (like Bennu)
what kind of minerals are found on both Ryugu and Bennu?
carbonaceous chondrites
