General Astronomy Quiz 8 Flashcards
How is Mercury similar to the Moon?
-Heavily cratered
-Airless surface
-Geologically inactive
How is Mercury different from the Moon?
-Moon is a natural satellite that orbits earth
-Mercury is a planet that orbits the Sun
-Mercury is larger, more metallic, and has a magnetic field
What is the dark, smooth area of the Moon called?
Seas (maria in Latin)
Is much of the Moon’s surface covered with craters?
Yes
Do we always see the same side of the Moon?
Yes
How does the Moon rotate?
Around its axis in the same time that it takes to orbit around the Earth–tidally coupled
Does the Moon have an atmosphere?
No
How are the shadows near the terminator of the Moon described?
Sharp and black
What happens to stars behind the Moon’s limb?
They disappear
What is the temperature of the moon during the day?
About 100 degrees Celsius
What is the temperature of the Moon during the night?
About -173 degrees Celsius
What types of terrains are on the Moon?
-Highlands: mountains and craters
-Lowlands: sinus rilles and seas
What are the distinguishing characteristics of impact craters’?
-Shape
-Ejecta
-Rays
-Secondary craters that form around impact craters
Describe the size of lunar impact craters.
Range from tiny pits formed by micrometeorites to giant multiringed basins
When did most of the Moon’s craters form?
When the Solar System was young (about 4.56 billion years ago)
What does the age of the Moon rocks provide evidence of?
A late heavy bombardment that was 4.1 to 3.8 billion years ago
How common are cratering events in the inner Solar System?
A million times less common than they were when the Solar System was young
What is the goal of science?
To explain details with a unifying hypothesis, not just memorize them
What was the difficult part of the Apollo missions?
Landing and returning to Earth
What was the solution for the issues with the Apollo Mission?
To design two vehicles
-Command module for the round trip
-Landing module to land on the moon
When did the first successful human-piloted lunar landing occur?
July 20, 1969
Are lunar rocks igneous?
Yes
Does the moon have sedimentary rocks?
No
Is there water on the Moon?
Yes, but only a little and mainly in the form of ice
What is the lunar maria composed of?
Dark, dense basalts
Some basalts are…
Vesicular
What type of rocks do highlands contain?
Anathorsite rocks
What are highlands and lowlands covered in?
Regolith
Is the Moon small?
Yes
What are some characteristics of the Moon?
– Low mass caused rapid cooling off
– Small escape velocity
– Lack of atmosphere could not protect surface
from meteorite impacts
In what state is it presumed the Moon formed in?
The molten state
What is the molten state?
When heavy rocks sink to bottom; lighter rocks are at the surface
The Moon does not have a…
Magnetic field
What is the large impact hypothesis?
When a large planetismal smashed into the proto-Earth, ejecting a disk of debris that formed into the Moon
Is Mercury tidally locked with the Sun?
Yes
How often does Mercury rotate?
Three times for every two revolutions around the Sun
What is orbit resonance?
When orbiting bodies exert regular, gravitational influence on each other
What are fixed stars?
Stars that do not appear to move relative to one another
Does Mercury have a natural satellite?
No
What is a natural satellite?
An astronomical body that orbits a planet, dwarf planet, or small Solar System body
Mercury is more than ___ denser than the Moon
60%
Do we know why Mercury contains so much sulfur despite being so close to the Sun?
No
How strong is Mercury’s magnetic field?
1.1 as strong as Earth’s
What is Mercury’s mystery?
Contains a large core of dense liquid metals, mostly iron
What did the bombardment that occurred on Mercury remove?
Lighter rocks from the surface
What happened to Mercury’s cooling interior and what broke?
-Cooling interior contracted
-Crust broke to form lobate scarps (lava flooding ended)
What caused Mercury’s slow surface evolution?
Micrometeorites
