Topic 1- planet Earth Flashcards
What is light pollution?
Excessive or misdirected artificial light produced by human activity.
How does light pollution affect visibility?
It obscures the darkness of the night sky, making it difficult to observe celestial objects, particularly faint or distant ones.
How can light pollution be reduced?
By using outdoor lighting that is directed downwards instead of upwards or sideways.
What are atmospheric conditions that affect visibility?
Weather factors like cloud cover, dust, and fog.
What is stellar scintillation?
The phenomenon where stars appear to twinkle due to atmospheric turbulence.
What role do humidity and temperature play in visibility?
High humidity and temperature can cause air to become hazy and scatter more light.
How does an observer’s geographical location influence visibility?
The further away from city lights and pollution, the darker the sky and easier it is to observe celestial objects.
How does altitude affect visibility?
Higher altitudes have thinner atmosphere, resulting in less air and other particles to scatter light.
Fill in the blank: Light pollution refers to _______.
[excessive or misdirected artificial light produced by human activity]
True or False: Atmospheric turbulence can improve visibility of celestial objects.
False
What can prevent the observation of celestial bodies?
Cloud cover, dust, fog, and atmospheric turbulence.
List factors that affect visibility of celestial objects.
- Light pollution
- Atmospheric conditions
- Observer’s geographical location
- Altitude of observing location
What are the four main points on the compass?
North, South, East, and West
What is the significance of Cardinal Points?
Essential for navigation and understanding celestial body movements
What does Culmination refer to in celestial terms?
When an object reaches its highest point in the sky
What causes a celestial body to reach its culmination?
The rotation of the Earth
What are the two types of culmination?
Upper Culmination and Lower Culmination
When does culmination occur?
When celestial bodies cross the observer’s meridian
What is a Meridian?
An imaginary line from the North Point, through the zenith, to the South Point
What does the Meridian divide in the sky?
The Eastern and Western halves
What happens when celestial bodies cross the meridian?
They culminate, indicating their highest or lowest point in the sky
What is the Zenith?
The point in the sky directly above the observer
What is the extreme opposite of the Zenith?
The nadir
How is the horizon’s plane related to the nadir and zenith?
It is perpendicular to the line from the nadir to zenith
What does Circumpolarity refer to?
Stars and constellations that never set below the horizon from a given latitude
What factors determine if a star is circumpolar?
Its declination and the observer’s latitude
Which stars are more likely to be circumpolar?
Stars closer to the North or South celestial pole
Give an example of circumpolar stars from the UK.
Polaris, Ursa Major, and Ursa Minor
