Satellite Motion 3

If you look up at night and see this string of lights is moving across the sky, what are you seeing ?

• UFO parade

• Recently launched Starlink satellites

• Weather balloons

• GPS satellites

What is the primary job of Starlink satellites ?

• Provide Internet access for people around the world

• Spy on other countries who are not friendly

• Broadcast all the television stations to world

• Monitor the weather in places where meteorologists don't live

Which of these can you sometimes see just by watching the night sky ?

• GPS satellites

• Low Earth orbit satellites

• Geostationary satellites

Answer explanation

GPS satellites and geostationary satellites orbit too far away to see with the naked eye and geostationary satellites wouldn't appear to be moving.

Which of these satellites takes the least time to make one orbit?

• Satellites in low Earth orbit

• GPS satellites

• Geostationary satellites

• Earth's moon

Answer explanation

Satellites in low Earth orbit take about 1.5 hours to complete one orbit.

GPS satellites take about 12 hours while geostationary satellites take 24 hours. Earth's moon, being the farthest away of these four, takes over 27 days to complete one orbit.

What is the best time of year to view satellites (in the northern hemisphere)?

• May through August

• January - March

• September - December

• All months are equal

Answer explanation

This is because Earth's shadow this time of year has less effect on viewing.

What time in a day is the best time to view satellites?

• Any time during the day

• The first and last two hours of darkness

• The first and last two hours of daylight

• In the middle of the night.

Answer explanation

That is when the satellites are not in Earth's shadow which allows them to reflect sunlight and be seen. They can't be seen in the daytime just like stars can't be seen during the day.

What direction will you NEVER see a satellite coming FROM?

• North or South

• East

• West

• Northwest or southwest

Answer explanation

Satellites never travel from east to west. This would work against Earth's rotation and require a more powerful rocket and a much higher expense.

They are often launched so that they go at least somewhat west to east or north/south.

All GPS satellites have a ____ and a ____. (Two answers needed)

• Super accurate atomic clock

• Nuclear reactor

• Radio transmitter

• Laser weapon

By itself, GPS can't provide accuracy any better than ____.

• 3 feet

• 2 inches

• 10 feet

• 1 foot

Ground based systems can increase the accuracy of GPS systems.

• True

• False

Answer explanation

WAAS is one system that most receivers also make use of which will improve accuracy to about 3 feet. Other systems can get accuracy down to an inch.