STEREO orbits

 

Activity Part 1

 

We’re trying to find the distances of each spacecraft from Sun.

 

We can do this using Kepler’s Law and the information we’ve been given about the periods of orbit.

 

 

 

In 1 year the Earth goes around the Sun once, that’s 360°.

STEREO A will drift ahead by 22° per year, which means that it will go round 360° + 22° per year.

STEREO B drifts behind by 22° per year, which means that it will go round 360° - 22° per year.

 

 

 

From this we can find the time periods, in years, for each spacecraft to complete 1 orbit.

 

And from these we can use Kepler’s Law to find the orbital distances in AU’s.

STEREO A’s orbital distance in AU should be less that 1, i.e. it will be closer to the Sun than the Earth.

STEREO B’s orbit in AU should be greater than 1, i.e. it will be further from the Sun than the Earth.