What is the shape of the wavefront on Earth for sunlight?

What is the shape of the wavefront in each of the following cases : light diverging from a point source

A wavefront is

What is the shape of the wave front in each of the following cases : the portion of the wavelength of light from a distant star intercepted by the Earth

What is wavefront ? What is the shape of the wavefront at a point far away from the source of light?

What is the shape of the orbits of planets?

What is the shape of a wavefront emitted by a light source in the form of a narrow slit ?

What is the shape of Fe(CO)_(5) ?

What is the value of 'g' at the centre of Earth ?

What is the geometrical shape of wavefront of light emerging out of a convex lens when a point source is placed at its focus ?