nearest to the sun
Johannes Kepler.
The question is badly formed.When the Earth is at "perihelion", closest to the Sun in its elliptical orbit, it is moving fastest.When the Earth is at aphelion, farthest from the Sun, it it moving at its slowest.
Neptune orbits the Sun (as do most planets) with an elliptical orbit. When the orbit takes the planet closest to the Sun it is moving faster than when it is furthest from the Sun when on an elliptical orbit.
It's the other way around; the Earth goes around the Sun. The Earth is in an elliptical orbit (but not very elliptical; only about 3% difference from a perfect circle) so the speed of the Earth's movement around the Sun varies a bit. It's moving fastest around January 4, when the Earth is closest to the Sun (called "perihelion"), and moving slowest in early July, when the Earth is farthest away (which we call "aphelion"). But on average, it's moving about 67,000 miles per hour in its orbit.
Red shift. An expanding universe. Although, it may not be that simple. Check out thunderbolts.info for some interesting alternate perspectives.
They are moving in an elliptical orbit
a cold front is the fastest moving front
A skydiver is the fastest moving object in sports.
The safety risks when using a elliptical are the moving parts to the elliptical which can injure fingers while the elliptical is in use. Health risks for the elliptical would be not to use extensively if you are pregnant.
Any object in an elliptical orbit - this would include every planet and natural satellite - is moving fastest when it is closest to the "primary object" around which it orbits; the Sun in the case of the planets, and each planet in the case of a moon. The Earth reaches perihelion, its closest point of approach to the Sun, on January 4 each year, so that's the day at which the Earth is moving fastest in its orbit.
The eyelid is the fastest moving eyelid in the human body
Jacobshavn in southwest Greenland is one of the fastest moving, now at over 12km/year.