A particle is launched from the surface of a uniform, stationary spherical planet at an angle to the vertical. The particle travels in the absence of air resistance and eventually falls back onto the planet. Spaceman Fred describes the path of the particle as a parabola using the laws of projectile motion. Spacewoman Kate recalls from Kepler’s laws that every bound orbit around a point mass is an ellipse (or circle), and that the gravitation due to a uniform sphere is identical to that of a point mass. Which of the following best explains the discrepancy?

(A) Because the experiment takes place very close to the surface of the sphere, it is no longer valid to replace the sphere with a point mass.
(B) Because the particle strikes the ground, it is not in orbit of the planet and therefore can follow a nonelliptical path.
(C) Kate disregarded the fact that motions around a point mass may also be parabolas or hyperbolas.
(D) Kepler’s laws only hold in the limit of large orbits.
(E) The path is an ellipse, but is very close to a parabola due to the short length of the flight relative to the distance from the center of the planet.
1. **Understanding the problem**: We need to determine why there is a discrepancy between Fred's description of the particle's path as a parabola and Kate's description of the path as an ellipse, based on Kepler's laws.

2. **Fred's perspective**: Fred uses the laws of projectile motion, which are typically applied in a uniform gravitational field near the Earth's surface. In this context, the path of a projectile is approximated as a parabola.

3. **Kate's perspective**: Kate recalls from Kepler’s laws that any bound orbit around a point mass is an ellipse. This is based on the fact that the gravitational force due to a uniform sphere is identical to that of a point mass located at the center of the sphere.

4. **Reconciling the two perspectives**:
   - Near the surface of the Earth (or any planet), the gravitational field can be approximated as uniform. In this approximation, the path of a projectile is a parabola.
   - However, in reality, the gravitational field is not perfectly uniform, and the true path of the particle is part of an elliptical orbit around the center of the planet.

5. **Analyzing the options**:
   - **Option (A)**: This option suggests that the point mass approximation is invalid near the surface. This is incorrect because the gravitational force of a uniform sphere can still be approximated by a point mass at the center.
   - **Option (B)**: This option suggests that the particle is not in orbit because it strikes the ground. This is misleading because the path is still part of an elliptical orbit, even if it intersects the planet's surface.
   - **Option (C)**: This option suggests that motions around a point mass can also be parabolas or hyperbolas. This is true for unbound orbits, but the problem specifies a bound orbit.
   - **Option (D)**: This option suggests that Kepler’s laws only hold for large orbits. This is incorrect because Kepler’s laws apply to all bound orbits, regardless of size.
   - **Option (E)**: This option suggests that the path is an ellipse but appears very close to a parabola due to the short length of the flight relative to the planet's radius. This is the correct explanation because, near the surface, the elliptical path can be approximated as a parabola.

6. **Conclusion**: The discrepancy arises because, near the surface of the planet, the elliptical path of the particle can be approximated as a parabola due to the short length of the flight relative to the planet's radius.

The final answer is $\boxed{E}$.