To determine which planet would gravitationally attract the spacecraft the least, we can look at the estimated mass of each planet, as gravitational attraction is directly related to mass. A planet with a lower mass will exert a weaker gravitational pull.
Here are the estimated masses of the planets:
- Venus: 4.87 x 10²⁴ kg
- Mars: 0.642 x 10²⁴ kg
- Jupiter: 1,898.0 x 10²⁴ kg
- Neptune: 102.0 x 10²⁴ kg
Among these, Mars has the smallest estimated mass at 0.642 x 10²⁴ kg. Therefore, the planet that would gravitationally attract the spacecraft the least is Mars.