Of which planet is Calypso a moon ?

Which is the densest planet ?

Which planet lies closest to the Sun ?

Which planet lies within 10 degrees of Mars at the moment

On which planet does this structure lie ?

Which planet can come closest to Earth ?

Jupiter and Saturn came close in the sky a few weeks ago but did not occult each other. The next mutual occultation of the planets will occur in 2065 when Venus will occult which planet ?

Which planet has the most circular orbit ?

On which planet have beings evolved that can evaluate the integral $\int_0^{\pi}x\ \sin\ x\ dx$   ?