The Apollo 11 spacecraft was placed in an elliptical orbit around the moon. The point in a lunar orbit nearest the surface of the moon is called the perilune, and the point fattest from the surface is called the apolune. The Apollo's orbit had a perilune altitude of 110 km and an apolune altitude of 314 km above the moons surface. Find the equation of this ellipse and radius of the moon is 1728 km and the centre of the moon is at one focus

Ceres, the largest asteroid and a dwarf planet, has a semi-major axis of about 2.74 AU. What is Ceres' orbital period in years about the Sun ?

An asteroid closely passes the Earth at a range of 17200mi and a relative speed of 7.8km/s.The diameter is estimated at 30mwith a specific gravity of 3. If this asteroid had impacted Earth, how much energy would have been released? Express this quantity in units of mega-tons (M ton) where a megaton is the energy released by one million metric tons of TNT explosive. A metric ton is 1000kgand the explosive energy density of TNT is 4184J/g.Hint: If the asteroid hits the Earth, its relative velocity becomes zero. Ignore any change in asteroid velocity due to gravitational acceleration or air resistance.

At its closest approach to Earth, Mars is 57.50 million kilometers away. How long (in minutes) would a radio signal sent from a future manned mission to Mars take to travel to Earth? (distance = speed x time) [55]