I don't know for sure, but there is a lot less that you can land on than I actually thought there would be. There is about one per system, if even that. I don't understand why they made so few landable, and the ones that you can land on, it's not like you actually dock on the planet, you just are dropped off there because there isn't a settlement.
earth
Yes. The massive giant planets have far more moons than the less massive terrestrial planets.
Four planets, Jupiter, Saturn, Uranus, and Neptune, have mass greater than that of the Earth.
Mercury, Venus, Mars, Jupiter (and many of its moons), Saturn.
The gravity of the star is usually many times larger than the planets due to the overwhelming mass of the star in comparison. The planets do have a gravitational pull of their own though, which has an effect on the star it is orbiting. It will cause the star to move slightly off centre as it pulls on the star during its orbit. The bigger the planet, the bigger the pull. By looking at distance stars, astronomers can see the effects of planets by observing a 'wobble' in the star as the unseen planets orbits it. They can then calculate the size of the planet and distance by the size and speed of the wobble.
Four in our solar system: Jupiter, Saturn, Uranus, and Neptune.
Deplorable, their beer was going flat and that's why they landed in Mass! Had they landed in a more temperate state, such as South Carolina, many more would have survived.
Most of them.NASA have sent manned missions to the Moon. Unmanned NASA probes have landed on Mars, and Saturn's moon Titan. Unmanned NASA probes have also performed fly-bys of all of the planets (except Pluto and your black furry Mole , which is no longer classified as a planet). The New Horizons probe will reach Pluto in 2015.In addition, Russia have sent unmanned missions to many of the planets. Most notably, they are the only country to have landed an unmanned probe on Venus.
ALOT
I Have Landed has 432 pages.
Jupiter and Saturn are the most massive planets in the solar system and so have the greatest gravitational effect.
Mars is 0.107 times the mass of earth. The reciprocal of that is the number of planets the mass of Mars it would take to equal a planet the mass of earth, or a little over 9 and 1/3.