Apsis
TrES-4 is actually a star. It appears to have at least one planet. I don't think we have the technology yet to detect any moons around the planet.
All 8 planets, including dwarf planet Pluto, orbit the Sun. As their distance from the Sun increases, the time it takes for the planet to complete one revolution around the Sun increases as well. In order from shortest orbital period to longest orbital period:MercuryVenusEarthMarsJupiterSaturnUranusNeptune
At least two very big things: the Kyper Belt beyond the orbit of Neptune, and farther out, the Oort Cloud.
The one closest to the star, in the case of our solar system, that is Mercury.
Apsis
If you are asking what planet has the least days in a full trip around the sun, it would be the planet Mercury, the moon has the least days in a trip with 29, however it is not counted as a planet.
Saturn is the least dense of the gas giants, even out of all of the planets in our solar system. Its average density is around 0.7 g/cc (less than water).
Yes, at least 13. They are not very bright though.
I Say Mercury.
The planet with the least mass and smallest is Mercury. The planet with the lowest density is Saturn
Saturn is the least dense planet in our solar system.
TrES-4 is actually a star. It appears to have at least one planet. I don't think we have the technology yet to detect any moons around the planet.
Hawaii, because it is closest to the equator therefore covering more distance in the same amount of time, so its faster!
Mercury is the least massive of all the planets. The least massive planet is Mercury (0.055 Earths). However, the planet with the weakest gravity is Mars. I am of course not treating Pluto as a Planet (as it is no longer categorized as a planet), if I were to count Pluto then it would be the least massive ( 0.0021 Earths).
Mercury is the smallest and the least massive planet, out of the eight in our solar system.
To qualify as a planet, a body has to be approximately spherical (achieving hydrostatic equilibrium under its own gravity), it has to orbit the sun and it has to have cleared its orbit of all other objects - so that at that distance from the sun, there are no other sizable bodies. Theres no set size, but to achieve an approximately spherical shape under its own gravity, a planet would have to be at least around 500-600 miles in diameter.