From largest to smallest:
Universe, galaxy,nebula,solar system, star, planet
Planet Solar System Galaxy Universe
Starting from least to greatest magnitude in size: Earth Sun Solar System Milky Way Galaxy Universe
A solar system is smaller. There are billions of solar systems in a single galaxy.Each star is a solar system. (some have planets, some don't)When you look at the sky at night, every star is a solar system and all of them are part of the Milky Way galaxy.A galaxy cluster is a group of galaxies.
In order from smallest to largest: Solar System, Galaxy, and Space.
Universe, Cluster, Galaxy, Star, Planet NB: Some stars are smaller than planets.
Saturn is the 6th planet in the Solar System.
In order, the planet after Earth is Mars.MercuryVenusEarthMarsJupiterSaturnUranusNeptune
In general, it's safe to assume that traveling shorter distances in outer space is, and will continue being, faster than traveling larger distances.The distances between planets within our own Solar System are in the order of light-minutes to light-hours, i.e., it will take light minutes or hours to go from one planet to another. The distances to the closest stars (other than the Sun) are in the order of a few light-years. For example, the closest star (other than the Sun) is at a distance of about 4.2 light-years. The distances between nearby galaxies are in the order of hundreds of thousands to millions of light-years.
Okay, there are two problems with your question. Firstly, define space. Like, do you mean our solar system, galaxy or the universe in general? Secondly, do you consider Pluto a planet anymore? If you're just talking about the solar system, no. The second smallest planet in our solar system is Mars. This does not include Pluto. The size order of all the planets is: Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mercury and then Pluto (if you still consider it a planet). Our galaxy is huge and could contain millions of other planets ranging in size from the size of a pea to the size of a small star. The definition of a planet is spherical object which orbits around a star. Even though our galaxy is huge, there are millions of billions of other galaxies out there, many bigger than ours, so there is no chance that out planet is the second smallest in the universe.
The planets are shown on the inside of the planet Magrathia. They actually manufacture planets to order.
For our Solar System the order from largest to smallest is :-JupiterSaturnUranusNeptuneEarth