which planet has an orbital eccentricity most like the orbital eccentricity of the moon?
464949
My guess would be Pluto
780238
orbit:    57,910,000 km (0.38 AU) from Sun\n        diameter: 4,880 km\n        mass:     3.30e23 kg\nMercury is the innermost and smallest planet in the solar system, orbiting the Sun once every 88 days. It ranges in brightness from about −2.0 to 5.5 in apparent magnitude, but is not easily seen — its greatest angular separation from the Sun (greatest elongation) is only 28.3° (it can only be seen in twilight). Comparatively little is known about the planet: the only spacecraft to approach Mercury was Mariner 10 from 1974 to 1975, which mapped only 40%–45% of the planet's surface.\n\nPhysically, Mercury is similar in appearance to the Moon as it is heavily cratered. It has no natural satellites and no substantial atmosphere. The planet has a large iron core which generates a magnetic field about 1% as strong as that of the Earth. Surface temperatures on Mercury range from about 90 to 700 K (-180 to 430°C) , with the subsolar point being the hottest and the bottoms of craters near the poles being the coldest.\n\nThe Romans named the planet after the fleet-footed messenger god Mercury, probably for its fast apparent motion in the twilight sky. The astronomical symbol for Mercury, displayed at the top of the infobox, is a stylized version of the god's head and winged hat atop his caduceus, an ancient astrological symbol. Before the 5th century BC, Greek astronomers believed the planet to be two separate objects: one visible only at sunrise, the other only at sunset. In India, the planet was named Budha (बुध), after the son of Chandra (the Moon). The Chinese, Korean, Japanese, and Vietnamese cultures refer to the planet as the water star, based on the Five Elements. The Hebrews named it Kokhav Hamah (כוכב חמה), "the star of the hot one" ("the hot one" being the Sun).
827703
It has a thick, dense atmosphere that is almost entirely nitrogen, like 98%. It is one of only four celestail bodies with a thick atmosphere: earth, Venus, Mars, and Saturn's moon Titan. Other planets or moons have very thin, wispy atmospheres about 1/800,000 that of earth's, but these are nothing more than trace gases and not a true atmosphere.
892847
I would say Europa and titan. Europa is unlike any other body in the solar system, it is not jupiters smallest moon rather the smallest of the galilean moons of jupiter with a diameter of 3100km. Its surface is among the brightest in the solar system, a consequence of sunlight reflecting off a relatively young icy crust. \n\nIts face is also among the smoothest, lacking the heavily cratered appearance characteristic of Callisto and Ganymede. Lines and cracks wrap the exterior. if you were to scale Europa down it would probably be a smooth as a billiard ball. Scientists believe that beneath Europa's icy surface lies a liquid ocean which has the possibility of harbouring life. Let me make myself clear, we're not talking about intelligent life, but rather life that could be very similar to what is found at the bottom of our oceans. \n\nEuropa has a very tenuous atmosphere which is mostly made up of oxygen. Unlike oxygen on Earth however, which is created as a byproduct of photosynthesis in plants, oxygen on Europa is likely to originate when charged particles from the Sun hit water molecules on Europa’s surface. The water molecules are broken into hydrogen and oxygen atoms, and sometimes recombine to form hydrogen and oxygen gas. This kind of environement would make it an ideal habitat for life and very interesting for exobiologists.\n\nTitan would also be extremely interesting to exobilogists.It is the only moon in our solar system with a very thick atmosphere and  like Earth's atmosphere, the atmosphere on Titan is mostly made up of nitrogen. Unlike Earth however it is inhospitable to life due to the lack of atmospheric oxygen and its extremely cold surface temperatures (-183 degrees Celsius) . \n\nAlong with nitrogen, Titan's atmosphere contains a significant amount of methane. The only thing missing for Titan is a little bit of heat. What we know for sure is that the sun is getting warmer by approximately 10% a year. What this means is that in the future, the sun will begin to warm the surface of Titan and therefore give it the possibility of giving birth to life. With the amount of methane in its atmosphere a fair amount of heat would become trapped as methane is a very powerful greenhouse gas.\n\nHope this has helped you out :)
476884
Venus rotates clockwise (as seen from Earth) in retrogate rotation as well as Uranus and Pluto. However, it is the only terrestrial planet that rotates in the opposite direction. The theory is that a large asteroid impacted it and that reversed its motion. As a result, it orbits the Sun faster than it rotates, creating a hostle environment with hot surface temperature, making it the hottest planet in the solar system, (hotter than Mercury, although it is closer to the Sun).
1727
Yes -- in fact you are living on one.  The earth and moon is quite unusual in being relatively the same size to earth other compared to other moons around other planets in the solar system.\n\nIn that respect you can consider the earth and moon as being twin planets.\n\nAs to how often this happens outside the solar system, you would probably have to wait a few years as we have only just started to be able to detect planets around nearby stars but currently have no real means of actually observing them.
91267
You are referring to a concept in planetary astronomy call inclination of orbit.  The "disc" that the Earth revolves around the Sun on is called the ecliptic plane.\n\nTechnically speaking every other planet has some orbtial inclination or tilt of their disc.  But it is very small so the eight major planets are said to orbit in roughly the same plane (ecliptic).  \n\nPluto is different.  Its orbital inclination angle is about 18 degrees with respect to the ecliptic.  That's big compared to the other planets. \n\nNow the question is why are the eight major planets in the same plane?  Why is Pluto not?\n\nWhen the solar system formed it was originally a giant sphere of gas and dust and over time was gravitationally attracted into a compacted sphere.  When this happens systems need to conserve angular momentum.  This results in the sphere becoming flattened.  This flattened sphere now looks like a disc.  The disc is roughly the ecliptic plane. An analogy to this scenario is pizza dough being spun by a chef into a disc. \n\nPluto, it is believed, was probably originally part of this disc but later had an intereaction with another object which since changed its orbit.
523675
Well geocentric theory by Ptolemy, as stated a while ago is the "earth-center" theory, this means that the earth is the center of the universe and all the celestial bodies revolved on it. The Heliocentric (by Nicolaus Copernicus), states that the sun is the center of the solar system, thus all the planets revolve on it. Both theories assume that the orbits of the planets, planetisimals, and other heavenly bodies are circular, but that is wrong. This was disproved by Johannes Kepler, accdg. to his famous Kepler's 1st Law, and all of his laws stating that planets revolve around the sun in varying eccentricities, (Venus has the almost perfect circle, and Pluto has the most ellipse orbit). He then favored Heliocentric theory.
219947
Of the inner, rocky, planets, Mercury and Venus have no moons, Earth has one, and Mars has two tiny little ones, called phobos and deimos (fear and hatred). Our moon is actually named Luna.
168006
If it doesn't move or twinkle, it is the planet Venus.\n\nThis answer brings me to level 3.  Thanks all!
577490
N0-Venus and Mercury are the only planets that don't, perhaps because being close to the sun reduces the ability to hold onto a moon.
627517
The sun is the center of the solar system, revolving around it are the nine planets namely: mercury, venus, earth, mars, jupiter, saturn, uranus, neptune and pluto.
1112620
Earth.  But one of them is not a true moon.  It's only a temporary one.
141708
Yes. It's actually in our own solar system.  Whether it is a planet or not is the real question.  It is really small.  While bigger than pluto, it is still smaller than the Earth's moon!
905784
what is the coldest planet
1097603
The order of planets? \n\nMercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto
57986
if it is extemely bright, then it is most likely the planet Jupiter. The moon moves a lot each day, so you need to say exactly what day and time you saw it.