Jupiter 

It's Freezing
Whilst Jupiter’s core is thought to be a hot 24,000°C, its atmosphere is much more frigid at -145°C. These cold temperatures are due to Jupiter’s distance from the sun coupled with its high visual geometric albedo of 0.52. This high albedo (the ratio of shortwave solar radiation reflected by a surface) can be attributed to Jupiter’s high cloud content mainly consisting of reflective ammonia ice crystals. Hence the planet retains less heat and reflects more shortwave radiation into space.

Jupiter has clouds made of crystals
Jupiter’s cloud formation processes are similar to Earth’s, except that in the Jovian atmosphere temperatures are low enough to allow for the condensation of gases such as ammonia and hydrogen sulfide. This results in decks of ammonium hydro-sulfide (NH4SH) clouds, ammonia ice crystal clouds as well as other water crystal and liquid water clouds. 

Jupiter smells different depending on what layer you are in
Whilst smells and aromas would be the least of our problems if we ever got near Jupiter, in layers where ammonia concentrations are high the planet would smell like cleaning products and urine? In deeper layers of hydrogen sulfide, it would smell like rotten eggs, whilst regions with high concentrations of hydrogen cyanide would smell like bitter almonds. 

Contrary to popular belief it’s not all gas – Jupiter is home to the largest ocean in the solar system 
Although it’s commonly assumed that Jupiter is all gas, Jupiter is actually part liquid making the planet home to the largest ocean in the solar system. This ocean consists not of water but liquid metallic hydrogen at a transition point over 20,000 km below the planet’s atmosphere. Here molecular hydrogen is subjected to extreme pressures and temperatures that compress hydrogen into a metallic state (this occurs at around 3,000,000 bar; >6000K). At this state individual hydrogen atoms begin sharing their electrons (which does not occur in hydrogen’s liquid or gas state), allowing for the conduction of heat and electricity. It is actually the convective motions in this conductive liquid metallic hydrogen coupled with Jupiter’s fast rotation which drives the planet's magnetic field.  

If you took a compass to Jupiter, it would work  
This is due to Jupiter having the strongest magnetic field of all the planets in the solar system. Its magnetic field is 16-54x more powerful than that of Earth’s and is said to extend up to 7 million km.  

Jupiter radiates back into space double the energy it receives from the Sun  
Like many terrestrial rocky bodies, Earth experiences a radiative equilibrium or heat balance which means that the energy we receive from the sun is balanced by an equal amount of energy radiating back into space. Jupiter however radiates back into space double the energy it receives from the Sun. This occurs partly due to its high albedo (due to reflective clouds), however primarily is fueled by radioactive decay, contraction, and a residual heat coming from internally as a result of planetary accretion. In other words, Jupiter’s core is still cooling from its own formation 4.6 billion years ago. This residual heat is what drives its convection currents, resulting in its turbulent weather, and its distinctive banding of clouds.    

Earth and Jupiter are more similar than you’d think: 
Similarly, Earth’s core is also still cooling and the heat that was leftover from its formation continues to drive everything as we know it from mantle convection and plate tectonics to magnetic field generation. The Earth’s core is set to cool and solidify in about 91 billion years (astronomers predict the sun will burn out in 5.5 billion years, engulfing us long before this happens anyway). If our core solidified, we would not only lose our magnetic field but compasses would stop working, birds would no longer know where to fly and migrate, and the Earth’s atmosphere would disappear.