"Dear Neptune" -Mrs. Puff
Aside from having a cool name and yielding a beautiful blue hue in color, Neptune is a planet roaring with interesting events and obscurities. So lets dive into some of them shall we?
Beginning with a little history, Neptune was the last Planet to be discovered, (once again, R.i.p Pluto), and has remained that way for a while. However the possible existence of a ninth planet somewhere very far out there is still in question and many astronomers think it may be a reality.
Discovered in 1846, Neptune was a planet that many believed to exist before it was actually seen. Using gravitational formulas set by Sir Isaac Newton, Urbain Le Verrier, Astronomer and Mathematician, was able to predict the existence of Neptune and how massive it likely was. It wasn't directly observed until September 23rd of 1846 by astronomer Johann Gottfried Galle.
However the truth is Neptune was actually observed before, but nobody knew it was a planet. Famously, Galileo was one to see it through his telescope observations yet mapped it as a star. And nobody could blame them for it either, Neptune, while visible through a telescope cannot be seen with the naked eye, as result nobody came along and notice a familiar small star was missing from where it should be at any point.
Neptune as a planet is quite an interesting one, its wind-speeds are remarkably fast reaching as much as 1500 mph or 2400 kph. These winds are nearly continuous as they glance across the planet and form massive storms. Such as the Great Dark Spot as seen in this famous photo of Neptune.
The storm is the size of our planet, and likely contained wind-speeds outclassing the norm at 1700 mph or 2735 kph. And although it isn't alone, it is figured that the photo taken there was the product of lucky timing, as storms that large are probably rare on Neptune.
The temperature is another strange case. As one may expect, the surface is rather cold, at a frigid -200 degrees Celsius, or -328 degrees Fahrenheit. This is to be expected given its distance from the sun at nearly 2.8 billion miles. What's odd however is that its core is rather hot, around 7000 degrees Celsius, or 12.6 thousand degrees Fahrenheit. More of the planets surface heat is coming from its core than the sun itself. And as result of centrifugal equator bulge, the equator is the coldest of all while the poles are slightly warmer.
Neptune also has a few numbers to go along with it by comparison to other members of the solar system. It has 17 earth masses, this puts it ahead of Uranus in the place of planet mass, making it the 3rd most massive planet, in spite of being smaller than Uranus. This is the result of it being denser. Density is a key factor with the gas giant masses. Jupiter is not only bigger but denser than Saturn so it yield a decent amount more in mass. Neptune as well beats out its counterpart with denser gas distribution. It is in fact, the densest gas giant in the solar system. Partly because of the amount of ice, which is floating around in its outer layers in high quantities. And the dense structure of methane gas, also residing in the outer layers, and also giving it its blue color as a bonus.
However Neptune's color is another thing on its own, while many pictures show a very deep blue hue, Neptune is in fact not as dark as those pictures depict most of the time, it only appears that way because of how its light travels. Pictures taken from close up by voyager 1 show a slightly lighter hue.
There are few things more surreal than being this close to a gas giant.
Those horizontal lines are the result of wind sheer, an atmospheric effect in which strong winds cause gliding surfaces of clouds to rise. This explains why they are not seen on Uranus, as the winds do not hit similar speeds. This raises the question of why Neptune's winds are so fast. It is all the result of that super hot core. Here's what happens, while Neptune's outer layers remain cool, the core's heat heats the layers closer to it. This heat energy rises in places where the pressure is lower, when that heat reaches the surface it is in a spot of low pressure and so cool air rushes into the area. This causes a chain reaction in which air flies around the planet horizontally in a continuous fashion. This illustration shows how convection works in a simple manner.
As of now, Neptune remains the farthest planet from the sun. It's orbit is about 17.6 billion miles, or 23.8 billion Km. As expected, that takes a while to complete. 165 years in fact. Almost twice as long as the next planet inwards. Partly because of the extended distance, partly because the farther away a planet is, the slower it orbits. However the same cannot be said for axis rotation. While Jupiter and Saturn take about 10 hours to complete a rotation, Neptune takes about 16. Still faster than earth though.
Here's another unique tick, every 248 years Neptune actually crosses paths with Pluto, at least it's orbit does. This is due to how the orbits are tilted a bit from each other, so for a time period, Neptune is actually farther from the sun than Pluto.
As a last note, visual observation of Neptune is fairly easy. All you need to know it where it will be. A simple internet search should reveal that fairly quickly. However it won't look like much more than a small blue dot. But it's a cool sight nonetheless.
Above: This was snapped by Hubble
Image Origins:
https://www.emaze.com/@AWLRCFIW/(Neptune)
https://en.wikipedia.org/wiki/Neptune
http://www.setterfield.org/Astronomy/Neptune.html
https://www.mis.mpg.de/applan/research/rayleigh.html
https://www.nasa.gov/feature/goddard/2016/hubble-imagery-confirms-new-dark-spot-on-neptune