Back on Earth, when I used to observe the Moon in the night sky, I can often spot very prominent patches in a shade of gray darker than the rest of the Moon. I once thought, what is it? Is it a man on the Moon? Or is it a rabbit?

Only after landing on the Moon, did I find out, that these are actually the Moon's own seas.

I still remembered when I glanced at the dynamic wallpaper of Serenity's room, which is a map of the near side of the Moon. On the giant patches of gray on the map, I could see labels with what I presume are the names of the bodies of water, such as "Ocean of Storms", "Sea of Serenity", "Sea of Tranquility", "Lake of Dreams", and so much more.

It turned out that the naming scheme of Lunarian bodies of water is quite different from that of Earth; in fact, the Lunarian naming scheme looked like it was meant for a dreamy and surreal world!

Two days earlier, Mercury and I agreed to navigate the seas of the Moon at the garden lunch. Afterwards, I remember having discussed with Mercury about the geography of the Moon, which she said would be more appropriately termed "Selenography", but less commonly known as such. She once spoke of the distance between the midpoints of the Strait of Serenity and the Strait of Tranquility, which separates the Sea of Serenity from the Sea of Showers and the Sea of Tranquility respectively, and I tried hard to map that to the scale of Northern Europe. If I remembered correctly, that should be comparable to the distance between Kultajärvi and the city of Hämeenlinna in the Kingdom of Häme.

I awakened as the Sun shines brightly on the start of a new day. Opening my doors and stepping into the common room, I found Jupiter preparing breakfast for us as usual.

"Morning, Jupiter!"

Turning her head towards me, she greeted, "Hyvää huomenta, Aurora!"

When I heard her greeting me in my own language, I chuckled, complimenting her, "Now even you know how to say good morning in my language!"

Previously, I have only heard Serenity saying phrases in my own language, such as minä rakastan sinua, nuku hyvin and hyvää huomenta. For me, it sounded purely cute and interesting, that Serenity and his sisters would be learning the language I speak.

Looking at the table, I asked, "What are you preparing?"

Pouring some of what looked like whole grains to me into a bowl, Jupiter said, "A nice breakfast with whole grains and protein-rich fermented milk!"

She then turned to me as she continued, "Mercury has consistently reminded us, that a high-protein and high-fiber diet..." and as she positioned her hand over the upper part of her torso, she concluded, "is good for our health, development and well-being."

"She is right," I said as I nodded in agreement. "And perhaps this is why you are so tall and so strong among your sisters!"

She then said, "my mother told us that I would be developing at a faster pace than the others due to my nature as the Sailor Guardian of the largest planet in the Solar system. In other words, I would always be taller, stronger and more developed than my other siblings. Because of this, I always tend to eat more protein-rich food than they do, in order to catch up with my supposedly 'faster' development, and this only ended up with me being even taller and stronger!"

"And so it becomes yet another self-fulfilled prophecy," I giggled, "that Jupiter is the strongest."

Just as all the bowls are readily prepared, I could see Mercury opening her door, stepping out into the common room in her aquamarine gown.

Gladly, I greeted her, "Hi, Mercury!"

The both of us could see her walking closer towards us at the open kitchen, as she said, "Jupiter and Aurora! Good morning!"

Jupiter and Mercury hugged at the very beginning of their day as it has always been for them, at least before my stay on the Moon began.

Letting go of the hug, Jupiter told her sister, "There's one thing you should know, Mercury."

"Yes?" asked Mercury, as she was about to listen what Jupiter would be going to tell her.

"When I was preparing breakfast for all of us, Aurora told me that it is a self-fulfilled prophecy that I am the strongest, because I always eat more than the rest of us and develops more in turn."

Mercury agreed with a nod, and turned to me, telling, "Aurora, you're quite right about Jupiter's self-fulfilling prophecy. I still remembered the Queen telling everyone on Jupiter's ninth birthday about her enhanced growth and how it relates to her place as the strongest Sailor Guardian in terms of physical power."

Jupiter looked towards Mercury, as the blue-haired princess continued telling me, "It's undeniable for me, Venus, Mars and Serenity to have some feelings of jealousy about her being able to be so tall, but then we realized that we all have our unique characteristic that is meant for being the Sailor Guardians of our own planets. Venus is meant to be more athletic to complement her destiny of wielding her sword, while I, for example, has always been more focused on strategy. That's why I like reading books to become smarter, while Jupiter likes to train, cook and eat to become stronger."

Jupiter then put each of the six bowls on the dining table, waiting for Serenity and Venus to come have breakfast together. And she did not have to wait long, since it took no more than a minute for Serenity and Venus to come out of their rooms.

Mercury waved hands at them, "There you are, Venus and Serenity!"

The golden-haired brother and sister approached the dining table, hand in hand, seemingly anticipating the first meal of a new day their sister has prepared.

Seeing Serenity and Venus coming, Jupiter said, "Let's eat!"

The six of us then took seats around the dining table, and started to savor the nutrient-rich breakfast Jupiter has prepared for us.

Later in the morning, we all took the elevator down to the ground floor, making our way to the Royal Pier. We followed the directions in the vast Entrance Hall, making our way to our destination, where we would soon start our journey to the expansive seas of the Moon.

Coming out from the shadows of the Palace Buildings, we now stand at the Southern side of the Moon Palace, with a footbridge to the Royal Pier over a seaside road. The specific pier is exclusively for use by members of the Royal Family, while public piers are also present nearby, down the road.

The Sea of Serenity is true to its name: it is serene and peaceful, and illuminated by the blue sky. It reflects every bit of the landscape, from the mountains to the ridges, and the azure horizon. The Sea is vast, having seemingly no limits, as it meets the sky in a fine cyan line.

A silver-colored vessel was berthed by the Royal Pier, with a golden crescent moon symbol printed on its starboard side. The vessel itself is of a medium size, and it seemed like it could carry at most ten persons.

Princess Mercury was the first to board the vessel, while Serenity and I followed.

"Come, everybody!"

Princess Venus ushered the rest of us onto the vessel, with Jupiter and Mars boarding before her, and Venus herself boarding last, after making sure that every one of us is onboard. She then unberthed the vessel, while Mercury went to the control panel.

Pushing a few buttons, the vessel gradually accelerated, departing into the vast and calm Lunarian sea.

A few minutes into the cruise, Serenity looked back to the city introduced, "the capital of the Moon Kingdom is located near the Southern end of the Caucasus Mountains, a strategic location that lies on the Northern end of the Strait of Serenity, between the Sea of Showers and the Sea of Serenity. Many years ago, the first incarnation of my mother chose to build her kingdom from this location, due to how it connects the 'inner seas' of the Moon such as the Sea of Serenity, the Sea of Tranquility and the Sea of Fecundity, to the larger Sea of Showers and the most expansive Ocean of Storms."

"You know, Serenity?"

Serenity curiously looked towards me, wondering what I would tell him.

"My kingdom also considered many factors when deciding its capital. We decided to built it by the side of the largest lake in the river basin. That way, it is just as easy to reach there from the sea as from the upstream regions. "

Serenity nodded, "I see. Now that map I saw on Earth made even more sense to me..."

Being curious as always, Venus joined our conversation and asked, "What map did you see on Earth, brother?"

He told his sister, "it was a day on Earth, when I saw a wooden boat next to her house. I asked her if she could take me to a cruise around the largest lake of her kingdom, and she agreed, saying that she actually wanted to take me around the lake. We then rowed around the lake, and had a sight of its inflow and outflow points, as well as the castle that stands by the lakeside. And when we returned, Aurora gave me a map of her region of Earth to read."

I smiled to Venus, as I turned towards her. She told me in awe, "I would like to give it a read too, Aurora!"

Responding to her interest in the geography of Northern Europe, I told her, "one day when you come to Earth to visit my kingdom, I promise I'll show that map to you!"

According to Princess Mercury, the Sea of Serenity is known for not having particularly large atolls like the Archimedes and Copernicus Atolls in the outer seas. As a result, most of the sea is moderately shallow, with basalt formed from cooled lava flowing into ancient impact basins as the seabed.

Since there is not much to see in the middle of the sea other than a 360-degree view of the blue horizon, we decided to gradually and steadily accelerate our vessel to higher speeds.

In a few minutes, the vessel went from calmly traversing the waters to blasting and blazing above the sea surface. Such speed was unbelievably fast, even faster than a wind. I doubt this kind of speed is achievable with the current level of technology and engineering Earth possesses.

The vessel sailed to the southeast, and I could see some mountains coming closer to our range. Checking the digital map on the vessel, Mercury introduced, "we are now approaching the Strait of Tranquility, and beyond that strait is the Sea of Tranquility. At the Southeastern edge of the strait, there is the Pilnius Atoll. Shall we slow down and pass by that atoll?"

Jupiter, Venus and Serenity all agreed, "Great idea, Mercury!"

Mercury then started to decelerate the vessel, aiming to slow it down to a calm speed when it passes the Strait of Tranquility.

From the vessel, we could sight Mount Vitruvius to our left, and some hills to our right. Right in front of us is the Plinius Atoll, one of the many atolls on the Moon. Looking from above the water surface, we could see a large and deep lagoon surrounded by the shallow atoll.

Mercury said, "Atolls on the Moon were originally craters that were formed by impact with astronomical objects from outer space, before the Moon Kingdom was built. When the first incarnation of my mother set up the Eternity Main System, these craters in the middle of seas soon became atolls surrounded by lagoons, which support all kinds of beautiful aquatic life."

We all looked from the vessel into the clear waters of the atoll. One could easily see the multitude of fish of various species and vibrant colors, and other aquatic life, swimming dynamically in packs around the atoll. Through reading, I know that atolls like this also exist on Earth, but they are quite far away from my kingdom, and I never had the chance to explore them.

I responded to Mercury, "so this is how atolls are formed from the Moon."

Mercury confirmed, "Correct. Since the Eternity Main System has been set up, there has not been more craters forming on our Moon, as it has the energy to protect us from falling meteorites by rerouting their trajectory, so that they avoid the Moon."

Having newly learnt the fact about the Moon's very own protection field against foreign objects, I commented, "That's cool!"

I then told Mercury, "although there are no atolls in the part of Earth where I come from, I learnt about their existence in geography books that tells about the wonders of my planet. Geologists have came up with theories that explain their formation, one of which had said that they are formed from volcanic islands that eventually submerged. As the island sinks into the sea, coral starts to grow around the submerged hillside. And as millions of years passes, the mountain subsides to the point that it is submerged below the sea, as the coral continues to grow upwards and emerge from the sea surface. This is how atolls and lagoons are formed on Earth."

With fondness in her tone, Mercury responded, "This sounds quite intriguing, and quite different from how it is on the Moon. The Earth has always been known for how natural their environment are with everything, and even the formation of a lagoon takes millions of years."

By then, the vessel was travelling at peacefully slow speed, in a circular motion around the Plinius Atoll. We observed the beauty of the Lunarian atoll and lagoon in great detail, watching the lively scene of thousands of fish enjoying their day in the crystal clear sea.

By the time we have had a comprehensive view of the Plinius atoll, we have already stayed on the vessel for quite many hours. It was then Jupiter suggested, "We've sailed across the Sea of Serenity and explored quite much. Now, after these hours, I'm starting to feel a bit hungry. Shall we return to the Palace?"

Mars agreed, saying, "Yes, let's call it a day."

Also agreeing, Venus said, "Let's go."

The others on the vessel also agreed to Jupiter's suggestion. It seemed that we are all hungry, after spending such a long time cruising around the sea, and it is only natural for us to conclude this sea cruise at this moment.

Having heard us agreeing with the suggestion, Mercury then started to adjust the bearing of the vessel and accelerate, sailing us back towards the Strait of Serenity.

Halfway through the return trip, the Caucasus Mountains begin to appear again in our sight. We aimed for the tip of the Mountains, as we continued to look at the digital map and sail our vessel at the speed of sound.

It took us around an hour to sail across the vast Sea of Serenity, back to the Royal Palace. While we enjoy the views of the boundless sea and the clear horizon, the faraway buildings of the Lunarian capital city started to appear on the horizon.

We returned to the Royal Pier outside the castle, having concluded a nice day of sailing out there in the seas and oceans of the Moon. We berthed and disembarked the vessel, going on our way back to the Palace Building.

"That was a great cruise! Thank you, Mercury!"

Mercury smiled, and responded warmly. "I'm so happy that you get to know more about the true face of the seas of the Moon!"

I chuckled lightly in return, as we promenaded along the hallways of the Entrance Hall to the elevator of the Sailor Guardians' Tower.