C is for Cosmic

cosmic (adjective): 

1. relating to the universe and the natural processes that happen in it.
2. (informal) vast, very great
3. (spirituality) relating to the concept that everything in existence is interconnected as one vast, unified whole.

Finally, Marvel Comics fans will of course know that cosmic radiation (the leftover energy from the Big Bang) was responsible for the creation of the Fantastic Four. 

W is for Water

Here's seven fascinating facts about water...

1. Water comprises 71% of the Earth's surface, mostly in seas and oceans. Because the oceans reflect blue light, the Earth appears blue from space. 
2. 97% of the water on Earth is salt water, with an average salinity roughly equivalent to 34 grams of salt in 1 kg of seawater.
3. The balance therefore represents fresh water, which is rather unevenly distributed on the Earth. 68.7% of this fresh water is trapped in glaciers, ice caps and permanent snow. Of the liquid surface fresh water, 87% is contained in lakes, 11% in swamps, and only 2% in rivers. Small quantities of water also exist in the atmosphere and in living beings.
4. The human body contains anything between from 55% to 78% water, depending on age, health, weight, and sex. To function properly, the body needs to be hydrated - the NHS tell us that we should drink about 1.2 litres (six to eight glasses) of fluid every day to stop us getting dehydrated.  If the weather is hotter, the body will need more than this. We also get some fluid from the food we eat. 
5. 70 -75% of the human brain is water.
6. Water is unusual in that its solid form, ice, is less dense than its liquid form, which is why ice floats. 
7. Water is often called the "universal solvent" because it dissolves more substances than any other liquid.

S is for Space

Of course! We are one big, happy fleet! Ah, Kirk, my old friend, do you know the Klingon proverb that tells us revenge is a dish that is best served cold? [pause] It is very cold in space!
Khan, from Star Trek II: The Wrath of Khan (1982)

So, is it true that space is always cold?

Actually, you are asking the wrong question. Space is mainly empty - no air, no matter, nothing. It’s only when you put something in space, like an asteroid, a satellite, or even an astronaut, that you can measure temperature. If you're in total darkness at the coldest spot in the known universe, the vacuum of space can get down to -270.45 degrees Celsius (reportedly the temperature of the cosmic microwave background radiation, which permeates the entire Universe). Which is as cold as it can get.

However, in direct sunlight near Earth, temperatures can vary wildly. A piece of bare metal in space, under constant sunlight can get as hot as 260 degrees Celsius. This is obviously dangerous to astronauts who therefore take great precautions to protect themselves if they are called to carry out an EVA (extravehicular activity, or spacewalk). That's why astronauts wear reflective white spacesuits, complete with both heaters and cooling systems.

F is for Flag

It's an iconic image, isn't it? The Stars and Stripes on the moon.

Except, you won't see this if you go there now.

NASA has now confirmed any American flags that are still in situ on the moon are now totally white.

According to lunar scientist Paul Spudis:

For forty-odd years, the flags have been exposed to the full fury of the Moon's environment – alternating 14 days of searing sunlight and 100° C heat with 14 days of numbing-cold -150° C darkness. But even more damaging is the intense ultraviolet (UV) radiation from the pure unfiltered sunlight on the cloth (modal) from which the Apollo flags were made. Even on Earth, the colours of a cloth flag flown in bright sunlight for many years will eventually fade and need to be replaced. So it is likely that these symbols of American achievement have been rendered blank, bleached white by the UV radiation of unfiltered sunlight on the lunar surface. Some of them may even have begun to physically disintegrate under the intense flux.

The NASA website about this can be read here.