The night before our first snorkel  was clear but very windy.  At about 10P twenty  of us went up  to the Observation Deck..  It was pitch black – obviously zero light pollution which was great for star gazing but a little disconcerting finding one’s way while stiff breezes attempted to push us overboard (kidding). Frankly all of the  guests gripped the railing and slid single file  across it until  we all had great vantage points.

Our host for this evening’s activities was Derrick Pitts, a guest lecturer with an impressive resume:

Derrick was lively and quite entertaining – obviously loved  sharing his vast knowledge of the universe – but what was particularly endearing was his method – not lofty with difficult scientific nomenclature but down to earth (no pun intended).

Since the majority of the guests were from the Northern Hemisphere we needed “grounding” in looking at the Southern night sky – and I was delighted to find that Derrick’s choice was one of my favorite constellations – Orion. Using a laser pointer, he helped us locate this large star grouping so we could use it as a marker to discover other heavenly bodies:

Sadly by this time my camera with the 600M zoom had already had its last rites – so I did my best with my underwater camera with extended exposure settings  – not the best for sure – but I will tell you,  in person the sky was overwhelming – so my apologies:

From Orion’s position in the sky, Derrick made it easier to pinpoint other heavenly bodies.   The easiest one really needed no markers – Earth’s  own Milky Way:

The Milky Way is actually  our galaxy. While we can’t see our own galaxy, by extensive star mapping, astronomers have identified our galaxy’s shape as a barred spiral.  From our earthly viewpoint we see a “flat” luminous band of stars as we are looking from inside the galaxy’s dense, flattened disk but it might look something like this:

Facts about our galaxy:

• It is composed of 100-400 billion stars, gas, dust, and dark matter, stretching roughly 100,000 to 200,000 light-years in diameter. TheMilky Way is about 13.6 billion years old.
  • Dark matter is an invisible substance that makes up approximately 85% of all matter in the universe.  It acts as a “glue” holding galaxies together.   It does not emit, reflect, or absorb light, making it undetectable by telescopes, and is only known to exist through its gravitational pull on visible matter. 
• The Milky Way structure consists of a central bar, surrounded by a disk containing spiral arms and a large spherical halo of stars.
• Our Sun is located in one of the spiral arms, about 25,000 light-years from the center
• It takes our Solar System 250 million years to complete one orbit
•  A supermassive black hole named Sagittarius A sits at the center
  • A black hole is a region in space where matter is compressed so intensely that it’s gravitational field allows nothing to escape – not even light
    • They are not “holes” but invisible, dense remnants of collapsed massive stars, often containing the mass of several suns packed into a tiny area. 

We were also able to locate two other galaxies which of course are far, far away:

These are known as the Small and Large Magellanic Clouds/Galaxies.  They are actually  irregular dwarf satellite galaxies of the Milky Way, visible to the naked eye in the Southern Hemisphere.  The Small Magellanic Cloud contains about 3 billion stars and is approximately 200,000 light years away (and may actually be two distinct galaxies one behind the other).

• A light-year is a unit of distance, not time that represents how far light travels in one Earth year, which is approximately 5.88 trillion miles.

The Large Magellanic Cloud is about 163,000 light years away and is massive, containing 30 billion stars.

We spent a number of hours identifying other constellations – like the Southern Cross:

We also were able to see planets and  many other constellations. You can use the star chart as the top of this post to get an idea of the magnitude of what we saw.

As you can see, information about the universe is as immeasurable as the number of heavenly bodies it contains.  It makes my brain explode with thoughts and is truly humbling.