Saturday, June 22, 2013

The Superlative Moon

Hello, Shipmates!
By now I have no doubt that most of you have heard some small part of the “Super Moon” hype—at best you’ve been informed that the Full Moon on Sunday night will appear somewhat larger and brighter than usual, and at worst you’ve been treated to the “doomsday” scenarios that connect the “Super Moon” to floods, earthquakes and bizarre weather around the globe, usually accompanied by “photoshopped” images displaying a Moon of ludicrously impossible apparent size, dominating a skyline.

Here’s one now…

Of course, there is no known relationship between the Moon motions and such disasters, beyond the normal effects of the tidal effect that it has on our planet’s oceans and crust; the Moon will be no closer tomorrow night than it has hundreds of thousands of times in the past, and will have no more effect than usual, with the exception that many, many more people than usual will be out looking at it!

So what is happening here, that our companion world will appear up to 18% larger –and 30% brighter—than a normal, run-of-the-mill Full Moon does each and every month (a measure of time that originates in the orbital period of our natural satellite—perhaps we should call it a “Moonth” instead)? It’s quite simple, actually…the Moon orbits Earth along an elliptical path, taking 29 53 days to complete each journey from New Moon through Waning Crescent, First Quarter, Full, Last Quarter and back to New again. Since its path is an ellipse (above) the distance from Earth to Moon varies considerably during the course of a single obit, with the near-point of it’s path (“Perigee”) being considerably closer to Terra than the far (“Apogee”).

It is on those occasions that the Moon reaches that near point of Perigee at a time close to the Full Moon that a “Super Moon” (the astronomical term for this event is a “Perigee-Syzygy” for the combination of a Perigee with Syzygy, or the alignment of Sun, Earth and Moon) occurs in our skies. Of course the Moon reaches Perigee every month, but the effect of a larger-looking Luna is less obvious when the Moon is a crescent- or Quarter-phase, or especially New. Just as importantly, most people hardly notice those less-brilliant apparitions of our natural satellite; the sight of a Full Moon, however, can stop folks in their tracks!

So plan to get outside tomorrow evening and enjoy the Perigee-Syzygy (THAT name will never catch on!). Try to go to a location with a fairly clear Eastern horizon just about sunset; then you can enjoy the sight of our Moon rising above the trees (or water, buildings, mountains, etc.) and the effect of its brightening as the sky darkens. Print out the attached moon map and see how many lunar features you can identify with your naked eye or with binoculars. Got a digital camera? Try taking several photos using Manual settings, adjusting ISO, focus and exposure to get the best image you can.

And as you gaze at our Moon, think about what you are seeing. You are looking at another world, the only body in the Solar System that we can regularly study without benefit of a telescope, without special filters, and still perceive actual details of its surface. And the only celestial body that bears human footprints—that members of our frail, troubled species have actually walked upon its surface. More than that, without the Moon, it is very possible that we wouldn’t be here to enjoy our view of and to ponder our relationship to it.

So show Luna some respect, and look up more often—you may find that our Moon is always “Super”.

Tom Epps
Operations Chief
USNS Alan Shepard

P.S. Announcing the "Super Moon" photo contest: send me your best picture of Luna, and tell me of your experience…I'll post the best of them here.

The Alan Shepard Observatory

First Light

On the evening of 25 May Alan Shepard’s bridge team watched a lovely spectacle from the bridge; only a few minutes after sunset the members of the watch could see a brilliant point of light about ten degrees above the western horizon. It was quickly joined by a slightly dimmer spark above and to the left of the first, and finally a third gleamed in the hazy twilight, a dazzling triangle of "stars" shining between the clouds.

What we were seeing that evening was a conjunction of three planets; Venus, Jupiter and Mercury. The four of us on the bridge enjoyed the view for nearly a half hour before the three worlds vanished into the dust-laden air of the horizon. They were a brilliant sight through binoculars; I could just fit all three planets into the 5-degree field of view.

I’d been aboard since 14 May, but between the murky skies to be found in the Persian Gulf and the hectic pace of the turnover I was receiving prior to assuming my duties as Ops Chief I’d not had any real opportunity to star-gaze; in astronomical parlance this conjunction of three ‘wanderers’ is known as “first light” for me aboard this ship. I find it quite appropriate, in fact, to commence astronomical observations aboard a vessel named for a Mercury Program astronaut with a sighting of the elusive planet Mercury itself!

Under the Dome

Alan Shepard is not my first sea-going observatory; since 1981 I have (rather selfishly) used nearly thirty vessels as roving platforms for viewing the heavens, staying up long after my assigned duty hours to watch the skies. In fact, the vast majority of the entries in my Observing Journal over the past three-and-a-half decades recount the observation of meteor showers, solar and lunar eclipses, planets, stars and other “deep sky” objects from pitching, rolling decks. Such is the nature of my career @ sea; that I am rarely to be found at home and able to use my telescopes there for their intended purpose of exploring the visible universe.

I have to leave my heavier instruments behind when I come to the sea; my telescopes packed carefully away, eyepieces, tripods and the hundred peripheral parts and pieces boxed and placed into storage. I have learned that in the shipboard environment they would be useless; extra baggage to carry to faraway ports only to languish in a locker, delicate optics and mechanisms risked to no advantage. Long experience has taught me that the best astronomical instrument for this environment is a pair of trusty binoculars; when I travel to meet my newest vessel I carry mine with me; sturdy 10x50 instruments useful for spotting that dhow on the horizon as well as observing the motions of Jupiter’s satellites or studying our own moon’s features.

Starry Night

Yes, my observations are limited but, Ah, the trade-off! Far from land and the light-polluted coastal realm, I am routinely able to see the night sky as few land-dwellers can; with no intrusive city lights to mask the heavens they blaze forth in dizzying splendor, much as our distant ancestors must have seen them in the time before artificial lighting. From Shepard’s deck I can see the Milky Way arcing overhead as no-one in a town can see, the light of its multitudes making as if to drown-out the dimmer stars of the familiar constellations, blurring the lines of Swan, Eagle, Fox and Scorpion.

And between those stars, wonders! Nebulae bright or dark against the background glow of a hundred-billion stellar candles, open clusters with their often oddly regular patterns of stars like strings of pearls, globular clusters blurry and spherical, and the galaxies, distant and often hard to spot, each a stellar “city” in its own right, home to its own multitude. They tease the eye, one moment invisible, the next an obvious spot of cosmic “fuzz”, and then vanishing again.

And still more to see; through my binoculars the classical planets lie within reach. Mercury, Venus, Mars, Jupiter and his moons, Saturn and the far-away ice-worlds of Uranus and Neptune. The brighter asteroids I regularly watch as they silently play amongst their larger cousins, and the comets, slowly following gravity’s summons diving down into the Sun’s warmth before rushing to escape again, dashing back to the outer Solar System as if Sol’s heat had scorched their tail-feathers! They are the leftovers of creation; the flotsam and jetsam of the sky.

The Lights Go Down

This is my world of night, the time and place where I feel most entirely at peace. Deck rolling beneath my feet, wind whistling in the rigging, dolphins splashing and playing in the phosphorescence of the wake. And the sky above, slowly shifting from east to west as the night wears on, Gemini and Auriga setting on the port bow even as Hercules and Lyra rise from the haze on the starboard quarter. Arcturus overhead and Spica due south, paired with Saturn; all old friends to be greeted and admired. A flash of light to the north; a bright meteor has neatly bisected the “scoop” of the Little Dipper, leaving a fading trail of green mist.

Welcome to the Alan Shepard Observatory. I wonder what the night holds for us.

Tom Epps
Operations Chief
USNS Alan Shepard
The Persian Gulf

Sunday, June 9, 2013

Changing Course II

USNS Alan Shepherd

"Amateurs talk tactics; professionals talk logistics."
(Military quote attributed to practically every great general who ever lived)

It's a familiar scene; a resupply rendezvous on the open sea between three grey vessels. The replenishment ship takes "tactical control" of the two warships, then directs them to their stations while maintaining a precise course and speed so that the two combatants can orient correctly on the formations' "guide".

Soon heavy wire-rope cables will physically join their hulls and fuel will pulse through massive hoses; all the while the heavy beat of rotor blades fills the air as a heavy-lift helicopter conveys cargo from flight deck to flight deck. Forklifts position enormous "lifts" of palleted cargo for transfer while line-handlers, winch operators, supervising Boatswain's Mates, and helo control officers perform the industrial ballet by which navies are refueled and resupplied at sea.

Puma 06

Puma 06

Puma Vertrep of USS Carter Hall and USS San Antonio

Suddenly the fueling, the cargo transfer are complete; at a signal from the supply ship the small formation disperses as the combat ships separate and "proceed on duties assigned". In minutes they disappear over the horizon on their various missions and the replenishment unit comes about, shaping course for the next rendezvous, the next scheduled event. There are other "customers" out there that need fuel, food, ammunition and mail.

HMAS Toowoomba

PNS Tippu Sultan

Puma 06 and USS San Antonio

Another UNREP completed, another mission accomplished. Such a dance of machinery and people does not happen by accident; as in any complex undertaking the pieces do not fall automatically into their places to make it all "work". The event must be carefully scheduled, coordinated, and plotted days and even weeks in advance to ensure a successful resupply at sea. All the players must understand their roles in the play, all the materiel and equipment must be prepared, tested and staged, and every possible contingency--weather, shipping traffic, mechanical breakdown, and even enemy action--must be prepared for lest the operation fall apart in mid-execution, endangering ships, aircraft, and lives. There must be a solid, universally-agreed-upon, well-briefed plan.

My plan.

The rendezvous with and UNREP of USS Carter Hall and USS San Antonio in the Gulf of Oman a week ago, which the accompanying photos illustrate, was my masterpiece in the older sense of the end of my apprenticeship and the true beginning of my new career as an Operations Chief with Military Sealift Command (MSC). To bring three mighty ships and their crews together with one purpose I had to negotiate with my opposite numbers aboard them; I had to understand their requirements and limitations as well as our own in order to prepare my briefings and plots. I had to consult 'Shepard's Captain, officers and helo crews repeatedly to ensure that the developing concept of operations was workable, and their feedback was invaluable as I trimmed the rough edges from the plan.
Then, with the "customers" on the horizon, I had the duty of actually driving the process, communicating intents and last-minute information and orchestrating the entire event.

The old saying that "No battle plan survives contact with the enemy" could be well applied here; there were minor problems in the execution of the UNREP, and some improvisation was required, but in the end we had an effective, safe transfer of stores and fuel and all objectives were met; I even had the pleasure of receiving a "well done" from our Captain as the party ended.

I'm proud of my accomplishment, and also humbled by it; my "lessons learned" from this particular event fill three pages in my wheelbook, and though the UNREP went off well I am more aware than ever of the responsibility I bear for this and future operations. The learning process has only begun, and I look forward to the challenges to come.

I think that this change of course in my life and career came at just the right time.

Tom Epps
Operations Chief
USNS Alan Shepard

USS Carter Hall