The Sons of Perseus

The Sons of Perseus

09 August 2012

There is quite a lot going on this Saturday night/Sunday morning; the conjunction of Spica, Saturn and Mars continues as a celestial triangle gradually becomes a line of 1^st-Magnitude “stars” in the evening sky, a major meteor shower reaches full intensity (its “peak”), and the Moon plays ‘tag’ with two bright planets.  Plenty of excitement for the evening observer and early-riser to enjoy, so lets get started!

First, an update on the ongoing conjunction of Saturn, Spica and Mars.  Over the past week Mars has moved eastward and will be passing between stationary Spica and slow-moving Saturn during the next week.  Even now, as it draws “nearer” the ringed planet and distant star, Mars has moved close enough that you can easily view all three simultaneously through binoculars.  Compare the members of the triad members’ relative brightness and hue—what a terrific contrast of colors!

Keep an eye on these three—the show isn’t over.

Now, for the Main Event.  On Sunday morning the Perseid meteor shower will reach it’s peak for this year; over the past few weeks we’ve been seeing more and more of these “shooting stars”, and the time has come at last for the grand finale.  The Perseids (the name is Greek for “the sons of Perseus”, a reference to the mythological hero) have been observed for at least 2000 years, and are one of the year’s most impressive displays of celestial fireworks, with up to 80 bright meteors (and hundreds of dimmer ones) visible to the naked eye per hour at peak. 

The best time to observe meteors is in the three to four hours before dawn on Sunday, when Earth’s rotation brings the shower’s “radiant” (the area of the sky from which the meteors appear to move outward from) up in the eastern sky.  As the name suggests, the Perseid shower’s radiant is located in the constellation Perseus (see the map below), but don’t concentrate your viewing on that spot alone.  Pick an area with as few lights, buildings or trees as possible, lean back so you can comfortably watch your chosen “sector” (I usually use an air mattress or lawn recliner chair), have a thermos handy and bug-repellent ready, and enjoy the show.

The closing act for the night will be the view to the east an hour or two before sunrise; the waning crescent Moon, 1^st-Magnitude star Aldebaran, Jupiter and Venus will be putting on a lovely display.  Jupiter and Aldebaran (alpha Tauri) will be above the Moon, and Venus (brightest thing in the sky after the Moon) will be low above the horizon. 

I hope you all can get out for at least part of Saturday night/Sunday morning’s sky show—you don’t need to put in an all-nighter (though I probably will!) to observe four planets, the Moon and one of the most amazing meteor showers of the year.  Let me know what you do see of the night’s attractions by writing to my shore-side email (navalgamer@afgimail.com) , and above all—be safe out there in the dark!

Tom Epps

Able Seaman

USNS Joshua Humphreys

Persian Gulf

Photo Dump

08 August 2012

Welcome back to All @ Sea!, my effort to illustrate in my own words and images what it is like to live and work in the great ships.  My name is Tom Epps, I’m 50 years young and a veteran of 24 years’ service in the United States Navy plus nearly 8 years sailing in the US Merchant Marine, in the Gulf of Mexico “oil patch” and the Navy’s Military Sealift Command (MSC).  Currently I am working aboard USNS Joshua Humphreys, a replenishment oiler operating in the Persian Gulf region; her job is to provide USN and Allied warships with fuel, water, food and other stores that keep them sailing and carrying out their missions.

 HMS Diamond On Approach...

...And Alongside USNS Joshua Humphreys

Diamond Receives Fuel From T-AO 188

 

I would like to thank All Hands for the kind comments I’ve received in recent months about my postings and photographs as I’ve sailed in Joshua Humphreys; our voyage has carried us from the northern Persian Gulf south to the Horn of Africa and north to Suez, and it has been a busy and rewarding cruise.  Now, however, the time is come to say “farewell” to Humphreys and her fine crew; my tour of duty here is done and this coming weekend I ought to be flying back to the States for some R&R before the next voyage begins.  A few months of leave and some refresher training, and who knows where my next missive might originate!

French Frigate Guepratte On "Plane Guard"

I will of course be continuing to post on the All @ Sea! Blog (gloriousseas.blogspot.com) while ashore—there are plenty of sea-stories yet to tell, after all!  I’ll also continue with my “Weekend Astronomy” bulletins when interesting stargazing opportunities present themselves—and there just happens to a good ‘un this weekend.  Stay Tuned!

 

Frigate HNLMS  Evertsen makes a handsome approach!

Evertsen's Lynx helo snaps our photo!

I’m going to close out this voyage with a few photos of ships that have come alongside for fuel in recent weeks.  In actuality this represents only a small fraction of our recent “business”, but I don’t always have the luxury of time to take photos of the ships that avail themselves of our services. (occasionally I actually work…)  I hope you will enjoy these images!

Tom Epps

Able Seaman

USNS Joshua Humphreys

Persian Gulf

And we close this voyage with the powerful South Korean frigate Wang Geon...

Celestial Triangle

Good Evening, Shipmates!

I’d like to invite you all to step outside this Saturday and Sunday about an hour after sunset and look to the west; if you have clear or mostly-clear skies, a reasonably low horizon and not too many lights interfering with the view you’ll see three bright “stars” in a small, almost equilateral triangle formation, gleaming in the late twilight. All three will be of approximately the same brightness, but of wildly differing colors—one a steady golden hue, the second orange or yellow-brown, and the third a twinkling light blue. Unlike the annular solar eclipse in May or the Transit of Venus in June, you won’t need a telescope or special filters to enjoy this vista, but a pair of binoculars will show their colors plainly. Be sure to bring the kids out for this one, and have some fun with the facts and figures listed below.

So, what are we looking at? Most of you will already have guessed that one or more of our targets are planets, and you’re right; we are looking at a Conjunction (an apparently close approach of two or more celestial bodies as seen from our perspective) of the planets Saturn (Yellow or Golden), Mars (the Angry Yellow-Brown Planet) and Spica (alpha Virginis), the brightest star of the constellation Virgo and the 15th brightest star visible in our skies. As celestial events go this kind of apparition isn’t really very rare, but it is quite lovely, and given all the attention being paid to Mars these days quite an appropriate reason to brave the mosquitoes on a warm August evening.

As readers of my Blog will know, I have a soft spot for our ruddy, diminutive neighbor—the “fourth rock from the sun”. I’ve watched it through the telescope for much of my life through a succession of “oppositions” (see the Blog entry “Red Planet” for details of my obsession with the God of War) and kept careful track of our unmanned explorations over recent decades. A small constellation of orbiting probes have been scanning the planet for quite a few years, and rovers slowly crawling the Martian landscape have answered many of questions (and raised many more, which is as it should be) about the geology, weather and history of Mars. This weekend, in fact, is expected to mark a milestone in our Martian study; during Sunday night the largest interplanetary rover yet—NASA’s “Curiosity” is to enter our brother planet’s atmosphere and land to begin a new phase of the search for answers. “Curiosity” is a very ambitious program—and a risky one—but I await work of its safe arrival in Gale Crater with great anticipation.

On to Saturn. The sixth world out from the Sun, most famous for it’s spectacular and intricate system of rings, has also visited by man’s robotic emissaries. Even now the nuclear-powered Cassini probe orbits the “Lord of the Rings”, measuring and imaging the massive gas-giant planet’s storms, rings, and many moons. Run a search online for Cassini images of Saturn; prepare to be amazed!

Spica, as noted above, is one of the brighter stars gracing our skies, a Blue Giant binary (double star) over 10 times the mass of our Sun. Its companion star, which orbits the primary every four days, weighs in at over 7 times the mass of the Sun as well, making this a pretty impressive system. Spica is one of the closest Blue Giants to Earth.

Think about that for a moment. As you enjoy the quiet spectacle of the conjunction, and perhaps watch in weeks to come as the “Dance of the Planets” continues with Mars closing in on Saturn and both changing position relative to Spica, consider that Mars is the nearest of these three objects at an approximate distance of 240 million kilometers, Saturn next at about 1.5 billion km, with Spica a mind-pummeling 2.4 quadrillion kilometers*. Put another way, the Sun’s light reaching us now was reflected from Mars’ oxidized surface 14 minutes ago, Saturn’s icy rings and cloud tops nearly an hour and a half back in time, and shone out from Spica’s twin suns over 260 years in the past (in approximately 1752, the year that Ben Franklin demonstrated the principles of electricity using a kite, a key, and a thunderstorm!).

With all the distances involved, and the relative sizes of the participants in this celestial show, I think perhaps the most impressive fact is that the apparent brightness of each of our three neighbors is about the same; two planets, one tiny and the other the second largest in our solar system, and a double star incredibly far removed from our Solar System, all shine in the sky with nearly the same brightness, each in their distinct hues of red, gold and blue. Beautiful!

Space, as Douglas Adams once put it, is big. Really big. And this conjunction of two planets and a bright star is an opportunity to experience and share some appreciation of the scale of our Solar System and stellar neighborhood. It’d also be a good opportunity for a barbeque! So enjoy the burgers and steaks, and the show in the western sky; I’ll be watching as well from Joshua Humphreys’ bridge wing, out here on the Blue Stuff.


Tom Epps
Able Seaman
USNS Joshua Humphreys
Persian Gulf



* Please let me know if I flubbed the maths on that one!