Coastal Breeze News

By Mike P. Usher What is opposition? It’s when an outer planet is 180 degrees away from the Sun; it rises when the Sun sets and is visible the whole night long. Dynamically speaking, opposition happens when the Earth, on the fast inside track around the Sun, passes the outer planet. Opposition is also the time when the outer planet is closest to Earth (on this lap around the Sun anyway) and thus brighter. Tonight Jupiter is -2.78 magnitude – about the brightest it ever gets. Jupiter reaches opposition about every 13 months; it takes Earth the extra month to ... Read More »

By Mike P. Usher  Tonight Jupiter is finally visible at a reasonable time, but still too close to the horizon for good binocular viewing. Also the Moon is still nearly full tonight – which washes out all the fainter stars, but it’s a good time to try a simple experiment. Everyone is familiar with a huge Moon floating just above the horizon but it shrinks drastically by the time it’s high overhead. This is purely an optical illusion – the Moon does not change size. You can prove it to yourself by marking with a wax pencil its size on ... Read More »

SOUTHERN SKIES  By Mike P. Usher  This particular Autumn is a bad time for early evening planet watchers; bright naked eye planets seem to be missing from the sky. It will be midnight before Jupiter will be high enough for good viewing, Saturn is behind the Sun, and it will be December before Venus will be a decent evening star. It will be spring before Mars and Mercury will be visible at a reasonable hour. At least the glorious summer Milky Way is still visible! You are undoubtedly aware the movement of the sky is a very regular affair; until ... Read More »

SOUTHERN SKIES By Mike P. Usher We talked about the Summer Triangle consisting of Vega, Altair and Deneb last year, and once again like last year the Moon is washing out all the lesser stars. You may wish to wait a few days until the Moon is out of the way before you go star gazing. The three stars of the Summer triangle are buried deep in the Milky Way and their constellations are rich in Deep Sky objects. But before looking for any of them examine the shape of the Milky Way itself. If you are at a dark ... Read More »

By Mike P. Usher  Tonight Uranus is rising; by 11 tonight it should be high enough to view with binoculars. The name, as it is usually pronounced, is a source of endless humor to fifth graders; in fact Isaac Asimov called Uranus the “joke planet” in one of his essays. Nowadays, its recommended pronunciation is “your-an-us” which hardly sounds much better. Historically the Ancient Greeks probably made the word sound more like “Ou-ra-nos.” Although the Ancient Greeks had no knowledge of the planet Uranus (it’s so faint and its movement is too slow) they did provide the mythological background. The ... Read More »

By Mike P. Usher [email protected]  August 12th and 13th are the peak of the Perseids meteor shower; to see them look to the northeast after midnight. The Perseids are one of the more reliable meteor showers of the year, perhaps 60 to 100 are visible each hour when the constellation Perseus is near zenith. Meteors may be seen radiating outwards from Perseus like spokes on a wagon wheel; the point of origin is known as the radiant. Several factors determine how many meteors are visible during a particular night. Time of night, light pollution, the Moon, height of the radiant ... Read More »

By Mike P. Usher By the time you read this you may have seen the first close up pictures of the Asteroid Vesta – the space probe Dawn is scheduled to enter orbit on July 16th. For a brief time you, too, can glimpse Vesta – the only main belt asteroid visible to the unaided eye. (At least forty are visible with 9×50 binoculars at some point in their orbits.) Vesta is an asteroid, an ill-defined term that basically means nowadays any large rock closer to the Sun than Jupiter. Vesta resides in the main asteroid belt, a broad region ... Read More »

By Mike P. Usher We are going to break the usual rule and look at the sky tonight at twilight where we will find the most elusive of all planets, Mercury. There is even a legend that Copernicus, promoter of the sun-centered Solar System, never saw it – though that is hard to believe. Mercury is difficult to find due to its close proximity to the Sun; in fact it is never found more than 28 degrees away from our home star – usually much less. This means that Mercury is never visible in the northern hemisphere when the sky ... Read More »

By Mike P. Usher Coincidentally with the Fourth of July later this week, the stars are putting on their own special show. Scorpius (the scorpion) is both one of the brighter constellations in the zodiac as well as one of the few that looks like its namesake. Mythology of the constellation goes something like this: it is the scorpion that stung Orion to death; now that they are both in the heavens he is careful to keep as far as possible in front of the scorpion lest he be stung again. This is why they are never seen in the ... Read More »

By Mike P. Usher Tonight the Summer Triangle is above the horizon again after its winter absence. The bright trio of Altair, Deneb and Vega lies embedded in the summer Milky Way. Except for the previously mentioned three, there are few bright stars in this region, but there are literally millions of dimmer ones. Scan with your binoculars from Deneb leftwards towards Sagittarius – innumerable stars will be revealed. Even more may be seen if you wait a couple of days for the too bright Moon to get out of the way. On the chart you will see a number ... Read More »

By Mike P. Usher Tonight the Summer Milky Way is rising, almost looking like the beginning of dawn; just above it is the large, but fairly faint constellation of Ophiuchus. It is usually drawn as a man grasping a snake, and as one might expect the name in ancient Greek means “serpent-bearer.” Recently it has become famous (again) as the 13th zodiacal constellation for, as you can clearly see from the chart, the ecliptic runs through it. Every few decades the media treats it as a major discovery, but it’s been that way for all of human history. Ptolemy recorded ... Read More »

By Mike P. Usher Tonight we are going to change our viewing time from our usual 9 p.m. to 11 p.m. until late summer. There are two reasons for this: 1) The longer days of summer mean it is not fully dark at 9 p.m. and 2) the rapidly approaching rainy season means early evening clouds blot out the stars. By 11 p.m. there is at least a chance of clearing, although it’s not usually totally clear until after midnight. The chart tonight is a close up of the southern sky showing due south up to only 30 degrees above ... Read More »

By Mike P. Usher Today we are going to break with our early evening tradition and check out the sky at 6:00 AM Saturday morning. Yes, it’s early, but the unusual sight in the east is worth it. In the eastern sky, just above the horizon is an unusual grouping of planets. Not one, or two but four planets are grouped closely together – Mercury, Venus, Mars and Jupiter. The close grouping is purely a line of sight phenomena though, in reality the planets are many millions of miles apart. Mercury happens to be closest to us at the moment, ... Read More »

By Mike P. Usher Tonight we will look northwards again to the North Star, but if we were in ancient Egypt we would not be looking at Polaris, but the faint star Thuban (aka Alpha Draconis) instead. Because the Moon tugs at the bulge around the Earth’s equator our planets axis very slowly wobbles in a manor similar to the toy gyroscopes you played with as a kid. It’s a very slow wobble to be sure, taking some 25,772 years to trace out a circle in the sky. This movement is called precession of the equinoxes, as the other main ... Read More »

By Mike P. Usher Tonight find the handle of the Big Dipper; now mentally extend the arc of the handle and you will find the bright orange star Arcturus. It’s a magnitude -0.04 star and the brightest one north of the celestial equator. It’s the brightest star in the constellation Bootes (both o’s must be pronounced as separate syllables), who is supposed to be a hunter following the Great Bear, Ursa Major. Now continue the arc from Arcturus and you will end up at the 1st magnitude star Spica, the brightest star in the zodiacal constellation of Virgo. In mythology ... Read More »

Tonight mighty Orion has begun sinking towards the west while the Spring constellations are beginning to rise in the east. Betelgeuse is flagged as the brightest star in Orion in the 400 year old Bayer catalog, but it is a variable star and usually Rigel is brighter. Let’s look at Rigel then and ask how bright it really is. Rigel is one of the brighter stars in the sky tonight – you can see this magnitude +0.18 bright blue giant star in Orion’s lower right corner. Not too far distant from Rigel is the even brighter star Sirius shining at ... Read More »

By Mike P. Usher By some coincidence the brightest stars in the sky tend to appear in the winter. But how bright is bright? Or to put it another way, its obvious some stars are brighter than others; can we assign a value to the brightness so we can make comparisons between stars that might not be visible at the same time? The first person to do so was Hipparchus more than two millennia ago. He took the brightest twenty or so and said “these stars are of the first magnitude” the next hundred were “of the second magnitude” and ... Read More »

By Mike P. Usher After setting a few months ago the Big Dipper has returned to the early evening sky. The Dipper of course is not a constellation but merely an asterism and makes up a portion of the rather large constellation of Ursa Major, the bear. It is an odd fact that roughly half of the world’s cultures regard this grouping of stars as a bear; after all it does not look much like a bear. One possible explanation is that this constellation’s identification as a bear is a shared cultural tradition springing from a common root. If true, ... Read More »

By Mike P. Usher Tonight we look again into the southeast where the ancient constellation Argo is rising stern first into the sky. Argo is no longer counted as one of the 88 constellations visible in the night sky; about two centuries ago it was found to be inconveniently large so it was broken into four separate constellations, Carina the keel, Puppis the deck, Pyxis the compass, and Vela the sails. The old Argo is so large and deep in the southern sky it never is completely above our horizon at the same time, the stern sinking in the southwest ... Read More »

The following viewing schedule is from the Everglades Astronomical Society. You’re welcome to bring your own telescope, but many club members will allow you to take a peek at the heavens from their equipment. The viewing location is in the Fakahatchee Strand. Please call or email for further information and directions. Weather Permitting: 2011 – Starts at Sundown On: January 1 – 29 February 5 – 26 March 5 – 26 April 2 – 30 May 21 – 28 June 18 – 25 July 2 – 23 – 30 August 20 – 27 September 24 October 22 November 19 – ... Read More »