Around 4.5 billion years ago, our solar system was nothing more than a large cloud of gas and dust, not much different than the Orion Nebula (Messier 42) that we enjoy looking at with our backyard telescopes every winter.  Composed of mostly hydrogen, the cloud coalesced over millions and billions of years until a catalyst – most likely the shockwave from a nearby star exploding as a supernova – jolted the cloud into a spin and collapsing in on itself.  The dense center of the nebula became our sun, the cloud flattened into a disk, and clumps of gas further out spun up into the gas giants that dominate our outer solar system.  Scattered between these gas giants were pockets of primordial dust, left over from the very first stars and planets that populated our universe.  This dust collided and stuck together as it began to form larger and larger rocky bodies, eventually the size of small planets called planetesimals.  Dozens or possibly hundreds of these baby planets collided over hundreds of millions of years, forming the rocky planets of our solar system today, and scattering debris across the cosmos as asteroids and comets and moons.

From that initial shock that jolted our solar system into motion, everything continued to spin.  Throughout eons of chaos and disorder, the rotation of the planets and moons and asteroids and comets and even the sun itself persisted.  The flattened disk that was the nursery for the birth of planets maintained a consistent path through space, which today we call the ecliptic.  As viewed from Earth, the ecliptic is the superhighway on which the sun and planets travel across our sky.  Despite the violent early days of the solar system and the catastrophic collisions of protoplanets, none of the eight major planets ever strayed more than a few degrees from this original orbit.  As such, we can look out and quickly identify the planets wandering against the backdrop of static stars.  For this reason, the word planet comes from the Greek planetes meaning “wanderer”.

Early in the morning of June 3^rd these wanderers will come together for a relatively rare celestial alignment.  In the hour prior to the sun rise at 5:17AM, look to the East to see up to 6 planets followed closely by the Sun.  Starting to the Southeast, Saturn will shine brightly.  As you move down to the East you will pass Neptune under the belly of Pisces, Mars glowing red near the crescent moon, followed by Uranus then Jupiter peeking over the horizon.  Venus may be visible in the best observing situations, however Mercury will certainly be obscured by the rising Sun.

The planet Mercury is a unique specimen within our solar system.  Orbiting every 88 days, this closest rocky body to our Sun has no geological activity and virtually no atmosphere.  Its surface is pockmarked with testimonies of destruction, and with nothing to erode the signs of billions of years of impact events, making it a dense, grey, blemished world.  The ancients knew of Mercury, and many cultures named it relative to its proximity to the Sun and its quick movements across the sky.  Being so close to the Sun, Mercury is often not visible to terrestrial viewers, however on the morning of January 12^th Mercury will be 23.5 degrees from the Sun, its Greatest Western Elongation.  Look to the Eastern Horizon in the hour before sunrise to catch a view of this elusive wanderer.

On the evening of January 14^th, Saturn will make a close approach to the Moon in the constellation Aquarius.  To astrologers, this lunar conjunction with the ringed planet may impart a pragmatic and practical approach to financial stability, however, to astronomers it means a fun opportunity to observe the waning crescent moon next to the famous rings of Saturn.  Binoculars or a small telescope is all that you need for this event, with just 40x magnification to resolve the rings separate from the planet.  The waxing crescent phase is also a great time to look at the highlighted craters of the moon. Get out early this evening, as Saturn will begin to set in the Western hills around 8 PM.

Just a few nights later on the evening of January 18^th, Jupiter will make its close approach to the Moon in the constellation Aries.  A first quarter Moon will spend the evening with the King of Planets, and your binoculars or small backyard telescope should be able to resolve the four Galilean moons: Ganymede, Callisto, Europa, and Io.  Those last two, Europa and Io, will be having a conjunction of their own that night, passing extremely close to one another as viewed from Earth.  With larger scopes of 100mm or more, and the blessing of a clear night, you may be able to observe the red and white bands of clouds that circle the planet, as well as its most defining feature – the Great Red Spot.  Like a high-pressure hurricane, this storm averages 1.3x the diameter of Earth, with wind speeds up to 432 km/h or 268 mph.  If early astronomical observations were correctly recorded of the same storm, then it has been in existence since at least 1665.

If you happen to be around the Four Corners area on October 14^th, make sure to have your solar eclipse glasses with you.  After that day, you will be able to tell your friends that you saw an eclipse from four different states!  An annular solar eclipse will grace our skies that morning, with the full eclipse beginning around 9:30 MST and lasting for just under 5 minutes.  You may encounter this path of totality along a swath of the United States covering from the coast of Oregon to South Texas on that day.

An annular eclipse is a type of solar eclipse, where the moon is directly between the Earth and Sun.  When viewing a total solar eclipse, the moon will completely cover the disk of the sun, whereas an annular eclipse only covers the center of the Sun, leaving a slim ring of light visible around the Moon.  This halo is the annulus, from the Latin meaning “little ring”, and mathematically is defined as the area between two concentric circles.  This “little ring” is also where we get the word annual, for the circular nature of the yearly calendar.

The reason we have both total and annular eclipses is due to the non-circular nature of the universe.  Seemingly a contradiction to all of this talk of rings and circles, objects in space are governed by the forces of gravity, and orbit in ellipses rather than true circles.  At some points in the Moon’s orbit, it is closer to the Earth, at which time we experience Supermoons like we did in August.  This closest part of the Moon’s – or any other object’s – orbit is known as perigee.  At other times, the ovular orbit takes the orbiting body further from the primary body, and this more distant point is called apogee.  Likewise, when the moon is at apogee during a solar eclipse, the apparent diameter of the Moon as viewed from Earth is not sufficient to fully cover the Sun, giving us a “ring of fire” eclipse that is quite the sight to behold.

Whether total or annular, a solar eclipse happens about twice per year on Earth, though with more than 70% of Earth’s surface covered by water, they are not always visible from terra firma.  In addition, the rotation of the Earth means that these eclipses could happen on any continent, and so are unique events when able to be seen locally.  The path of the annular eclipse is around 120 miles wide in that track across the Western United States, however a viewer hundreds of miles away can still experience a partial eclipse.  Here in Central Yavapai County, we will see approximately 82% coverage of the Sun’s face over the course of the morning. 

AND DON’T FORGET YOUR SOLAR GLASSES FOR SAFE VIEWING!

From double full super moons to ringed giants at opposition, August was full of local events in our Solar System, whereas September takes us back to some amazing deep sky objects.  Many of the best clusters and nebulae lie along the galactic plane, easily identifiable in the sky as the Milky Way.  While one can technically define the Milky Way as everything around us, the vast swath painted across the night sky represents the edge-on view of much of our galaxy, given Earth’s position somewhat centrally located on what we call the Orion Arm of our barred spiral galaxy.  Being in the middle of all the action, looking toward this denser region of stars offers the casual viewer opportunities to pick out many more “faint fuzzies”. 

The constellation Sagittarius borders the Western edge of the Milky Way, pointing his bow and arrow into this hotbed of stellar activity.  Hundreds of stars inhabit this constellation, with 17 making up the primary outline of the centaur archer.  More easily identifiable are the 8 primary stars that make up the “Teapot” asterism, which defines the torso and bow of the Archer.  Within or abutting the Teapot are five Globular clusters, catalogued by Charles Messier as M22, M28, M54, M69 and M70.  The clusters of stars are only a few light years across yet are packed with thousands or even millions of stars orbiting the galactic center together.  To the naked eye, these may seem like a single star, then binoculars will show the observer a fuzzy cotton-ball like image, and larger telescopes will begin to resolve many of the individual members of these heavenly neighborhoods.  Use your binoculars or a wide-angle eyepiece on your telescope to scan the Teapot and see how many star clusters you can find.

The stellar life cycle may begin or end with a large cloud of gas and dust, either coalescing over millions of years into stars and planets, or inversely created when a star runs out of fuel and collapses in on itself, exploding in one of the universe’s greatest displays of light and energy.  These clouds are known as nebulae, Latin for “mist” or “fog”.  As you peruse the Teapot and Milky Way, areas of light and dark gas will highlight against the dark backdrop of space.  The Lagoon Nebula is visible to the naked eye in the darkest skies and is a perfect starting point for the amateur astronomer.  As an emission nebula, it has a pinkish hue created by the ionized particles coming off nearby stars.  Separately, the Trifid Nebula is a combination emission and reflection nebula, appearing both pink and blue as you scan the region.  Also containing an open star cluster, the Trifid Nebula is a late summer favorite among many astronomers.

So, remember to look to the South, for the teapot pouring out the milk, and you will be locked on to some of the greatest views in the Northern Hemisphere summer.

August hosts a plethora of lunar and planetary events, perfect for the Backyard Astronomer.  Even the most basic binoculars or telescope will allow one to enjoy our celestial neighbors as they put on quite the display this month.

August 1^st starts off the month with a Full Supermoon.  The second Supermoon this year, this event occurs when the Moon appears slightly larger in the sky due to its proximity to Earth in its elliptical orbit.  While there is no strict definition of a Supermoon, it is commonly accepted that the moon be within 90% of perigee, or the closest approach of its orbit to Earth.  By contrast, the furthest part of an elliptical orbit is called the apogee, and the Moon’s distance from Earth can sway from about 405,500 km to as close as 363,400 km, or about 252,000 miles to 225,000 miles.  This full moon was also known in the Great Lakes regions as the Sturgeon Moon, for its timing correlated with the preferred fishing season.

On August 10^th, Mercury will be at greatest Eastern elongation from the Sun, meaning it is as high in the evening sky as we can see it, before it begins to move back around the Sun.  “Eastern Elongation” may seem like a misnomer, referencing where the planets are in relation to each other, however you will look to the Western horizon just after sunset.  This is the best day of the year to catch a glimpse of the elusive owl whom the Maya regarded as a messenger to the underworld.

In the early hours between August 12^th-13^th the Earth will pass through the tail of comet Swift-Tuttle.  Having last visited the inner solar system in 1992, and not returning until 2126, the debris cloud of dust and ice particles affords the annual Perseids Meteor Shower, with excellent viewing this year as the moon will only be a crescent.  Enjoy this show after midnight when you may catch upwards of 60 meteors per hour.  

On August 24^th, the bright red head of the Scorpius will be eclipsed by the moon.  This rare event will see the occultation of Antares by the moon, disappearing behind the moon at 6:55 PM MST and reappearing an hour later at 7:55PM.

Saturn puts on a show on August 27^th, at what we call Opposition.  Saturn will be at its closets to Earth on this night, and fully illuminated by the Sun directly opposite it.  Moving through the constellation Aquarius in the Southern sky, a medium sized telescope will allow you to see the rings and maybe even its moon Titan.

Wrapping up the month of August on the evening of the 31^st is the second Supermoon of the month.  When two full moons occur in the same calendar month, we call the second one a Blue Moon.  This Moon won’t really appear blue but is a relatively rare event to have both full moons in a single month be Supermoons.