Two months in a row we are fortunate to have the largest of our Solar System’s Gas Giants put on a stunning display.  While in August Saturn was at opposition, Jupiter will also be at its nearest and brightest to Earth on the night of September 26^th.  Unlike the Saturnian opposition, however, when the Moon lit up the sky on August 14^th at 93% fullness, on that Monday night in September, backyard astronomers the world over will appreciate the darkness afforded by a New Moon.

Jupiter was the name given this planet by the ancient Romans in honor of their chief God.  This naming pattern follows the Grecian title of Zeus, the Babylonian designation of Marduk, the Sanskrit honorific of Brihaspati, the Hebrew epithet of Tsedek, and Nordic mythology of Thor, from which we still refer to a particular day of the week as “Thor’s-day” (Thursday).  Mùxīng as it is known in Chinese is so important in their mythology that the entirety of the zodiac revolves around the approximately 12-year cycle of Jupiter making a complete orbit of the Sun.

If one was able to take all of the “stuff” in the Solar System – excluding the Sun – and push it together into a giant ball, Jupiter would still be more than twice as large as everything else combined.  Even the smallest of telescopes and binoculars can pick out the 4 Galilean moons orbiting the planet, though with larger scopes one can begin to resolve many more, with 79 known moons orbiting this giant.  On clear nights, you may also start to notice colored bands across the surface of the planet.  These are clouds of gas, like jet streams on Earth, with different currents moving in different directions and in colors ranging from white to orange and brown.

The Juno spacecraft arrived in Jovian orbit in 2016 and has been studying the planet in detail ever since.  While your backyard observations will be in the visible light spectrum, Juno is able to study Jupiter’s gravitational field and magnetic field through microwave, infrared and ultraviolet astronomy.  In addition, the new James Webb Space Telescope has already gazed at Jupiter in the infrared, allowing scientists to merge data across light spectrum to understand more of how this giant planet formed and continues to evolve as the defender of our inner solar system today.

The planet Saturn has intrigued astronomers – both professional and amateur – since Galileo first sketched what he thought were two odd-shaped moons on either side of the planet.  His final telescope at magnification 30x was still not quite able to resolve the rings that we love so much to gaze at.  Dutch mathematician Christiaan Huygens explained the rings of Saturn by 1659 and identified its moon Titan with a slightly larger telescope at 43x magnification.  Both major accomplishments for their time, we now benefit from even the most basic telescopes and binoculars able to show us the beautiful rings of Saturn and its moon Titan nearly any time of year.

Saturn is the second largest of our solar system’s gas giants behind Jupiter, with a volume 763 times that of Earth.  Despite its massive size, the average density is less than that of water, and as such is only 95 times more massive than the Earth.

In August, the planets align to give the best view of the year of this exceptional viewing opportunity.  Saturn reaches opposition on August 14^th, meaning it is the closest to Earth, and also its brightest due to the Earthward facing side fully illuminated by the Sun.  It will be one of the brightest objects in the sky this month, moving Westward along the ecliptic, the path that all planets take across the Southern sky.  You can find it near the tail of the constellation Capricornus that night.

At opposition, Saturn will be approximately 816 million miles away, a distance that takes light 73 minutes to traverse.  So, when you are gazing at the Ringed Planet, you are actually seeing light that left the Sun, travelled 1 hour 21 minutes to Saturn, and then back 1 hour 13 minutes to your eyepiece in Northern Arizona.  Those same particles of light may have taken upwards of a million years to escape the 430,000 miles of the Sun’s dense plasma, but we will discuss that in more detail another day.  If your telescope mirror is at least 2” or larger, you should also be able to see Titan off to the side, with the rings nearly making a line pointing to this moon that is larger than the planet Mercury.  Titan’s dense methane atmosphere often makes it appear slightly orange.

The new James Webb Space Telescope will be photographing the planets outward from the orbit of Mars over the next few months and years and is sure to amaze.  In the meantime, if you are able to get a picture of Saturn through your telescope, share it with us on social media!

In the early summer months, the constellation Boötes moves to the western sky.  Adjacent the Big Dipper, some Ancient Greek Mythology tells of how Boötes invented the plough and was rewarded with a place in the heavens for this history-altering advancement.  Keeping in line with feeding the masses, the Yup’ik language – second most widely spoken Native American language after Navajo – of the Eskimo-Aleut people refers to this same grouping of stars as Taluyaq, literally translated as “fish-trap” for the funnel shape of the stars.  Many different Chinese constellations have focused around Arcturus, the brightest star in Boötes and in the Northern hemisphere, which was so important in their mythology that it’s position in the sky marked the beginning of the lunar calendar.

Boötes is home to a plethora of deep sky objects, many of which represent the earliest discoveries after the invention of the telescope.  The easiest star to locate first is the bright orange-giant Arcturus.  Just under 37 light years distant, 25 times larger than our sun and 170 times as luminous, it should be a quick task.  The next brightest star is Izar, which viewed with a scope of diameter 3” or larger reveals a beautiful multi-colored double star.  Approximately the same distance but in the opposite direction of Izar is magnitude 11 galaxy Caldwell 45.  Six degrees to the Southeast of Arcturus is Pi Bootis, another double star visible to the naked eye.  Remember, you can easily approximate degrees in the sky with your hand at arm’s length – a fingertip is about 1 degree, three fingers about 5 degrees, and a clenched fist is about 10 degrees.

The early solar system was a violent place.  We know this courtesy of modern telescopes and models generated by today’s supercomputers, allowing us to peer at clouds of gas around distant stars, and observe their planets forming, and hypothesize how our solar system would have formed under similar conditions.  Like the rings around Saturn, a young star usually forms in a cloud of tenuous gas, slowly pushing inward and becoming more and more dense, with the star at the center hosting the majority of the mass – and therefore gravity – and the outer rings coalescing into planets, moons, asteroids and comets.  Over time, these objects run into each other, as we observed with objects hitting Jupiter over the past few decades, and large craters on the surface of Earth and elsewhere about the solar system preserved as monuments to these cataclysmic events.

It is believed the Sun absorbed enough material to initiate nuclear fusion around 4.6 billion years ago.  Over the next 100 million years, the disk of gas around it formed all the planets we now know, as well as many others that are long since forgotten.  Theia was one of these protoplanets, about the size of Mars, having formed much further out in the solar system with the comets, and containing much more water ice than the inner planets. Its orbit was erratic, or possibly disturbed by the passing of a wayward star, and after countless close encounters, Earth and Theia collided in what must have been an awesome event.  The violent impact knocked Earth sideways, merged the heavy planetary cores into a much larger core and mantle, ejected debris for hundreds of thousands of miles into a new orbit around the Earth, and everything began a slow process of cooling to form continents and oceans, and even our moon.

Many other bodies experienced this same type of event, as we can see the tilt and rotation of every planet in our solar system slightly different from the others.  Jupiter being the largest was able to better withstand impacts than the smaller, rocky planets, and only has a tilt of 3°, while Venus was somehow knocked completely upside down to a 177° tilt and rotating in the opposite direction of the other planets.  Uranus lies at a 98° tilt relative to the sun and essentially orbits on its side, while Earth, Mars, Saturn, and Neptune all have relatively stable seasons due to their axial tilt – Earth at 23.5°, Mars at 25°, Saturn at 27°, and Neptune at 30°.

The 23.5° tilt of Earth’s axis through the poles allows different parts of the Earth to lean toward or away from the Sun at different times of the year.  As we orbit the Sun, the northern Hemisphere gets closer and more direct sunlight, culminating on June 21^st this year, which we celebrate as the Summer Solstice.  The sun will appear to stand still in the sky for three days as it reaches its northernmost view of Earth, and then will begin to move southward again for the next 6 months.  This change in the seasons affects all of Earth’s weather patterns and the evolutionary habits of plants and animals alike.

And it’s all thanks to Theia.

The Earth has been estimated at a total mass of approximately 5.9722×10²⁴ kg, or more commonly notated as 1 Earth Mass (M_E).  One Solar Mass – or the Mass of the Sun and notated as M_☉ – is approximately 333,000 Earth masses.  The whole of the solar system is estimated at 1.0014 Solar masses, meaning all the planets, moons, asteroids, and comets make up just 0.0014 the mass of the Sun.  This all adds up to a lot of stuff floating around in our celestial backyard.

Us Earthlings, however, love to produce trash.  We have spent vast amounts of time and energy converting earthly resources into products that ultimately lose value and become garbage, that is subsequently dumped on land and in water, since well before recorded history.  Some of the greatest archaeological discoveries of our past come from ancient landfills and latrines.  So, it is no surprise that our forays off our planet have also produced large quantities of waste.

Beginning on October 4^th, 1957, Sputnik 1 launched aboard a modified Russian ICBM to become the first artificial satellite in space.  Its orbit decayed over the coming weeks and fell back to Earth on January 4^th, 1958, burning up in the atmosphere on in its way in.  March 17^th of the same year saw the United States launch the 3.2kg Vanguard 1 satellite, which still orbits the Earth today, along with the 31kg upper stage of its launch vehicle.  Some 64 years later, the US Space Surveillance Network tracks around 20,000 artificial objects orbiting the Earth, with only 2,218 of those being operational satellites.  Those are the most recent numbers from 2019, and with the rise of private space industry giants like SpaceX and Blue Origin, and more countries entering the space race every year, those numbers are growing faster than ever.  But these are just the numbers of objects large enough to be tracked from ground-based observatories – like the Navy Precision Optical Interferometer outside Flagstaff, Arizona, which can track objects the size of a quarter.  Accounting for even the smallest paint flecks, estimates place the total number upwards of 130,000,000 objects, made by humans, and still flying around the Earth at ungodly speeds.

“Space junk” is the colloquial term for all this debris, and generally carries a negative connotation.  The International Space Station was recently forced to adjust its orbit and shield the resident scientists in their respective escape capsules when Russia tested a space weapon that destroyed a defunct satellite and created hundreds of thousands of small pieces of debris.  Even the smallest piece of metal shaving orbiting at around 15,700 miles per hour could easily pierce through the outer layers of something like the ISS, causing depressurization, major repairs, or loss of life.

Despite these astounding numbers, we know that space is a BIG place.  Collisions are not common occurrences, even with billions and trillions of micro-meteoroids scattered across the solar system.  Impact craters on Earth, the Moon, Mars, and elsewhere about the Solar System tell us that major impacts do happen with relative frequency in the space timeline, but our technology is just advancing to the capability of capturing such events.  Two such events have been documented, and both were with Jupiter.  Astronomers everywhere watched as Comet Shoemaker-Levy 9 flew its Icarus like path and was torn apart by the immense gravity of Jupiter, crashing into, and leaving a trail of temporary scars in the Jovian atmosphere in July 1994.  By comparison, on September 13^th, 2021, a handful of amateur astronomers just happened to be photographing Jupiter when a bright flash appeared, estimated to have been caused by an asteroid around 300 ft in diameter.

As we develop new ways of tracking objects across space, such as by Greg Leonard and the team at the Catalina Sky Survey in Tucson, Arizona, more advance notice of impacts will follow.  Many professional observatories are dedicating their clear nights to hunting for unknown comets and asteroids, while amateur astronomers are leading the charge in following the larger objects we have placed in uncontrolled and forgotten orbits.  A SpaceX Falcon 9 booster that launched a weather satellite in 2015 was recently tracked by amateur astronomers to find that it will impact the far side of the Moon on March 4^th.  The first known unintentional collision of a human made object with the Moon, the 3.6-ton rocket is expected to meet its fate around 12:26 UTC.  These calculations by amateur astronomers have allowed international space agencies to adjust the orbits of lunar satellites which may be in the way or – or may be able to witness this impact.

Sadly, being the impact will be on the far side of the Moon, we will not be able to observe it with our backyard telescopes.  But with record numbers of orbital flights increasing year over year, I’m sure we will get more opportunities to witness collisions in space.

And just maybe in a few thousand years, space archaeologists will look to all these defunct satellites, rocket bodies, landers, rovers, and nuts and bolts to catalog the many long forgotten adventures of our current era.  Or maybe it will just be another pile of orbiting space junk to dodge on our way to colonize the stars.

Author’s note: With the above-described size of space, and the amount of stuff out there, our understanding of objects and orbits increases day-over-day.  Since the writing of this article, it has been hypothesized that the booster may be a Chinese Chang’e 5 booster instead of the originally reported SpaceX booster.  This has been disputed by the Chinese government, and at this point we just don’t know whose rocket it is.  As it gets closer to the moon, it is possible that the international fleet of satellites may properly identify it, and it’s just as possible that we may never know for sure.  Either way, we are in for a scientific treat on March 4^th.

In 1609 Galileo pointed his rudimentary telescope at the heavens, finding three, and then four moons orbiting Jupiter.  He combined two polished glass lenses, slightly convex at different angles, and was able to magnify the image he gazed at.  This wasn’t a new technology, but a basic monocular had been used for mostly terrestrial purposes, allowing humans to peer across valleys and mountaintops, or at their military foes from great distances.

This type of magnifying device is known as a refractor scope, for the way it bends or refracts the light as it passes through the lens.  The total light gathered across the surface is then bent to converge on a single point, with this distance from the lens to the converge point known as the focal length.  By combining two lenses of different focal lengths at either end of a tube it was discovered that the image one looked at could be greatly magnified.

The technology of polishing lenses exploded, with royalty hiring glass makers to design bigger and better lenses for government sanctioned observatories and royal astronomers. However, as the lenses got bigger, the refracting process of light became more complicated.  Just like a child’s toy prism – or the cover of a Pink Floyd album – the light we see enter the glass is divided into different colors as the various wavelengths of light are slowed at different speeds while passing through the dense medium of the glass.  When this happens, a telescope can have an effect called chromatic aberration where the colors at the eyepiece don’t match up quite right and the image looks fuzzy.  The other problem was that as lenses got bigger, the glass became very heavy, and can only be supported from the thin edge of the lens so as not to obstruct the light passing through it.  And as the lenses got bigger, so did the tube, with the largest

To this end, a little-known polymath named Isaac Newton came up with a different type of magnification process in 1668, using a concave mirror to reflect instead of refracting the light back to the observer’s eye.  A secondary mirror placed above the mirror sends the light out the side of the telescope.  This solved all the main problems of the refractor, being the light was not divided into different wavelengths through the lens, the mirror could be fully supported on the back and therefore much stronger, and the light reflected back up through the tube and out at an angle allowed the tube to essentially be used twice, greatly reducing the long tubes of refracting telescopes to achieve the same focal length.

At present, some of the largest refracting telescopes have been used for great discoveries, such as the 24-inch telescope at Lowell Observatory which discovered the red shift of galaxies and mapped the moon for the Apollo missions.  Reflectors on the other hand have gotten much MUCH larger, including many across Arizona like the Discovery Telescope in Happy Jack with its 4-meter primary mirror.  This is also the format commonly used for the great space telescopes, with the James Webb Space Telescope’s 18 gold hexagon mirrors unfolding in early January 2022 to a completed primary mirror size of 6.5 meters.

So, which is best for you?  Well, it depends on what you want to do.  Many of the images we have featured in this article over the years have been from Joel Cohen who has a 7-inch refractor he uses for astrophotography.  My personal telescope is a type of reflector called a Dobsonian, which is great for viewing but less so for astrophotography.  Whichever route you choose to go, I wish you clear skies!

As early as 1923, space telescopes were proposed to peer deeper into the universe, without the obstruction of the Earth’s tenuous atmosphere.  By the 1970s congress had funded the first of these great space telescopes, with the 2.4 meter primary mirror completed in 1981 for a Ritchey-Chreitien Cassegrain type telescope which finally launched in 1990 in the cargo bay of the Space Shuttle Discovery, carrying the name Hubble. A few servicing missions later, the Hubble Space Telescope has been gracing our computer screensavers with images of the cosmos for over 31 years.

Before it’s launch, however, NASA knew that the narrow visible spectrum that Hubble was designed to observe in was not the end-all goal of space telescopes.  A series of additional orbiting laboratories able to capture light from all ends of the spectrum were developed, including the Chandra X-Ray Telescope, the Spitzer Space Telescope in the infrared, and the Kepler planet hunter telescope, but NASA engineers and astronomers dreamed of something bigger and better.  In 1989, the concept was floated for a much, MUCH larger space telescope that could open like an umbrella, with multiple mirrors converging to create a 4-meter aperture telescope that could image across a much larger swath of the visible to near infrared spectrum.  The next three decades of scientific advancements, engineering marvels, as well as numerous delays and drastic budget overruns have led up to this moment. 

On December 25^th the James Webb Space Telescope will launch aboard an Ariane 5 rocket from the European Space Agency spaceport in French Guyana, South America at 5:20 AM MST.  Whereas Hubble orbits at about 330 miles above the Earth, making it a previously accessible target for repair and upgrade mission with the now retired fleet of Space Shuttles, The JWST will orbit the Sun at what is known as the L2 Lagrange point.  This is a unique point in space where the gravitation forces of the Sun and Earth balance each other and create a stable point in space for an object to remain in relative equilibrium.  There are 5 such Lagarange points created by the Sun/Earth gravity wells, with the benefit of the L2 point being that it will always be in a line with the Earth directly between it and the Sun, helping to block the Sun’s light – and astronomers like it dark!  The JWST will take approximately a month to reach this point 1.5M km from earth, about 3 times further than the moon.  During this time, the observatory will open its mirrors, solar panels, and a unique solar shield that will add additional protection from the light and heat of the sun, allowing for more detailed observations in the near and mid-infrared.

20 countries, more than 30 years, 9.7 billion dollars, and human capital that could never be accurately calculated, will all culminate in a Christmas gift to the world early this Saturday morning.  God speed James Webb!

The dormant volcano Mauna Kea is the highest point in the Central Pacific and of the Hawaiian Islands. At such a height, the benefits of dry air above the clouds with little to no light pollution make it the preeminent site in the world for astronomical observing. As such, many large telescopes operate at its summit. One of these is the Subaru telescope of the National Astronomical Observatory of Japan.

Subaru, you say? They sold naming rights of a telescope to a car company? Well, no. The car company and the telescope were both named for the open star cluster Subaru which graces the fall and winter skies of the Northern Hemisphere. The closest naked eye star cluster to Earth, the six bright stars of Subaru glow hot blue and are surrounded by beautiful nebulosity that can be seen with even the smallest binoculars or telescopes. This cluster has been clearly recorded in dozens of ancient cultures and even referenced in the bible. The oldest known depiction of the night sky is a bronze disc found in Germany that dates to around 1600 BCE and is believed to include the sun, moon, and the stars of the Subaru cluster.

Fast forward to 1953, when the Japanese businessman Kenji Kita combined six smaller companies across the manufacturing sector to create Fuji Heavy Industries, producing everything from scooters to cars to busses. Drawing from his love of the sky to constitute the combined six businesses he brought together, he named his first car the “Subaru 1500” with the logo a clear representation of the star cluster. Whoa, whoa, whoa. The brightest and best star cluster, most visible to the naked eye, with visible nebulosity, and you’ve never heard of it? That may be because Western culture traditionally uses ancient Greek and Roman names for the primary constellations, and we know “Subaru” as “The Pleiades”.

When Billy Bob Thorton’s character approaches Bruce Willis, Ben Affleck and Steve Buscemi to save the world from impending doom in 1998’s blockbuster film “Armageddon” they only had 18 days to prevent an asteroid the size of Texas from annihilating life on Earth. In the years since, real NASA scientists have spent countless hours observing NEO’s – Near Earth Object’s – and painstakingly tracking their past and future orbits to find which will be the next major asteroid to cross path’s with Earth. And while we are yet to find one that with certainty will be the next major Chelyabinsk or Tunguska Event, that hasn’t stopped researchers from thinking about ways to prevent such a collision from happening.

Since 2018, a joint planetary defense operation between NASA, Johns Hopkins Applied Physics Laboratory, and the space agencies of Europe, Italy, and Japan have come together to design the DART Mission. The “Double Asteroid Redirection Test” is scheduled to launch from Vandenburg Air Force Base in California at 11:20 PM MST Tuesday 23 November aboard a SpaceX Falcon 9 rocket for its one-way trip to the binary asteroid Didymos. While Didymos is not a threat to Earth, it was chosen as the perfect testing ground for a potential new technology that could be used for future asteroid redirect missions.

On 2 October 2022 the DART spacecraft will collide with the smaller of the two asteroids in the Didymos binary system. Unlike most spacecraft full of scientific experiments, the primary craft is essentially a 500kg (1,100 lb) inert mass with little more than a guidance system and antenna powered by a small solar array. A few days prior to impact a small CubeSat designed by the Italian Space Agency will seaparte form the main spacecraft and trail behind to image the impact and relay both narrow and wide field images back to Earth.

The plan is such that the impact will have a very small effect on the asteroid at the moment of collision, just a half a millimeter per second. That is enough change however that as Didymos continues its trek around the sun, Earth based telescope will be able to see how its orbit changes. This information will help us plan future missions to move asteroids of varying sizes out of orbits that may be deemed hazardous to Earth or other potential risks. A follow up mission is scheduled to revisit Didymos 5 years after the impactor to study its geology and the longer term affects of the initial mission.

Here’s to hoping it works and we don’t have to sacrifice Ben Affleck again.

We live on Earth, which orbits the sun every 365.256 days as part of our Solar System.  Our Solar system is one of hundreds of millions of stars and similar systems that orbits the center of our Milky Way galaxy about every 225 million years.  We are familiar with the cloudy or “milky” swath above our heads that is visible on moonless nights throughout much of the year.  With advancements in radio astronomy in recent decades, we have been able to peer deeper into the sky and analyze the structure of our galaxy to learn we are on the outskirts of an arm in a giant spiral galaxy, held together by the gravitational pull of dark matter and a massive black hole in the center which we call Sagittarius A* – pronounced “Sagittarius A Star”.

For hundreds of years, we had to guess what the structure of our galaxy was, as we are inside of it and cannot see it from an outside perspective.  Our best approximation came from looking at our neighboring galaxies, some of which are visible to the naked eye.  Our nearest partner in space is the Andromeda galaxy.  Although it hangs out about 2.5 million light years distant, it is large enough and bright enough to have been documented over a thousand years ago – long before the advent of the telescope.  In the tenth century Persian astronomer Abd al-Rahman al-Sufi described Andromeda as a “nebulous smear”, with later astronomers using rudimentary telescopes to define the blurry spot in the sky as an “island universe”.  With a diameter more than 6 times that of the full moon, Andromeda is one of the largest objects that astronomers can see with either the naked eye or simple ground-based equipment, and many astronomers have spent their lives dedicated to researching it.  However, it was not until Edwin Hubble studied Andromeda in 1925 that we truly understood it was a separate galaxy at such as distance from our own.  This realization expanded our understanding of the universe from essentially believing in one galaxy to now knowing there are upwards of two trillion separate galaxies in the observable universe.

October is arguably the best month to view Andromeda in the evening sky, reaching the zenith (directly above you) around midnight.  October 6^th is the new moon, and about an hour after sunset that evening Andromeda will be approximately 30° above the Northeast horizon.  You can find it by looking for the Great Square of Pegasus – an easily identifiable asterism – with the bright double star Alpheratz forming the northern corner.  Two streams of stars seem to pour left from this point, and about 12° from Alpheratz (slightly more than the size of your fist held at arm’s length) and just above the top line of stars will have you looking at a cloudy patch of sky.  Bust out the binoculars and you will see this is Andromeda, and then with the telescope you will begin to resolve the bright galactic center and swirls of stars around it.  You will see Andromeda just slightly off from edge on, so it should look like a long oval getting brighter and denser towards the center.