I joined the Barnard-Seyfert astronomy club in Nashville. E. E. Barnard was from Nashville. He was a great observer and photographed the Milky Way. Carl Seyfert was instrumental in building Dyer Observatory.
I attended a meeting in July, 2008. The club president gave a presentation showing the location of Messier objects. There was discussion about star parties.
I looked forward to the Messier Marathon. The object was to observe as many of Charles Messier's 110 objects as possible.
It was a long road from interpreting events in astronomy as whims of gods and goddesses to explaining them as the interaction of natural forces. The sun, moon & planets are part of nature as are mountains, forests & seas. The ancient Greeks made inroads into science. Aristarchus of Samos knew that the earth circled the sun 18 centuries before Copernicus.
In astronomy, things are often not what they seem. There are apparent motions, apparent magnitudes & apparent diameters. Our senses say that the sun rises in the morning and sets at night. This is not true! The earth is rotating. We are the ones moving. Moreover, we may think that Venus is brighter than the stars because it appears so when in reality this nearby planet merely reflects light from the sun. The stars are enormous suns trillions of miles away emitting their own radiation. Finally, we hold our thumbs up to cover the moon, and its diameter seems hardly an inch. We know this is false, to which the astronauts who walked on the moon will attest. Our sensory perceptions evolved on earth to ensure our survival and our ability to function in immediate surroundings. Knowledge of our planet's place in the solar system and the solar system's place in the Milky Way came slowly over centuries through the collaborative efforts of geniuses.
The sun is the source of Earth's energy. Without the sun, life on earth would cease. Early civilizations knew its importance. They worshiped the sun! People in high latitudes such as Scandinavians appreciate its annual return.
The sun is a star, one of 400 billion in the Milky Way galaxy. It seems different from other stars because it is close. We circle it. The sun is yellow and 93 million miles away. Other stars appear as points of light because they are trillions of miles away.
The sun does not rise and set. The spinning earth makes it appear so. The apparent path of the sun over the course of a year is called the ecliptic because it is where eclipses take place. The ecliptic is in the center of the Zodiac.
The sun formed when a cloud of hydrogen gas collapsed. Its core was squeezed so tight that nuclear fusion began. Hydrogen atoms combined to form helium and give off energy. The sun shines by nuclear energy, some of which takes the form of visible light.
In time, the sun will exhaust its hydrogen. It will burn helium to form other elements. Toward the end of its cycle, the sun will become a red giant. Its outer shell will expand, and its core will shrink. Its core will become a white dwarf and eventually a burned-out ember. The heaviest elements are created when massive stars explode as supernovas. Elements fly into space.
The 5 major circles of latitude are the Arctic Circle, Tropic of Cancer, Equator, Tropic of Capricorn & the Antarctic Circle. The Tropic of Cancer runs off the southern tip of Florida. The Tropic of Capricorn runs through Australia. The area between the Tropics of Cancer and Capricorn is called the tropics. The word comes from the Greek "tropos," meaning turn because the sun appears to turn and move in the other direction after being overhead at these places. The apparent movement north and south by the sun during the course of a year is caused by a 23 1/2 degree tilt of Earth's axis to the plane of its orbit.
The hottest days come after the first day of summer and the coldest days come after the first day of winter because it takes time for the earth to heat up and cool down.
Earth's rotation causes day and night. The earth rotates 1000 miles an hour at the equator. Earth's revolution causes the seasons. The earth revolves around the sun 67,000 miles an hour.
It is easy to see why the ancients thought the stars rose in the east and set in the west. It is an illusion caused by our spinning planet. Stars appear 4 minutes earlier each night and disappear 4 minutes earlier as the earth orbits the sun.
There are 5 oceans: Atlantic, Pacific, Indian, Arctic & Southern. 70% of the earth is covered by water. 10% of the land is covered by ice.
Life began in the oceans, and our bodies are 75% water. We need it to live. Plants came onto the land 400 million years ago. They give off oxygen, making animal and human life possible.
The Perseids are the most reliable meteors. The Leonids are also important. Leonids have been known to be spectacular. They peak November 17. "Id" means from.
The Leonids of 1833 are legendary. An estimated 100,000 meteors fell per hour. It was a meteor storm! The superstitious believed it was the end of the world.
Bright meteors leave trails! Objects as small as apple seeds flare up because their temperatures reach 4000 degrees. Being seen against dark skies exaggerates their brightness. Meteors coming toward us appear as stationary bursts of light.
PERSEID METEOR SHOWER
I became aware of the Perseid meteor shower in 1961. In 1964, the Perseids were spectacular! I counted 351 meteors the night of August 11 and morning of August 12. Many were fireballs, leaving trails. I dreamed I would one day experience another shower like that. Most years it was either cloudy or the moon was up. I counted over a hundred meteors from my front yard in Lebanon, Tennessee, in 1978. As the years went on, the problem became one of getting away from lights, finding skies dark enough to make it worthwhile.
Meteors appear 50 to 100 miles up. Most are no larger than grains of sand. They enter our atmosphere at 40 miles per second. Nearly all are vaporized. The radiant for the Perseids is near the top of Perseus' head.
I do not see a man in the moon. I see a foot with 3 toes. The arch is the Sea of Tranquillity. The heel is the Sea of Serenity. The toes are the Seas of Crises, Fertility & Nectar.
The dark areas on the the moon are solidified lava. Lava seeped from the moon's interior and covered the lowlands. The bright highlands are covered with craters.
There are fewer maria on the moon's far side because the crust is thicker. The crust on the near side was weakened by Earth's gravity. The Russians photographed the far side.
I stood outside my apartment at the Village at Vanderbilt looking at a full moon through binoculars. What I noticed was the foot with 3 toes and how the lava plains contrasted with the brightness of the southern highlands. The maria are dark because iron-rich lava reflects less sunlight. I observed Tycho and the Y formed by Copernicus, Aristarchus, Kepler & Grimaldi.
The moon is tidally locked by Earth's gravity. It rotates once as it orbits, keeping the same side toward us. The moon orbits from west to east, rising 50 minutes later each night. It is visible less than half the time.
A full moon rises in the east at sunset and sets in the west at sunrise. I recall a full moon rising above the orchard on Aiken Road. A full moon is the only phase seen all night.
The sun's rays hit a full moon directly. There are no shadows. Lunar features are best seen along the terminator at first and last quarters when there are shadows. The terminator is the line dividing day and night.
Crescent shapes are common in the universe. The moon appears as a crescent when it is closer to the sun than we are. A 2-day-old crescent is easy to spot. Thin crescents are illuminated by a nearly full earth. Earthshine dims as the moon waxes.
The moon was created when a planet-size object impacted Earth in the early period of the solar system. Part of the earth was knocked out and eventually became the moon. The impact caused the earth to tilt 23 1/2 degrees on its axis. Earth's axis is an imaginary line running through the poles.
The ancients called the planets "wanderers" because they moved among the stars. They identified the wanderers with gods and goddesses. Jupiter was named after the king of the gods. Mars was named after the god of war. Venus was named after the goddess of love. The more observant noticed that the planets, sun & moon stayed inside a narrow band of constellations. It was called the Zodiac (zoo) because it was comprised of animals.
Of course, the planets are not gods and goddesses. Nor are they simply lights in the sky. They are places, worlds like and unlike our own. We talk of planets being in constellations, knowing it is another illusion. When we say a planet is in a constellation, what we mean is that it is in the direction of a constellation. That the planets, sun & moon stay inside the Zodiac demonstrates the flatness of the solar system. Its parts are in the same plane.
My cousin got his reflector out, and we observed Jupiter, Saturn, Mars & the first quarter moon. We had a nice view of the moon's craters in the southern highlands. We saw central peaks. Saturn and Mars were in conjunction, 2 degrees apart. Saturn was the brightest, and we saw its rings. I recalled how Galileo described them as "handles." We saw 3 of Jupiter's Galilean moons. The 4th was either in front of or behind the planet. We located the summer triangle, and I mentioned how massive Deneb is. Its absolute brightness is the greatest of all first magnitude stars.
From the Wal-Mart parking lot in Lebanon, I used binoculars to view an alignment of Saturn, Mars & Regulus near a 4-day-old moon. I observed earthshine, that ghostly light reflected from Earth to the moon and back to Earth. The drama took place in the constellation Leo after sunset. Saturn, Mars & Regulus lined up like Orion's belt.
Mercury circles the sun in 88 days, flitting back and forth from our western sky at sunset to our eastern sky at dawn.
Venus is the evening star 9 months and the morning star 9 months. Venus transited the sun in June, 2012, a black dot moving across the sun's disk.
Mars circles the sun in 697 days, less than 2 Earth years. It is closest when it is at opposition, on the opposite side of us from the sun.
The Curiosity rover landed on Mars in August, 2012. The public will not become excited until a man walks on Mars or fossils are discovered.
Jupiter is made of hydrogen and helium. It has no surface. When we view Jupiter, we are looking at cloud tops. Jupiter's rapid rotation has stretched its clouds into parallel bands. Dark bands are called belts. Light bands are called zones.
The Great Red Spot is shrinking. It is a storm, and all storms play out. The Red Spot has the characteristics of a hurricane, strong winds and circular motion. It has lasted because there is no land to slow it down.
Jupiter circles the Zodiac in 12 years. It was in Sagittarius in June, 2008.
Saturn is also made of hydrogen and helium. Yellow and gold bands comprise its atmosphere. The Hubble Space Telescope imaged Saturn's northern and southern lights. Titan is Saturn's best known moon and the second largest in the solar system after Ganymede. Saturn takes 29 years to circle the sun.
Uranus circles the sun in 84 years. William Herschel named Uranus' moons after Shakespeare's characters: Oberon, Titania & Puck from A Midsummer Night's Dream; Prospero, his daughter Miranda, Ariel & Caliban from The Tempest.
Neptune circles the sky in 146 years. We seldom hear of Johann Galle, the German who discovered it.
I defended Pluto for a while. Now, I think it is a Kuiper Belt Object. Pluto crossing Neptune's orbit casts suspicion on its status as a planet. Clyde Tombaugh discovered Pluto in 1930.
Pluto was the last planet to be explored. The New Horizons spacecraft reached Pluto in July, 2015, completing a 3 billion mile journey. Powered by nuclear energy, New Horizons headed for the Kuiper Belt
Pluto takes 248 years to circle the sun. Like Uranus, Pluto rotates on its side.
That Pluto has 5 companions supports the idea that it is a planet. Pluto was the god of the underworld. Charon ferried the dead across the river Styx. Nix was the goddess of night.
Stars rise 4 minutes earlier each night because the earth revolves around the sun. After a year, the stars are back where they began.
Changes in longitude do not affect how we see the sky. Changes in latitude affect it dramatically. Flying from Sydney to Santiago, the sky looks the same. Flying from Sydney to Reykjavik, there are big differences.
If we were at the equator, we would see all the stars in a year. If we were at the North Pole, Polaris would be overhead and we would see only the north circumpolar stars. They would circle the sky, neither rising nor setting. At the South Pole, we would see only the south circumpolar stars. If the earth were transparent, we would see stars in all directions.
There are 88 constellations, the number of keys on a piano. Western civilization inherited the constellations from the Greeks and Romans. Some look like what they are supposed to be. Others do not. The Big Dipper looks like a dipper. As part of Ursa Major, it is circumpolar, meaning it is close enough to the north celestial pole to neither rise nor set at mid-northern latitudes. It can be seen all night. The Dipper is an asterism, a well-known group of stars that is not a constellation. Orion's Belt and the Summer Triangle are asterisms.
Constellations are not real. They are imaginary star patterns created by farmers, shepherds & poets. Farmers relied on the stars to know when to plant and harvest crops. Shepherds watched the night sky as they tended their flocks. Poets invented stories about gods and heroes that have passed through generations. The Greeks gave us the 48 classical constellations. 40 more were added by European explorers. Frenchman Nicolas Lacaille added 17 while in South Africa. The International Astronomical Union divided the entire sky into 88 sections, adhering to classical boundaries. Every object in the sky is part of a constellation.
The end stars in the bowl of the Big Dipper point to Polaris, the North Star. Polaris is still inching closer to true north, the point directly above Earth's axis. Polaris was not always the North Star and will not always be. Thuban was the North Star 4500 years ago. 13,000 years in the future, it will be Vega. Precession of the equinoxes causes the shift. Over 26,000 years, the earth wobbles like a top.
The constellation Draco winds between the Dippers. Draco was the dragon killed by Hercules when he took apples from the Garden of the Hesperides. The Hesperides were nymphs who tended the garden.
The story of Hercules is in the stars. We see the Nemean lion (Leo), vanquished by Hercules as one of his 12 labors. He strangled the lion with his bare hands. Constellations in general depict man's conquest of the animal world.
The handle of the Big Dipper curves toward Arcturus. Orange Arcturus is in Bootes the herdsman and is the 4th brightest star. Bootes is accompanied by Canes Venatici, hunting dogs which chase the bears around the pole. The Whirlpool Galaxy (M51) is in Canes Venatici.
Spica is the first magnitude star in Virgo the virgin. Spica is found by extending the curve of the Dipper's handle through Arcturus. Spica is one of 4 bright stars occulted by the sun and moon because of their proximity to the ecliptic. Aldebaran, Antares & Regulus are the others.
Virgo is associated with the earth goddess Demeter and her daughter Persephone. When Persephone was abducted by Pluto and taken to the Underworld, Zeus brokered a deal whereby Persephone would spend summers with her mother and winters with her husband. This was how the Greeks explained the seasons.
The Virgo supercluster is called the Realm of the Galaxies. When we look in its direction, we look away from the plane of the Milky Way, out the top of our galaxy.
In Greek mythology, the Pleiades were 7 sisters. Orion the hunter chased them across the sky. When Orion bonded with Artemis, her brother Apollo grew jealous and sent a scorpion to kill him. That is why Orion and Scorpius are not in the sky at the same time, at least not in the Northern Hemisphere. I saw them both while in Australia.
Some people see 7 Pleiads. Others see 6. One story named Merope as the Lost Pleiad. She married a mortal and hid. The Pleiades are in Taurus the bull. Star lore is fascinating even though it is about man's imagination rather than science.
The Hyades, an open cluster in Taurus, were half-sisters of the Pleiades. This V-shaped star cluster is way beyond Aldebaran.
Auriga the charioteer carries a goat and 2 kids (small goats). Capella is the 6th brightest star.
Scorpius is a constellation that looks like what it is supposed to be. From my parents' front yard, I watched it crawl silently across the sky, moving low on the horizon. First magnitude Antares is like Betelgeuse in that it is a red giant and near death.
Libra the scales is the only non-living constellation in the Zodiac, although it was once the scorpion's claws.
Sagittarius the archer killed the scorpion to avenge Orion. Sagittarius resembles a teapot, and star clouds rise from its spout like steam. The Trifid Nebula is in Sagittarius. Dust lanes divide it into 3 lobes. Stars cause the hydrogen to glow.
The Orion Nebula is a stellar nursery. Stars are forming from gas and dust. The Horsehead Nebula is below Alnitak, the first star in the belt. The Horsehead is a dark nebula seen in silhouette because Alnitak lights up the gas behind.
Constellations fit together to create scenes. Orion's dogs, Canis Major and Minor, chase Lepus the hare. Sirius is the brightest star because it is close, only 9 light-years away. Sirius is blue and shines at -1.44 magnitude. Blue stars are young and hot. Canopus, the second brightest star, is dimmer than Sirius because it is farther away.
Vega, Deneb & Altair form the Summer Triangle. Vega is in Lyra, the only musical instrument in the sky. Orpheus played this lyre to save the Argonauts from the Sirens. The Ring Nebula is a "planetary nebula in Lyra." It would be better to call planetary nebulas "dying stars."
Cygnus flies overhead in summer. The Greeks saw Cygnus as Zeus in the form of a swan. He seduced Leda, causing her to lay an egg from which Castor and Pollux were hatched. These twins sailed with Jason and the Argonauts in their quest for the Golden Fleece. Deneb is 2600 light-years away and 60,000 times more luminous than the sun.
Leda laid a second egg, from which Helen and Clytemnestra were hatched.
Aquila and Aquarius are related. Aquarius is Ganymede the water carrier. Zeus sent his eagle to fetch him because he wanted a cup-bearer. Ganymede brings water from the river Eridanus. First magnitude Achernar is at the river's end.
Capricornus the seagoat, Delphinus the dolphin & Pisces the fish are in this watery region. The seagoat is Pan after he jumped in the river. Part of him got wet, and that part turned into a fish. Organizing stars into pictures to tell stories makes them easy to remember.
That Greek mythology survived the Scientific Revolution is a testimony to the fertile imaginations of those ancient people. The word "myth" comes from the Greek "mythos," meaning story. There are creation myths telling how the world began, explanation myths attempting to explain nature & quest myths, stories about heroes.
Magnitude measures a star's brightness. There are 21 first magnitude stars. 4 have minus magnitudes: Sirius -1.44, Canopus -0.62, Alpha Centauri -0.27 & Arcturus -0.05. Those with minus magnitudes are still referred to as first magnitude. The higher the magnitude, the dimmer the star.
21 First Magnitude Stars
..1 Sirius ---------------- Canis Major
..2 Canopus ------------ Carina
..3 Alpha Centauri --- Centaurus
..4 Arcturus ------------ Bootes
..5 Vega ----------------- Lyra
..6 Capella ------------- Auriga
..7 Rigel ---------------- Orion
..8 Procyon ------------ Canis Minor
..9 Achernar ----------- Eridanus
10 Betelgeuse -------- Orion
11 Beta Centauri ------Centaurus
12 Altair ----------------- Aquila
13 Acrux ---------------- Crux
14 Aldebaran ---------- Taurus
15 Spica ---------------- Virgo
16 Antares ------------- Scorpius
17 Pollux --------------- Gemini
18 Fomalhaut --------- Piscis Austrinus
19 Becrux -------------- Crux
20 Deneb --------------- Cygnus
21 Regulus ------------- Leo
1 Fred Schaaf claims to have seen Sirius through his window at age 6. He reveled in its hues as the light passed through our atmosphere. I was 16 when I spotted Sirius rising above the woods across the road from our house.
2 I saw Canopus from Australia. It is in Carina, part of Argo Navis, the ship on which the Argonauts sailed. Lacaille split the constellation.
3 The Alpha Centauri system contains the closest star at 4.2 light-years, 25 trillion miles. Alpha Centauri A is like our sun.
4 Arcturus exhausted its hydrogen and now burns helium. It is 37 light-years away. Arcturus hovered above my parents' back yard, where we played horseshoes and croquet.
5 Vega is a blue-white sapphire dominating the Summer Triangle. There is evidence that it has a Jupiter-like planet.
6 Like so many stars, Capella is a double.
7 Rigel was the giant Orwandil's big toe in Norse mythology. When his other big toe became frost-bitten, Thor broke it off and tossed it into the northern sky as Alcor.
8 Procyon is pronounced pro-SY-on. Star pronunciation varies.
9 Achernar is the least famous of the first magnitude stars, isolated at the river's end. In Australia, I pointed to it and asked a fellow stargazer what it was. "That's Achernar, he said!
10 Betelgeuse in Orion is the most famous star. It is a red giant. If it were in the sun's place, it would reach beyond Mars.
11 Beta Centauri is called Hadar.
12 In the movie Forbidden Planet, action takes place on the 4th planet from Altair. Altair lies between 2 dimmer stars in Aquila.
13 Acrux is Alpha Crucis in the Southern Cross.
14 Occultation is when an object hides another. Aldebaran is one of 4 first magnitude stars that can be occulted by the sun and moon. Aldebaran is the bull's-eye and fuses helium to make carbon.
15 Spica means "ear of wheat," and Virgo is drawn with wheat in her left hand.
16 Antares in Scorpius is a first magnitude star that can be occulted. It was during an occultation that its companion was discovered. Antares is flanked by 2 stars.
17 Castor and Pollux are the bright stars of Gemini. They were twins in mythology. Castor is more famous, although Pollux is first magnitude.
18 Fomalhaut is the mouth of the southern fish and thought to have a planet. I practiced the pronunciation of Fomalhaut. The h is silent: Fom-a-lawt.
19 Becrux is Beta Crucis and called Mimosa. It is near the Coalsack.
20 Deneb means tail, and Deneb is the tail of Cygnus the swan. Arabs named the stars.
21 Regulus is a flat star. Its equatorial diameter is greater than its polar diameter. Rapid rotation caused it. Leo inspired the Sphinx.
The Messier Marathon took place, April 25, 2009, at Mark Manner's Spot Observatory, 50 miles west of Nashville off I-40. Fortunately, the sky was clear. Charles Messier was the 18th century comet hunter who listed 110 fuzzy objects not to be mistaken for comets. Ironically, it is his throwaway list for which he is remembered.
It reminded me of Australia, walking out and seeing the stars after being cooped up in the city. I even befriended a married couple. He went down the list of Messier objects with machine-like precision, locating targets with his reflector. She worked at the Sudekum Planetarium and spoke of the Kepler project and its search for exoplanets.
We sampled a cross-section of objects. It was unrealistic to try to see them all. After several open clusters, they started to look alike and even in late April, it gets chilly after midnight. The M numbers we saw could have been pulled from a hat. It felt good to be under a dark sky.
M1 - The Crab Nebula in Taurus is a supernova remnant. A star exploded, leaving expanding gas and a spinning pulsar.
M35 - Open star cluster near Castor's toe containing 200 stars.
M36 - Open star cluster in Auriga, 60 stars appearing as a fuzzy object in the reflector.
M37 - Open cluster in Auriga with a red giant in the middle. Open clusters are called galactic clusters and are found along the plane of the Milky Way.
M38 - Open cluster in the middle of Auriga. Open clusters disperse after a few million years because of gravitational influences from nearby stars.
M40 - Double star in Ursa Major.
M42 & M43 - M42 is the Orion Nebula. It resembles a peacock. M43 is nearby.
M44 - The 200 stars of the Beehive cluster are sharp. Also known as Praesepe (Latin for manger), the Beehive is in Cancer. Hera sent this crab to get Hercules.
M45 - This is the Pleiades, although we did not look at it through the telescope.
M65 & M66 - 2 galaxies in Leo 35 million light-years away. M65 is edge-on. M66 is dominant.
M67 - Open cluster found by locating the Hydra's head. Colors indicate that these are mature stars: yellow, orange & red. The older a cluster is, the more red giants there are.
M81 & M82 - Galaxies in Ursa Major. M81 is a spiral. M82 is disturbed. They are only 100,000 light-years apart, and each could easily be seen from the other.
M95 & M96 - Galaxies in Leo along the lion's belly. M95 is barred.
M97 - Called the Owl Nebula, details were thought to resemble the eyes of an owl. It is a planetary nebula, a dying star giving off a shell of gas.
M105 - Elliptical galaxy in Leo.
M109 - Spiral galaxy in Ursa Major. Averted vision helped me spot this oval blur.
We saw spring constellations: Virgo and diamond-shaped Corvus. Saturn was beneath Leo. Scorpius rose, and Vega came up. The party ended with Mark showing me slides. He had a picture he took in Hawaii of the 1991 solar eclipse.
THE MILKY WAY
When I saw the Milky Way arching across the night sky as a teenager, I gave it little thought. It was a glowing band of light, nothing more. In my 30s, I realized that the Milky Way is the galaxy in which our solar system resides. We are on the edge of a spiral arm.
The Milky Way stretches from the northeast to the southwest in summer. It circles the sky, although part of it is never seen from the United States. I saw the southern piece from Australia. Light from the Milky Way is the combined glow of billions of stars thousands of light-years away. Our galaxy appears as it does because of its flat shape. It bulges at its center and tapers at its edges like a fried egg. Our solar system is located toward the outer rim. When we view the star clouds in Sagittarius, we look toward the Milky Way's center. In the opposite direction, we look toward its rim. Perpendicular to the Milky Way, we look out the top or bottom of our galaxy, where stars are scarce. The Milky Way rotates! It spins once every 240,000 years, and one rotation is known as a cosmic year. If I had known this as a teenager, I would have been a genius! It is revelation to look at the Milky Way and understand it.
Parts of the Milky Way are obscured by gas and dust. These are not holes. The Great Rift divides the stream from Cygnus to Sagittarius. In summer, we look toward the center of the galaxy in the direction of Sagittarius. In winter, we look toward the rim in the direction of Orion.
Tracing the Milky Way around the sky, I notice it in the direction of Perseus. From there, it flows to Cygnus. E. E. Barnard studied the Milky Way, and it was he who realized that the dark patches were clouds of gas and dust and not holes. The Great Rift starts at Deneb and extends almost to Crux, dividing one-third of the Milky Way into 2 streams. Barnard's starry circle flows on to Scutum, whose star cloud he referred to as the "gem of the Milky Way." It moves southward beyond Centaurus, coming close to the south celestial pole. It flows past Canopus, where it is less brilliant. I follow it past the feet of Gemini, and suddenly I am back at Perseus. Seen from afar, the Milky Way is a spiral with arms coiling around a central mass.
Astronomers have identified 5 spiral arms around the Milky Way. They are the Orion, Cygnus, Perseus, Sagittarius & Centaurus arms. We are in the Orion arm.
Stars do not revolve around the Galaxy in one piece. They move like the planets. Stars near the hub of the galaxy move fast. Those near the rim move slow.
The Hubble Space Telescope added as much to my confusion as to my understanding. Hubble images illustrate the chaos of the universe and convey a feeling of being lost in space. The Pillars of Creation in the Eagle Nebula of Serpens provides some reference. Star formation goes on in these fingerlike spires of gas.
The Hubble Ultra Deep Field was the most pervasive image before the eXtreme Deep Field. HUDF imaged 10,000 galaxies and looked back 13 billion years. It penetrated an area in Fornax one-tenth the size of a full moon. Someone compared it to looking through an 8 foot soda straw.
The eXtreme Deep Field looked back even farther. We never see objects, only light. For that reason, we are always looking back in time, whether it is a trillionth of a second when we glance at our thumb or millions of years when we observe objects in deep space.
The universe was pure energy after the Big Bang. Much of it soon froze into matter. There may be a wall of radiation keeping us from seeing the beginning. Even if we did see the Big Bang, what would it mean? We would still question. According to the New Testament, only when we are united with God through Jesus will there be true understanding.
Exoplanets have been the big thing since 1995. These are planets orbiting stars other than our own. 4000 are confirmed. They are found by indirect methods: winks and wobbles. That most are gas giants is due to the limitations of current technology. Many rocky exoplanets will be discovered.
Our immediate reaction is to think there must be other civilizations. And there may be! No one knows! Ours may be the only one, and the rest of the universe, regardless of its size, may be leftover material from God's creation of Earth.
Scientists believe that if matter is arranged in a certain way, there will be life. I am not sure. Life may be more than an arrangement of atoms and molecules. The Bible says it was created by a divine spark, the same spark that caused the Big Bang. Without God, no universe and no life!
KEPLER SPACE TELESCOPE
The Kepler mission searched for Earth-like planets. Launched in 2009, it surveyed 100,000 stars. Of the exoplanets found, most were huge balls of gas resembling Jupiter. Kepler searched for small, rocky worlds. Scientists want planets in habitable zones capable of sustaining water. It is not easy detecting planets orbiting stars at vast distances. Kepler did it by the transit method, recording changes in light as planets transited their stars.
TESS (Transiting Exoplanet Survey Satellite) supersedes Kepler as the next planet hunter.
JAMES WEBB SPACE TELESCOPE
The James Webb Space Telescope will gather data in the infrared range by penetrating gas and dust. James Webb led NASA in the years following Kennedy's moon speech.
1 Sigma Octantis
Sigma Octantis in Octans is the south pole star. It is one degree from the south celestial pole, but dim at 5.4 magnitude. It barely moves as the southern stars revolve around it.
2 Magellanic Clouds
The Large and Small Magellanic Clouds are irregular galaxies. A supernova appeared in the LMC in 1987. The light came from a star which exploded 150,000 years ago.
3 Crux (Southern Cross)
Crux is the smallest constellation.
This dark nebula is a patch of gas near the Southern Cross.
5 Alpha Centauri
A triple star, Alpha Centauri A is comparable to the sun and will be the first star humans explore.
Achernar is the 9th brightest star. Rapid rotation caused it to flatten. Achernar means "river's end," and it is at the end of Eridanus.
7 Jewel Box
The Jewel Box is an open star cluster near the Southern Cross. The jewels are blue, orange & red. These stars formed from the surrounding gas and dust.
8 Argo Navis
Nicolas Lacaille split Argo Navis into 3 constellations: Carina the keel, Puppis the stern & Vela the sail.
9 Musca and Chamaeleon
I took a fancy to Musca the fly and Chamaeleon the chameleon. The chameleon tries to eat the fly.
..1 Athlon Publications. The Great American Eclipse 2017. Nashville
..2 Bennet, Jeffrey. What Is Relativity? New York, Columbia University Press, 2014
..3 Berman, Bob. Secrets of the Night Sky. New York, William Morrow, 1995
..4 ________. Cosmic Adventure. New York, William Morrow, 1998
..5 ________. Strange Universe. New York, Henry Holt, 2003
..6 ________. Shooting for the Moon. Guildford, Connecticut, Lyons Press, 2007
..7 ________. The Sun's Heartbeat. New York, Little, Brown and Company, 2011
..8 ________. Zoom. New York, Little, Brown and Company, 2014
..9 ________. Zapped. New York, Little, Brown, 2017
10 Harrington, Philip. Astronomy for All Ages. Globe Pequot, 2000
11 ________. Eclipse! New York, John Wiley & Sons, 1997
12 ________. Star Watch. Hoboken, John Wiley & Sons, 2003
13 ________. Touring the Universe through Binoculars. New York, John Wiley & Sons, 1990
14 Kaku, Michio. The Future of Humanity. New York, 2018
15 Kaler, James. The Little Book of Stars. New York, Springer, 2001
16 Kerrod, Robin. Hubble: The Mirror on the Universe. Firefly Books, 2003
17 Littman, Mark and Fred Espenak. Totality: Eclipses of the Sun. New York, Oxford University Press, 1999
18 Olcott, William Tyler. Star Lore. New York, G. P. Putnam's Sons, 1911
19 Price, Pat. The Backyard Stargazer. 2005
20 Reynolds, Mike. Falling Stars. Mechanicsburg, PA, Stackpole Books, 2001
21 Russo, Kate. Total Addiction: The Life of an Eclipse Chaser. New York, Springer, 2012
22 Sasaki, Chris. The Constellations: Stars & Stories. New York, Sterling, 2002
23 Schaaf, Fred. 40 Nights to Knowing the Sky. New York, Henry Holt, 1998
24 ________. Planetology: Comparing Other Worlds to Our Own. New York, Franklin Watts, 1996
25 ________. The 50 Best Sights in Astronomy and How to See Them. Hoboken, John Wiley & Sons, 2007
26 ________. The Brightest Stars. Hoboken, John Wiley & Sons, 2008
27 ________. The Starry Room. New York, John Wiley & Sons,1988
28 Shostak, Seth. Sharing The Universe. Berkeley, Berkely Hill Books, 1998
29 Upgren, Arthur. Night Has A Thousand Eyes. New York, Plenum Press, 1998
30 Vamplew, Anton. Simple Stargazing. Collins, 2006
Originally written 2008-2009