The Planet Jupiter

The Planet Jupiter

The planet Jupiter is was named by the Romans after their god Jupiter, who was also sometimes called Jove. Jupiter is the largest planet in our solar system by far. It is more than twice as large as all of the other planets combined.

Jupiter might well have become a star when it was born, had it been larger. There is very little (if any) solid matter on Jupiter. If there is any at all, it is hidden deeply inside the planet. Jupiter is made up entirely (as far as we know now) of gases and liquids.

The very composition of Jupiter means that its parts do not rotate at the same speed, but rotation is fast. Jupiter makes one complete revolution in a little less than 10 hours. This very fast rotation plus the makeup of gases and liquids are what causes the bulge at the equator of Jupiter.

Jupiter has an internal heat source. We are sure of this because it actually emits more radiation than it gets from the sun.

There are four large moons and dozens of small moons that rotate around Jupiter, making it a kind of small solar system unto itself.

One of the more outstanding features about Jupiter is the never-ending hurricane called "The Giant Red Spot" in the southern hemisphere. This disturbance has been going on for the last 400 years that we know of. It never abates…probably because it never passes over land (there isn't any) like hurricanes on earth do.

An explanation for the color of the clouds on Jupiter still eludes astronomers. With the conditions that exist, clouds should be colorless, but they are anything but colorless, and they change color over time. We still have a lot to learn!

The Planet Mars

 

The Planet Mars

Earthlings have always been fascinated by the planet, Mars. The "little green men from Mars" invading Earth has been the stuff of science fiction for decades. On October 30, 1938, Orson Welles did a dramatization of H. G. Wells's "War of the Worlds" on the Mercury Theatre on the Air radio show. During the four commercial breaks of the program, there were disclaimers aired telling the audience that the content was fictional. Still, panic erupted in towns across America.

There was a new 40-inch telescope being built by the University of Chicago in 1895. An astronomy professor, Samual Leland Phelps, wrote a book about the project called "World Making." In the book, the professor wrote, "It will be possible to see cities on Mars, to detect navies in [its] harbors, and the smoke of great manufacturing cities and towns...Is Mars inhabited? There can be little doubt of it...conditions are all favorable for life, and life, too, of a high order. Is it possible to know this of a certainty? Certainly." Well…not exactly, professor!

From observations of Mars from stationary observatories on earth, astronomers concluded that:

• 1. The reddish color of Mars is caused by red rocks and dust.
• 2. The polar ice caps increase and decrease according to seasons.
• 3. There are what were thought to be canals on the surface. (That has since been disproved)
• 4. There are areas of Mars that change color. (It was believed that this was vegetation, but that has been disproved, as well.)
• 5. Mars has an atmosphere.

Space probes, beginning with Mariner 4, 6, 7, and 9 from 1965 through 1971, and the Viking 1 and 2 probes in 1976, disproved many of the previously held beliefs about Mars. We are learning more about Mars all the time, and one important fact is that there aren't any little green (or any other color) men living on Mars.

The Planet Venus

 

The Planet Venus

Back in 1686, a French scholar by the name of Bernard de Fontenelle, wrote, "I can tell from here...what the inhabitants of Venus are like; they resemble the Moors of Granada; a small black people, burned by the sun, full of wit and fire, always in love, writing verse, fond of music, arranging festivals, dances, and tournaments every day."

Nice try, Bernard, but you had it all wrong. Back in those days, it was generally accepted that Venus was much like Earth. Venus is about the size of Earth, but that's pretty much where all resemblance ends.

Almost all of the planets in our solar system travel around the sun in a counterclockwise direction…all of them except Venus and Uranus, that is. Venus (as well as Uranus) travels clockwise. All of the planets except Venus and Uranus rotate on their axis in a counterclockwise direction. Venus and Uranus rotate clockwise.

Venus also rotates really slowly, too. A "day" on Venus would equal about 243 Earth days. Venus is covered by a thick layer of clouds that make studying the surface very difficult. In the last 30 years, however, astronomers have learned how to "see" through the thick cloud cover.

In 1962, Mariner 2 was the first spacecraft to go by Venus. Since then, there have been 20 more missions. The first hard landing on Venus was done by Venera 4 in 1967. The first soft landing was done by Venera 7 in 1970.

In 1989, the Magellan spacecraft probe was launched. Magellan rotated around Venus from 1990 to 1995. It then burned up in the atmosphere of Venus. Magellan bounced radar signals off the surface of Venus and transmitted the data back to Earth.

The Planet Mercury

The Planet Mercury

The planet Mercury is the smallest planet in our solar system, and the one that is closest to the sun. This proximity to the sun has made it difficult to study the planet. The closest look that we have ever had was in 1974 and 1975 when the unmanned Mariner 10 was sent to map the surface of Mercury. Only about 40% to 45% of the surface was actually mapped.

Mercury resembles our moon in appearance as it is heavily cratered. There is an atmosphere of sorts on Mercury but not one that would sustain life as we know it. The atmosphere is very unstable and is made up of hydrogen, helium, oxygen, sodium, calcium and potassium.

Records of studies made of Mercury date back to 300 BC. The name "Mercury" was given to the planet by the Romans after the god Mercurius. Chinese, Korean, Japanese, and Vietnamese cultures refer to Mercury as the water star based on the Five Elements. Other cultures have called the planet by other names. The Babylonians, for example, called the planet Nabu or Nebu after the messenger to the Gods in their mythology.

The temperature on Mercury varies. The average temperature is 179° C, but the extremes are a low of -183 °C to a high of 427° C. Sunlight on Mercury is six and a half times stronger than it is on Earth.

There is evidence that water does exist on Mercury despite the extreme temperature variations. The bottoms of some of the deepest craters near the poles are never exposed to direct sunlight. Temperatures in these areas remain far lower than the global average, so it is possible for ice to exist.

The First Seven Astronauts

The First Seven Astronauts

Everything starts somewhere, and the space program began in earnest with the selection of the first seven astronauts that would participate in manned space flight. The NASA selection committee was made up of Charles Donlan, a senior management engineer; Warren North, a test pilot engineer; Stanley White and William Argerson, flight surgeons; Allen Gamble and Robert Voas, psychologists; and George Ruff and Edwin Levy, psychiatrists.

When the selection committee began their task, they received 508 applications. This number was reduced to 110 candidates after records were reviewed. The 110 candidates were brought together at an undisclosed location. A battery of tests were given and interviews were conducted. It took a month but the number of possible candidates was reduced to 32.

The 32 candidates were then subjected to even more stressful physical, psychological, and mental examinations. They were given full-body x-rays, tested in pressure suits, endured a variety of cognitive tests and really intense interviews. Finally, 18 or the 32 were recommended to the Mercury program without any medical reservations.

The final choices were made by Robert Gilruth, who was the head of the Space Task Group, as well as Charles Donlan, Warren North, and Stanley White.

The first seven astronauts selected for the Mercury program (the first manned space flight program) were :
 

1. Scott Carpenter, 
2. L. Gordon Cooper Jr., 
3. John H. Glenn Jr., 
4. Virgil I. "Gus" Grissom, 
5. Walter M. Schirra Jr., 
6. Alan B. Shepard Jr., 
7. Donald K. "Deke" Slayton. 

Their names will resound through history forever.

Six of the original seven flew in Project Mercury. Only "Deke" Slayton did not fly because of a heart condition that had not been discovered. Deke later flew as a crewmember of the Apollo-Soyuz Test Project.

Astronomy and The Stars

The Stars

Our sun is a star. It is one of the billions of stars in the Milky Way Galaxy. On a clear night, when you look up at the sky, you can see thousands of stars with your naked eye. If you have a pair of binoculars or a telescope, you can see more stars than you could ever hope to count.

Each star is unique, but they all share things in common as well. Stars are born from interstellar gas clouds, nuclear fusion causes them to shine and stars die. Sometimes the death of a star is a very dramatic event.

Cold interstellar clouds or nebula, like the Orion Nebula and the Eagle Nebula, are the incubators and nurseries from which stars are born. An extremely simplified description is that gravitational collapse happens and forms a rotating gas globule. The resulting globule spins faster and faster. The central core becomes a star while the other material becomes planets or asteroids.

The life of a star begins and ends with a battle between two forces: gravity and pressure. It takes energy for a star to live, and this energy comes almost entirely from nuclear fusion of lighter elements into heavier elements. This is the energy through which a star can shine for millions or billions of years.

Stars fuse hydrogen to helium for most of their lifetime. This is referred to as the "main sequence" of a star's life. Our sun, Vega, Sirius, and Spica are all stars that are in their main sequence. Once the hydrogen in the core of a star has been used up, the star becomes a red giant like Betelguese, Arcturus, Aldebaran and Antares.

A star's life is limited because the hydrogen at the core is not self-replenishing and will eventually be used up. A star cannot depend upon thermal energy to resist the pull of gravity forever, and a star's final fate depends on whether something other than thermal pressure manages to halt the relentless crush of gravity.

What Do You Know About NASA

NASA

In 1958, the Congress of the United States enacted, and the President Dwight D. Eisenhower signed, the National Aeronautics and Space Administration Act (NASA). The act begins with a very simple statement; "An Act to provide for research into the problems of flight within and outside the Earth's atmosphere, and for other purposes."
 

The Cold War between the United States and (what was) the Soviet Union was in full swing. With the passing and signing of the act that established NASA, what has come to be known as the "space race" was kicked off. The Soviet Union had launched Sputnik 1 and had an apparent head start in the race to space.

The United States caught up quickly. In January 1958, Explorer 1 (America's first earth satellite) was launched.

Then NASA launched human space flight initiatives with Mercury's single astronaut program (flights during 1961-1963) to determine if a human could survive in space.

The Project Gemini (flights during 1965-1966) with two astronauts to was used to practice space operations, like rendezvousing and docking spacecraft and extravehicular activity (EVA or space walks).

This was followed with Project Apollo (flights during 1968-1972) to explore the Moon. Since then NASA has conducted robotic missions to the Moon (Ranger, Surveyor, and Lunar Orbiter); Venus (Pioneer Venus), Mars (Mariner 4, Viking 1 and 2), and the outer planets (Pioneer 10 and 11, Voyager 1 and 2). 

NASA has had its problems over the years. The space shuttle Challenger blew up on January 28, 1986, killing seven astronauts. The space program was grounded for two years. Another tragedy happened on February 1, 2003, when the space shuttle Columbia disintegrated on re-entry. All seven people on board were killed instantly.

Space travel is not without its dangers, but space in the next great frontier for mankind to conquer. You can be sure that the space program and NASA will continue into the foreseeable future.

Careers in Astronomy

Careers in Astronomy

Sometimes when we picture an astronomer, the image of a man huddled in a cold, dark observatory peeping through a large telescope at the stars comes to mind. That might have been a fairly accurate image a half century ago, but that really is no longer the case. Today, astronomers work mostly at analyzing data that has been gathered by computers. They work in well-lit, climate-controlled rooms with a coffee maker and a plate of donuts at hand.

Careers in astronomy are many and varied, but all of them require a strong background in math and science. Those with liberal arts degrees probably won't get very far. The majority of astronomers (about 55%) are affiliated with colleges and universities in some way. Either they are professors, or they are affiliated with a college or university through an observatory or a laboratory.

Astronomers who are professors at universities and colleges are first and foremost teachers, but they usually spend some time on research. They work hard to get grants that will pay for their research. A PhD is required for all of these positions. Usually professors who are astronomers are employed through the physics department of colleges and universities.

About a third (33%) of all astronomers are employed by the federal government, and another 10% are employed by private industry. The rest are self-employed.

PhD's are not required to teach physics and earth sciences in high schools. A Bachelor or Master degree is usually sufficient.

When a young person decides to pursue a career as an astronomer, they need to concentrate their studies in the math and science field. A bachelor's degree in physics with an astrophysics option is the place to start. This should be followed by obtaining a master's degree in physics and then a doctorate in astronomy. The educational road for astronomers is long and hard, but the rewards are many.

Astronomy for Kids

Astronomy for Kids

Kids are like thirsty little sponges that soak up information. Their minds are clear, and they don't suffer from any preconceived notions like adults. Teaching astronomy to kids can be one of the most rewarding tasks that a teacher or a parent ever undertakes.

One of the most wonderful things about teaching astronomy to kids is that all kinds of other topics must be included in any astrology learning experience; science, math, history, reading, art, photography, chemistry, etc. Astronomy, while it fascinates the kid, can also act as a portal to other learning experiences.

Almost all of the great astronomers of history became fascinated by the night sky as children. Expose your children to astronomy from an early age. Encourage their natural curiosity by giving them toys that are related to astrology. There are hundreds (maybe thousands) of "space toys" available both online and off. There are posters, prints, and calendars about space as well. The Internet is packed with websites that are devoted to teaching kids about astronomy. You can find them easily by using your favorite search engine and typing the words, "astronomy for kids" into the search box.

Additionally, a wide array of astronomy software is designed for children of all age levels. There is astronomy software even for very young children like Sesame Street Ernie's Adventures in Space and Zoom Astronomy--Enchanted Learning Software. If you really want to find games, toys, software, calendars, posters, or prints that are related to astronomy for your kids, you won't have any problem at all locating it. The problem might be in choosing which to purchase.

Many little boys and girls become fascinated with space. They want to grow up to be astronomers and astronauts…and some of them will.

What About Telescopes

About Telescopes

Basically, there are three types of telescopes that are available for amateur astrologers to purchase:

• 1. Refractors that use a lens that is the primary device for gathering light. 
• 2. Reflectors that use a mirror that is the primary device for gathering light. 
• 3. Compound telescopes that use a combination of lenses and mirrors to gather light.

The type that one needs is based upon at least three factors:

1. The type of observations the user wants to make 2. The area in which the user will use the telescope 3. The financial resources of the user

First, let's talk about the location where you will be using your telescope.

• 1. If you will be using your telescope in a well-lighted urban area, you should probably go with a compound telescope, because they tend to do better than either refractors or reflectors in urban conditions.
• 2. If you will be using your telescope in the suburbs that are not as well lit as a densely populated urban area, you can choose the type telescope you want based entirely upon the type of observations you intend to make, because all types work equally well.
• 3. If you will be using your telescope in a very rural setting, you should consider compound telescopes and reflectors because they do seem to work better in very low-light situations.

The power of the telescope that you buy will depend upon what you want to observe. A small 2-4" ACH or APO refractor will work well for observing the moon and the planets, but not for observing the deep sky.

A > 6" compound will work the best for general use, but a 6"-25" reflector will work best for deep sky and faint deep sky observations.

The Solar System

Our Solar System

Our solar system consists of our sun, eight planets, the 166 known moons that orbit these eight planets, 3 dwarf planets and the four known moons that orbit them. Our solar system also includes billions of other small bodies such as asteroids, Kuiper belt objects, comets, meteoroids, and interplanetary dust.

In short, our solar system is made up of our sun and all the celestial objects that are gravitationally bound to it.

The general outline of our solar system is (from the center outward): 

• 1. The sun 
• 2. Four terrestrial inner planets (Mercury, Venus, Earth, and Mars) 
• 3. An asteroid belt (made up of rocky objects) 
• 4. Four outer planets (Jupiter, Saturn, Neptune, and Uranus) 
• 5. The Kuiper belt (made up of icy objects) 
• 6. Scattered disc (poorly understood region) 
• 7. Heliopause (where the sun's solar wind is stopped by the interstellar medium) 
• 8. And finally, a hypothetical Oort Cloud (there is a lot of ongoing debate about the Oort Cloud).

Yes, there was another planet called Pluto, but it is no longer considered a planet. Back in August 2006, the International Astronomical Union (IAU) in Prague decided that Pluto did not meet the requirements to be designated a planet, and it is now classified as one of many dwarf planets.

In the dim and dusty past, it was believed that the Earth was the center of the universe and that everything else revolved around it, including the sun. That theory changed as knowledge was gained. The telescope was invented, and men could see farther and farther.

The formation of our solar system remains a basis of contention between some religious leaders and some scientists. There are some of each who believe that God created the universe in six days, just the way creation is described in the book of Genesis in the Bible. There are others who subscribe to the "Big Bang" theory. The debate has been raging for decades and shows no signs of abating. But however our solar system came into being, it is magnificent!

History of Astronomy

History of Astronomy

Astronomy is the oldest of all sciences. It has its roots back in the beginning of time. There is evidence of astronomy playing a large role in religious, mythological, and astrological practices of pre-history. Mankind has always looked to the heavens with wonder mixed with a healthy dose of curiosity.

In the earliest cultures, heavenly bodies were identified as gods or spirits, and these gods and spirits were thought to control such things as rain, drought, seasons, and the tides. The first astronomers are believed to have been priests or Magi. The earliest calendars were based upon the phases of the moon and the time between phases.

Western astronomy has its roots in ancient Mesopotamia astrology. The modern practice of dividing a circle into 360 degrees, of 60 minutes each, began in ancient Mesopotamia with the Sumerians.

The oldest astronomical writing that we have is Tablet 63 of the Enuma Anu Enlil. It is called the Venus tablet of Ammi-saduqa. The Venus tablet lists the first and last visible risings of Venus over a period of about 21 years, and it is the earliest conclusive evidence that the phenomena of a planet were recognized.

Since the beginning of time, man has looked up. The sky, particularly the night sky, has been full of mystery that humankind wanted to understand.

The old civilizations of China, India, Greece, and Rome all looked to the stars for explanations to earthly situations and problems, inspiration and guidance. They found all of those things, but they also found knowledge, and over the centuries our knowledge of astronomy has grown. But there are those who believe that we have only just begun to learn all the heavens have to teach us.

The Galaxies

The Galaxies

First, a bit of information: A light year is the distance that light travels in one year (roughly six trillion miles). The nearest star to our sun is four light years away.
 

There are four kinds of galaxies: spiral, lenticular, elliptical, and irregular. We live in a spiral galaxy, the Milky Way Galaxy. There are dwarf galaxies that are actually satellites of the Milky Way that are a few hundred light years away. The Milky Way's nearest neighbor, however, is another spiral galaxy called the Andromeda Galaxy. The Andromeda Galaxy is 2 to 3 MILLION light years away.

Each type of galaxy has its own properties:

1. Our galaxy is a spiral galaxy. A spiral galaxy is made up of two basic components; a large flat disc shape that contains a lot of interstellar matter, and young open star clusters. Our sun is one of several hundred billion stars in the spiral Milky Way Galaxy.

2. A lenticular galaxy is a short version of the spiral galaxy in which stellar formation has ceased.

3. An elliptical galaxy is shaped more or less like a football. They have little or no angular momentum and contain little or no interstellar matter.

4. An irregular galaxy is exactly what it sounds like it would be. It is an irregular shape and it doesn't fit well within the scheme of disks and ellipsoids.

Galaxies of all shapes and sizes do have some basic common features. A galaxy contains hundreds or billions of stars like our sun. Most of the time, stars are not loners like our sun. They usually occur in pairs or binaries. Other features that galaxies have in common are:

* Globular star clusters * Planetary nebulae or supernova remnants * Clusters and associations * Super massive dark objects or black holes

Ancient Astronomical Calendars

Ancient Astronomical Calendars

Today astronomical calendars can be purchased by anybody in thousands of stores as well as on the Internet. That hasn't always been the case, however. In ancient times, the high priests or wise men guarded the sacred records of time. 

All calendars, even the modern ones that hang on our walls, are based on astronomy. In the earliest times, the passage of time was measured according to the moon. The time between full moons was the basis of the calculation of passing time, months, and seasons.

There are man-made lunar calendars that have been discovered by scientists that have date back to 32,000 years ago. There are holes in rocks, notches in reindeer bones, and tusks of mammoths that denote the days between moon phases that date back to the ice age. There are also astronomical records that are inscribed on oracle bones that date back to the Shang dynasty of the fourteenth century B.C. that show a Chinese calendar that includes intercalation of lunar months.

Because there was a need to plan for planting and harvesting crops, records needed to be kept and observatories needed to be built to precisely measure these cycles or time and seasons.

There are three basic types of astronomical calendars that have been developed and used over the centuries:

1. The lunar calendar: It was the first calendar, and it was based entirely upon the moon and moon phases.

2. The lunisolar calendar: This calendar was based upon the lunar phases, but every few years a 13th month was added to bring the calendar back into phase with the tropical year.

3. The solar calendar: This is the one that we use today. It is based upon the sun, but a correction is made once every four years to correct it. A day is added at the end of February and we call that year "leap year."

Asteroids, Comets, and Meteors

Asteroids, Comets, and Meteors

Most people lump asteroids, meteors, and comets together and consider that the terms are interchangeable. But that is a bit of a misconception. Although asteroids, comets, and meteors do share the fact that they are all bits of rock or ice that aren't part of a major planet, they really are quite different.

Asteroids:  

Asteroids are amazingly diverse. Some asteroids, like Mathilde, are more like piles of rubble that are just loosely held together. Other asteroids, like Kleopatra, are metallic in nature and are solid rock. The largest asteroid is Ceres, which is 580 miles across, and the smallest asteroids (that we know of) are only one-tenth of that size. Most of the known asteroids orbit the sun between Mars and Jupiter in the Asteroid Belt.

Comets: 

Comets are made up mostly of ice and dust. Comets have a nucleus and grow tails when they get close enough to the sun. When a comet gets close to the sun, the heat from the sun heats up the ice and vaporizes it. The gases fly off the comet and cause dust to fly up, too. A cloud of the gases and dust forms around the nucleus, and as the comet speeds through space, some of the gases are stripped of neutrons and blown back by the solar wind, forming the tail of the comet.

Meteors: 

Meteors are sometimes called "shooting stars." They are not, of course, "stars." Meteors are small pieces of interplanetary dust that burn up when they slam into the atmosphere of the earth. What's called a "meteor shower" happens when the earth passes through a field of dust that a comet has left behind. Most of the time these little pieces of rock or dust burn up completely but occasionally one will survive the impact with the earth's atmosphere and crash into the earth. These are called "meteorites."

Amateur Astronomy

Amateur Astronomy

Amateur astronomy has been around since the days of the caveman. Study and observation of the night sky has played an important role in the history of mankind throughout the centuries. Amateur astronomy is a hobby that is enjoyed by millions of people all over the world. They observe the night sky by using portable telescopes and binoculars.

Amateur astronomy differs from professional astronomy in that there is no formal funding for amateur astronomy individuals or groups. Amateur astronomers usually observe heavenly objects and phenomena. Most concentrate on observing the moon, planets, stars, comets, meteor showers, and sometimes deep sky objects like star clusters, galaxies, and nebulae.

Amateur astronomy sometimes develops into amateur astrophotography. Amateur astrophotography is the taking of photographs of the night sky. As the high-quality equipment required for pursuing astrophotography becomes more affordable, more and more amateur astronomers are investing in it and enjoying the hobby.

Amateur astronomers not only use visual astronomy techniques but also nonvisual astronomy techniques, as well, with the use of infrared filters on conventional telescopes, and also the use of radio telescopes. Some amateur astronomers use homemade radio telescopes. Others use radio telescopes that were originally built for astronomy research, but have since been made available for use by amateurs.

Amateur astronomy is a popular hobby today and is becoming more popular all the time as the price of equipment decreases. There are astronomy clubs in every part of the world.

The amateur astronomer's financial commitment to his or her hobby is usually based on two things; the degree of his or her interest and the resources available. Equipment for amateur astronomy is big business and it isn't limited just to telescopes and cameras. Astronomy software has also become big business.

Nicolaus Copernicus

Nicolaus Copernicus

Nicolaus Copernicus first became fascinated with astronomy in 1492 when he enrolled in Kraków Academy (now Jagiellonian University). His professor, Albert Brudzewski, is credited with introducing young Nicolaus to astronomy.

After four years at Kraków Academy, Nicolaus Copernicus's uncle (who paid for his education in hopes that Nicolaus would become a bishop) sent him to Bologna to study civil law. It was there that Nicolaus met Domenico Maria Novara da Ferrara, who was a famous astronomer of the time.

Copernicus gave some friends his Commentariolus (Little Commentary) in 1514. Commentariolus was a short handwritten work that described his ideas about the heliocentric (sun-centered universe) hypothesis. It was the basis for his later work.

Copernicus feared ridicule from other scientists. He wasn't afraid of what the Church would think of his theories. This fear of ridicule caused him to delay publication of his findings for several years. As a matter of fact, his book, De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) wasn't published until the year of his death in 1543.

It is said that Copernicus was in a coma that had been caused by a stroke when a friend put a copy of his book into his hands. Copernicus awakened from his coma and died peacefully shortly there after.

There are six major parts to the Copernican theory:

1. Motions of the planets are uniform. 2. The sun is the center of the universe. 3. The order of planets around the sun is Mercury, Venus, Earth and Moon, Mars, Jupiter, Saturn, and the fixed stars. 4. Retrograde motion of the planets can be explained by the Earth's motion. 5. Daily rotation, annual revolution, and annual tilting of its axis are the three motions of the earth. 6. Comparatively speaking, the distance between the earth and the sun is small to that of the earth to the stars.

Galileo Galilei

 Father of modern observational astronomy

Galileo has been called the "father of modern observational astronomy" (among other things). Galileo Galilei once said, "All truths are easy to understand once they are discovered; the point is to discover them" and he spent his life discovering truths.

One of Galileo's contributions to observational astronomy was his discovery of the four largest satellites of Jupiter, which are named the Galilean moons in his honor. He also studied sunspots and analyzed them. His studies of uniformly accelerated motion and the improvements that he made to the telescope are also considered major contributions to scientific and astronomical knowledge. The improvements to the telescope actually led to subsequent astronomical observations.

Aristotle had determined that the earth was at the center of the universe, and the sun revolved around it. Nicolaus Copernicus challenged that theory in the 1530s. Galileo was one of the very few thinkers of the time who adopted the Copernican theory before 1600.

Galileo published an account of his telescopic observations of the moons of Jupiter in 1610. The following year, he visited Rome to demonstrate his findings to philosophers and mathematicians of the Jesuit Collegio Romano to let them see that the four moons of Jupiter were real. Indisputable visual proof, however, was not enough.

The Catholic Church prohibited the advocacy of heliocentrism (a sun-centered universe). Galileo managed to evade the Roman Inquisition for a full year, but he was finally forced to recant his belief in heliocentrism, and he spent the last years of his life under house arrest.

Orion AstroView 90mm Equatorial Refractor Telescope

The Orion AstroView 90mm EQ Refractor is a planetary power-performer with its 90mm aperture and 910mm focal length. Views of the planets and Moon through the f/10 AstroView 90 telescope are nothing short of spectacular. When aimed at our nearest neighbor in space, the Moon, the AstroView 90 yields tack-sharp views of the rocky lunar surface with craters and mountainous regions visible in crisp, high-contrast detail. You'll find yourself transfixed by the rugged relief of the Moon's surface as shadows along the terminator enchant your eyes. On a reasonably clear evening, Jupiter's cloud banding becomes starkly visible in the AstroView 90mm EQ, as do all four of its major Galilean moons. Depending on the time of year, the Orion AstroView 90mm EQ Refractor can also provide the whole family with jaw-dropping views of Saturn and its stunning rings, not to mention glimpses of big Saturnian moon Titan.

With 90mm of aperture, the AstroView 90mm Equatorial Refractor Telescope can also provide great views of many deep-sky phenomena. With the 25mm Plossl eyepiece installed in the telescope to provide 36x power magnification, our namesake deep-sky object, the Orion Nebula, exhibits the four Trapezium stars as perfect blue pinpoints surrounded by a pretty patch of greenish gas. If you pop in the included 10mm eyepiece to bump up the power to 91x magnification - Wow! - the nebula will appear sprout cloudy wings, which span nearly the entire eyepiece field of view!

The AstroView 90mm refractor is supported by the substantial Orion EQ-2 equatorial mount, which allows for easy manual tracking of celestial objects as they appear to migrate across the night sky. An occasional tweak of the equatorial mount's R.A. (Right Ascension) slow-motion cable will keep any object centered in the telescope eyepiece. You can also use an optional electronic motor drive for more automated, hands-free tracking of any centered object (drives sold separately). An adjustable tripod lets you set the telescope to a comfortable height for a long night of solo stargazing, or you can change the height throughout the evening for a night of family fun with the stars.  There's even a handy accessory tray that fits onto the tripod for convenient storage of gear while you're out in the field.

The Orion AstroView 90mm Equatorial Refractor Telescope will provide you and your family with many evenings of heavenly browsing at an unbelievably low price. The telescope comes fully equipped with a 6x30 achromatic finder scope, two fully coated 1.25" Sirius Plössl telescope eyepieces (25mm and 10mm), a 90° mirror star diagonal, dust cap, and 1/4"-20 adapter on one of the tube rings for piggyback camera attachment. The assembled telescope weighs just 23.7 lbs. total, so it's easy to take outside for impromptu observing sessions.

Sir Christopher Wren

Sir Christopher Wren once said, "In things to be seen at once, much variety makes confusion, another vice of beauty. In things that are not seen at once, and have no respect one to another, great variety is commendable, provided this variety transgress not the rules of optics and geometry." For those of you who do not know, Christopher Wren was an English architect and mathematician who became Savilian Professor of Astronomy at Oxford in 1661. He is most famous for the buildings that he designed after the Great Fire of London.

Wren was interested in many things, and over his lifetime, he made many contributions to scientific knowledge and in many different ways. For example, he constructed a transparent beehive for the purpose of scientific observation; he studied the moon and experimented on terrestrial magnetism; and he also performed the first successful injection of a substance into a dog's bloodstream.

Along with Sir Paul Neile, Wren constructed a 35-foot telescope. During this timeframe, Wren also studied and improved the microscope and the telescope.

Wren was fascinated by the planet, Saturn. He began his observations of Saturn about 1652 with the intention of explaining the rings. Wren developed a hypothesis which he wrote in De Corpore Saturni. Before his work could be published however, Christian Huygens (a Dutch astronomer) presented his theory of the rings of Saturn. Wren immediately recognized the fact that Huygens' was a better hypothesis than his own, so De Corpore Saturni was never published.

Wren constructed a beautifully detailed model of the moon and gave it to the king. Although Sir Christopher Wren eventually turned his attention to architecture, he remained fascinated by astronomy all of his life.

The Most Famous Meteorites

  Most Famous Meteorites

 

 Meteorites might all be considered somewhat "famous" in that they are extraterrestrial bodies that have fallen to earth. Most of the time, meteors burn up once they come into contact with the earth's atmosphere; but sometimes these meteors reach earth still somewhat intact, and then we call them meteorites. Some meteorites are more famous than others simply because of their size, their composition, or the force with which they strike the earth.

Some of the most famous meteorites are:

The Hoba meteorite:

The Hoba meteorite is the largest meteorite that has ever been found on earth. The interesting thing about the Hoba is that it didn't create a crater. It is believed that it entered the earth's atmosphere at such a shallow angle that it was slowed down by atmospheric drag. The Hoba meteorite is located at Hoba Farm, near Grootfontein in Namibia in the same place where it was discovered in 1920. It is an iron meteorite that weighs more than 60 tons.

The Anighito meteorite:

The Ahnighito meteorite is the second-largest meteorite ever discovered and it weighs a mere 34 tons. It was found by Admiral Peary in 1892 at Cape York in Greenland.

The Willamette meteorite:

The Willamette meteorite is the largest meteorite ever discovered in the United States. It was found in Oregon and it is now at The American Museum of Natural History in New York.

The Sikhote-Alin meteorite:

The Sikhote-Alin meteorite made a dramatic entry on February 27, 1947, in the Sikhote-Alin Mountains in Primorsky and Khabarovsk Krais, Russia. A great many astrologers (both professional and amateur) spotted the huge fireball headed for earth. When the Sikhote-Alin meteorite hit the earth's atmosphere, it began to break apart but a the total mass of the Sikhote-Alin meteorite is estimated at between 70 and 90 tons.