Background
The Universe
As an amateur astronomer, very amateur one at best, I have learned that astronomers estimate that the Universe is made up of hundreds of billions of galaxies, each with up to a few 100 billion stars. That is a total of well over 10,000 million million million stars. (Couper, 1992) This number, if written out would stretch almost across a page. It is very difficult to imagine a million stars and 100 billion times 100 billion is incomprehensible. Since we can't see the entire Universe some scientists estimate that there may be 20 trillion galaxies in the Universe. That would be 20 trillion galaxies with how many stars each? Now we are really getting to some serious numbers.
Galaxies, giant groups of millions or even trillions of stars, are not spread out randomly, but organized into clusters of galaxies with as many as tens of thousands of galaxies in each cluster. Now we are really getting into some numbers that are really incomprehensible. But there is more, they do not fill the entire Universe. There are vast amounts of space between them. Some of these huge voids are 150 to 200 million light-years across. Although there may be billions, perhaps even trillions, of galaxies, the void is greater than the space occupied by matter in the Universe. To put it bluntly, space is full of holes.
The Milky Way Galaxy
We will begin by studying a small part of the Universe. Within the Universe and in its vastness is the Milky Way Galaxy, our galaxy. Imagine living in a city with 200 billion inhabitants, so vast that it would take a jumbo jet 100 billion years to cross it. (Couper, 1992) We live within that "city" and we call it the Milky Way Galaxy. The Milky Way Galaxy, a huge spiral-shaped glowing collection of some 200 billion stars, is approximately 150,000 light-years across and one thousand light-years thick. At the sped of light it would take 28,000 years to get from the local neighborhood to the center of the galaxy. (Levy, 2002) The center bulges out and is about 20,000 light-years across and three thousand light-years thick. The center consists of very old stars, but little dust or gas. There may even be a huge black hole, filled with black matter, in the very middle of the Milky Way. The entire Galaxy whirls rapidly, spinning our Sun and all its other stars around at 100 million km/h (62 million miles per hour). (Farndon, 2001) Astronomers now know that there are in excess of 100s of billions stars in the Milky Way Galaxy alone (Freedman 2002) and our Sun, a local star, is just a minor member of this star city. On a dark night, if you are outside in an area that is very dark, you can trace the path of the Milky Way because the galaxy is flattened and the stars are concentrated into a hazy band. Just look up for an area that has so many stars that looks like the stars have gathered together and you will see what I mean about the hazy band. The stars appear to be so concentrated that the Milky Way is visible as one wide band across the sky. I have spent many nights looking up at the Milky Way trying to imagine what our universe looks like from other planets and wondering if there are some living beings looking up into their night sky wondering if there are other planets with someone looking back at them.
Our Galaxy is just one in a group of about 30 galaxies that cluster together around the Milky Way and Andromeda Galaxy. These galaxies range from 170,000 light-years to 4 million light-years from the Milky Way. The majority of these galaxies are relatively small, containing only a few million stars each. These small dwarf elliptical galaxies are thought to be them most common galaxies in the Universe. The Larger Magellanic Cloud Galaxy is 170,000 light-years away. Andromeda Galaxy is thought to contain about 400 billion stars and one of the biggest spirals known. It is the largest object visible without the aid of a telescope and although it is not exactly next door in the vastness of space it is not considered to be that far away either. Andromeda, the second closest galaxy, is only 2,200,000 light-years away. That makes it 21 quintillion km or 9 quintillion miles away. Written out it becomes 21,000,000,000,000,000,000, a number so large that it becomes meaningless. One light year is about 10 trillion km. Astronomers use Parsecs when discussing distance. One Parsec is equal to about 3.3 light years or 206,000 AU, as a unit of distance. No matter how you measure it, in light-years, Parsecs, kilometers, or miles, it is still too far for me to comprehend the distance.
The Solar System
As we explore the Universe and get closer to home we locate our Solar System. Located within the Milky Way Galaxy, it consists of one local star, our Sun, 9 known planets, about 70 moons, millions of comets, and countless asteroids. Scientists believe that the most distant edges of our Solar System may be 17.6 billion km (11 billion miles) from the Sun. (Hirschmann, 2002) If you could observe the solar system from a point several astronomical units (AU) above the Earth's North Pole, you would see that all the planets obit the Sun in the same counterclockwise direction. (Freedman 2002) Pluto is an exception. Its plane of orbit is tilted at about 17 degrees to the ecliptic. The four inner planets, Mercury, Venus, Earth, and Mars, are called terrestrial planets because resemble the Earth. Like Earth they all have hard, rocky surfaces with mountains, craters, valleys, and volcanoes. You could stand on the surface; but you would need to wear protective spacesuits if you were on Mercury, Venus or Mars. The outer planets are called Jovian planets because they resemble Jupiter. The composition of these planets is mostly gaseous or liquid and landing a spacecraft on the surface the Jovian planets would be futile. The visual surfaces are actually cloud formations in the planet's atmosphere. During our classroom exploration of our Solar System we will be examining each planet.
The Sun
Our Sun is located two-thirds of the way out in the galactic suburbs. It is not only the center of our Solar System, it also provides the light and heat energy for our Solar System. The enormous gravitational pull of the Sun keeps the planets in elliptical, or oval, orbits. It is 1.4 million km in diameter, one hundred times the diameter of the Earth, and has a mass 330,000 times heavier than the Earth. Just try to imagine the size of a dry green pea as compared to a dark green Black Diamond watermelon and you just might be able to understand the difference between the Sun and the Earth.
The Sun is located approximately 149.6 million km from Earth and 9.45 million million km from the nearest star. Every second, the Sun converts 4 million tons of itself into energy. One would think that the Sun has a limitless source of power in the nuclear fusion of Hydrogen that take place at the core. For us, it has a limitless source of power as it should last about another 5 billion years. At the time it begins to run out of fuel, it will have swollen until it is twice as bright and fifty percent larger than the current Sun. This stage will take about another five billion years. When it runs out of fuel its core will start to shrink. As the core shrinks, the rest of the Sun will swell up and our Sun will become a red giant star. At this point it will have engulfed Mercury, Venus, Earth, and Mars. It will eventually evolve into a white dwarf star about the size of Earth and with perhaps one/tenth of its luminosity. (Freedman, 2002) With the passage of eons our Sun will be just another dark cinder in the vast expanse of space. We don't have to panic, and we are not at the brink of extinction, this process will take billions of years. Who know where mankind will be capable of traveling by then.
Presently our Sun, like most stars, is an immense globe of glowing hydrogen gas. The hydrogen at the center or heart of the globe is so hot and compressed that hydrogen atoms fuse to make helium. (Couper, 1992) The core temperature is an estimated 15 million degrees Celsius (27 million degrees F.). As the nuclear reactions take place the energy floods outward by radiation up to about 70% of the solar radius. Once this energy reaches the outermost 30% of the radius (the so-called convection zone) it continues its upward motion and is carried by the Sun's gases, which rise and fall in huge bubbles. The energy emerges at the surface, the photosphere, as heat and light and is a mere 5,700 degrees Celsius (over 10,000 degrees F.). Even if it seems to be cooler it is hot enough to vaporize every substance known to man. Above the photosphere is the Sun's atmosphere which is divided into the chromosphere and the corona. The corona feeds fast-moving gas into the "solar winds" that rush away from the Sun at speeds of up to 3 million km/hr. These charged particles (mostly protons and electrons) generate magnetic fields and electric currents and all the planets orbit inside this magnetic environment, the heliosphere. The heliosphere acts as a protective bubble, cocooning the Sun's family of planets from the cosmic radiation that exists between the stars. (Couper, 1992) What makes our Sun so spectacular is that it has a luminosity of 390 billion billion megawatts. Each inch burns with the brightness of 650,000 candles.(Farndon, 2001) The Sun's influence extends to the very edge of the Solar System.
Space observatories like SOHO (Solar and Heliospheric Observatory) are enabling astronomers to learn a great deal about the Sun. The SOHO satellite circles the sun sending back information not available through the use of Earth bound telescopes. The scientific data being sent to NASA is priceless.
It is amazing that up until about 500 years ago people generally believed the Earth was the center of the Universe. Nicolaus Copernicus, a Polish astronomer, noticed that the planets did not always seem to travel in the same direction. He claimed that the Sun was at the center and all the planets traveled around it. It is called the heliocentric view. He described his ideas in a book called De revolutionibus orbium coelestrium ("On the revolutions of the heavenly spheres"). The Roman Catholic Church banned his book for almost 300 years, but it did not stop others from debating the authenticity of his ideas. In 1609, an Italian astronomer, Galileo Galilei used a telescope to study the sky. Galileo discovered moons near Jupiter and saw that they were revolving around the huge planet. He had proof that Copernicus was correct but it took a couple more centuries before people generally agreed with Copernicus and Galileo. On the other hand, we now know that even the Sun is not at the center of the Universe, but it is, instead, one of hundreds of billion stars in one of hundreds of billion galaxies in the Universe. Makes one feel rather small and insignificant just thinking about the vastness of space and how little we actually know about it.
Mercury
After studying the Sun and its role in our Solar System we will then begin studying the planets as they line up from the Sun to the outer limits. Mercury, with an orbit between 45.9 and 69.7 million km (28.5 and 433 million mi), is the closest to the Sun. With daytime temperatures over 430 degrees C (806 degrees F), hot enough to melt lead, and night temperatures dropping to a -180 degrees C (-292 degrees F) I don't imagine anything being able to survive. Cap it off with a thin atmosphere of sodium vapor and the extreme temperatures are definite clues that life as we know it cannot exist on Mercury.
Venus
The second planet from the Sun is Venus. Its orbit around the Sun is from 107.4 million km (66 million mi) at its nearest and 109 million km (67.7 million mi) at it farthest. Venus is the hottest planet in our Solar System with temperatures reaching over 470 degrees C (878 degrees F). This is hot enough to melt lead. This extreme temperature was caused by the greenhouse effect. Venus began slightly hotter than Earth and the rocks on Venus could not absorb the carbon dioxide gas that was released into its atmosphere by its volcanoes. Today Venus is covered with thick clouds of carbon dioxide gas and sulfuric acid. It is remarkable that Earth, which is almost the same size as Venus, has a breathable atmosphere. Rocks on Earth absorbed the excess carbon dioxide gas. Had Earth been as hot in the beginning as Venus it is most likely that Earth and Venus would have the same type of atmosphere.
Not much is know of Venus' surface since it is covered with dense clouds. In the 1980's the Magellan orbiter sent back a photo, created on computer from radar data, of the Maat Mons volcano showing that is 6 km (3.7 mi) high. Without the use of the radar data the surface of Venus would be a total mystery.
Earth
The "third rock from the Sun" is the Earth. On January 3 rd we are 86 million mi from the Sun. This is called the perihelion. On July 4 th we are at its farthest position from the Sun, the aphelion. Earth is 146.8 million km, (91.2 million mi) away from the Sun during the aphelion. Earth, the fifth largest planet, is the only planet in our Solar System that has liquid water, which covers over 70 % of it's surface, and has an atmosphere that its over 700 km (435 mi) deep, mainly of harmless Nitrogen and life-giving Oxygen. The Earth is just the right distance from the Sun for the temperatures to stay an average 15 degrees C (59 degrees F). However, without the greenhouse effect caused by the Earths atmosphere, the temperature would be below the freezing point of water, and the Earth would be frozen over. We will be using the attributes of Earth to establish the possibility of "life as we know it" on other planets.
Earth is the only planet of the inner planets to have a moon. When I was about six my granddad told me our Moon was made of green cheese and that there was a man in the Moon. He loved to tease us. I didn't really believe him but after all he was my granddad and I couldn't say I didn't. Since then astronauts have landed on the Moon, walked on the Moon, and brought back samples of the lunar surface. I remember watching the first lunar landing, July 20,1969. I don't think I said a word the entire time. Watching Neil Armstrong climb out of Apollo 11 and stand on the Moon was the most exciting event I had ever seen. I was completely mesmerized by the accomplishments of our space program.
"Houston, the Eagle has landed." Those were the first words spoken from the surface of the Moon. When Neil Armstrong stepped on the Moon I was listening as he uttered his now famous words: "That's one small step for a man; one giant leap for mankind." I still get chills just thinking of that history making mission. Between 1969 and 1972 twelve men landed on the Moon. They brought back 380kg (838 lb) of Moon rock. There is one on display at Space Center Houston that everyone is allowed to touch. It is not the same as going there, but after all it is a Moon rock all the same. They left a mirror to reflect a laser beam which measured the Moon's distance from the Earth, a United States flag, the Lunar Rover, and their footprints.
Mars
There has been a lot of news about Mars lately with the Mars Rover sending back the pictures of the surface. Students may have the misconception that Mars would be a good place to establish a U.S. colony. The facts provided may help them decide if they would like to journey to Mars or not. One thing they will have to learn is if Mars has an atmosphere that can sustain "life as we know it". Mars, the fourth planet from the Sun, is called the red planet because of the rusty red color that comes from oxidized iron in its soil. It orbits at an average distance of 227.9 million km (141.6 million mi) from the Sun, and takes 687 days to complete its orbit. Mar's surface is cracked by a valley called the Vallis Marineris, so big that it makes the Grand Canyon look tiny. (Farndon, 2001) There is evidence of past volcanoes, a Polar ice cap, craters, but no liquid water. In fact, liquid water could not exist on Mars today, since for its present atmosphere, the boiling and melting point of water are equal to each other, so that upon melting, any water or ice would become vapor.
Mars has been the subject of numerous missions. In the 1970's the U.S. Vikings, 1 and 2 and the Soviet Mars 3 and 5 probes reached mars. Mars 3 send back data for 20 seconds and the fell silent. The aim of the Viking missions was to find signs of life, they found none. They send back plenty of information about the geology and the atmosphere. Then in 1997, on July 4 th, the U.S. Mars Pathfinder probe arrived on Mars. Live TV pictures were beamed back. Sojourner, a wheeled robot vehicle, sent back pictures of a rocky area. Together the Pathfinder and Sojourner took more than 16,000 pictures and operated for 83 days. This would be a great time to visit NASA's web site for all the statistics you will ever need on all its missions. Can Mars sustain "life as we know it"? This question is rhetorical and has been answered by NASA after every probe and mission.
Asteroid Belt
Once you venture past Mars you come to the Asteroid Belt. This area of space is littered by lumps of rock that orbit the Sun. They range in size from miniscule to over 100 km (60mi) across and it is estimated that there are more then a half a million in orbit between Mars and Jupiter. If you fit them altogether they would not make a world as large as our moon. (Simon, 1992) The first and largest asteroid, measuring 940km (540mi), was discovered in 1801 by Giuseppi Piazzi. He was actually looking for a missing planet when he found Ceres. Since then astronomers have been discovering more and more of these mini-planets. In 1991 and 1993 the Galileo space probe took close-up pictures of the asteroids Ida and Gaspra.
Jupiter
Jupiter, 778.3 million km from the Sun, is the largest planet in our Solar System. With an atmosphere of gaseous Hydrogen and Helium there is no surface for a spacecraft to land. It takes less than ten hours for the giant to spin around whereas it takes the Earth almost 24 hours. That means it is moving at nearly 50,000km/h (31,000mph) and that is really fast for such a large planet. One feature about Jupiter is that it has a Great Red Spot which is a huge swirl or red clouds measuring 40,000 km (25,000mi) across. This was first noticed by Robert Hooke in 1644. Galileo was the first to spot Jupiter's four moons, Io, Europa, Callisto, and Ganymede. Each of these four moons has distinct color and patterns. Ganymede is the largest and it looks like it would be very solid but under the outer shell of ice is 900 km of slushy, half melted ice and water. Callisto is scarred with craters. One of the craters, Valhalla, is so big that it looks like a giant eyeball. Io's surface is a mass of volcanoes, possibly the only moon with active hot volcanoes. Europa's surface is covered with ice and resembles a billiard ball with countless cracks. There are 24 smaller named moons and 12 more have discovered recently. They may have names now, we will just have to check with NASA to see.
Saturn
Saturn, the second largest planet, is my favorite planet. I think it is because of the rings and the mystery surrounding them. These rings consist of thousands of narrow, closely spaced ringlets. It had long been speculated by astronomers that they are made of ice and ice coated rock. The hunch was confirmed in the 1970's, when the American astronomers, Girard P. Kuiper and Carl Pilcher identified absorption features of frozen water in the rings' near-infrared spectrum. (Freedman, 2002) Voyager 1 and Voyager 2 flew past Saturn in 1980 and 1981. Using even more detailed infrared measurements they indicate that the temperature of the rings ranges from -180 degrees C in the sunshine to less than -200 degrees C in Saturn's shadow. Yes indeed, it is cold on those rings.
Saturn is made almost entirely of gas, mostly Hydrogen and Helium, but it has a very powerful magnetic field and sends out strong radio signals. It takes just 11.5 hours to rotate once, making it the second fastest, just behind Jupiter. It turns around at over 10,000km/h (6,125mph). It is also a very windy planet with winds ten times stronger than any hurricane on Earth, and the winds never let up. Remember I said the mystery of the rings made it my favorite, not that I would like to live on or even visit Saturn.
Since NASA has been sending probes more has been learned about those mysterious rings. One thing that is not a mystery is the fact that Saturn has at least 30 moons. One of NASA's missions sent back information about some of these moons. The largest is Titan at 5,140 km (3,190 mi) and it is the only known satellite in our Solar System with an appreciable atmosphere. The most current facts about our Solar System are being updated almost daily thanks to NASA and Earth bound astronomers alike.
Uranus
When I was growing up we were taught that only Saturn had rings. Thanks to the space program we now know that Uranus has a very faint set of rings that are made of the darkest material in the Solar System. (Farndon, 2001) Uranus, located 1.8 billion km (1.1 billion mi) from the Sun, tilts so far on its side that it seems to rotate in the opposite direction of all other planets. The angle of its tilt is 98 degrees which puts it equator running from top to bottom. This radical tilt means its north and south poles point toward and away from the Sun during its summer and winter. These seasons on Uranus are approximately 21 Earth years. Spring and fall, by contrast, are extremely short. Speculation has it that another planet or perhaps a meteor collided with Uranus, thus causing the excessive tilt. As a result of the angle of its tilt the Sun sets backward during Uranus spring.
Thanks to Voyager 2 and other NASA missions we have been able to learn more about our outer planets. Uranus has 21 confirmed satellites ranging in diameter from twenty-six km to 1520 km. One of these satellites, Miranda, has a landscape unlike that of any other world in our Solar System. Of course it is heavily cratered, as one would expect, but there are regions that look as those something has taken a rather large "bite". These areas have enormous cliffs that jut upward to an elevation of 20 km, twice as high as Mount Everest. (Freedman, 2002)
Uranus, with an icy atmosphere made of Hydrogen and Helium, is very, very cold mainly because of its distance from the Sun. It would not be a good place to live as the surface is an ice-cold ocean of liquid methane gas thousands of miles deep. A space ship could not land on Uranus. The liquid methane gives it a beautiful color but even a fraction of a second in that ocean and you would freeze so hard you would shatter like glass. Even with those beautiful rings I would never get to enjoy them in this atmosphere.
Neptune
If you keep going away from the Sun until you reach between 4.6-4.54 billion km (2.77-2.82 billion mi) you will reach Neptune. Neptune's surface is composed of icy cold liquid methane and it has an atmosphere of Hydrogen and Helium. Neptune has a thin layer of rings too. It has a Great Dark Spot on its beautiful blue surface. Like Jupiter's, it is where storms whip and swirl the clouds. There are eight moons, all named after characters from Ancient Greek myths, around Neptune. Triton, the largest, actually orbits Neptune oppositely to the direction in which the planet rotates. It looks like a green melon with pink icing at each pole. Triton's surface does not have large craters. This is an indicator that it either has a young surface, or ancient impacts have been erased by tectonic activity.
Voyager 2 observed plumes of dark material being ejected from the surface to a height of 8 km. These plumes are similar to geysers on the Earth. (Freedman, 2002) However, when they erupt they spew out fountains of ice. When you are that far from the Sun you shouldn't expect hot molten lava.
Pluto
Pluto was the last planet to be discovered. Perhaps that is because it is not only the farthest from the Sun it is also the smallest. Earth's diameter is five times bigger than the diameter of Pluto, and 500 times as heavy, like comparing the size of a basketball to a ping pong ball. Pluto is made from rock, but it is covered in water ice, and a thin layer of frozen methane. Only imaginary pictures of Pluto exist. Not even the Hubble space telescope could get an image to show any details. American astronomer James Christy was studying a photo of Pluto and noticed a bump. Now most of us would just think it was a flaw in the print, but it turned out to be a large moon, about half the size of Pluto. They orbit one another with the moon, Charon, always in the same place in Pluto's sky.
More to the Universe than Planets
There is more to the Universe than just planets and asteroids. There are so many stars that one cannot count them. One of my students could not think of a mathematical term for more than a trillion so he just said Kazillion. To him it simply meant a number too large to count, or write, or even comprehend. Of course he was talking about how old I was and at the time I believe he was kidding.
Long ago, before telescopes and before any known navigational tools, people navigated by using locations of stars and star patterns. They learned that certain stars were in a specific area of the sky at any given time during the year. In the northern hemisphere one star in the Big Dipper, Ursa Major, was used to locate north. Once north was located it was just a matter of deduction to locate south, east and west. People actually traveled long distances with the stars to lead the way. Early sailors relied totally on the Sun and stars for navigation. The Sun was used to navigate during the day. Today although most people don't think of using the Sun or stars as navigation tools the process is still the same. The Sun still rises in the east and sets in the west and the north star, second from the end of the handle of the Big Dipper, is still in the northern sky at night in the northern hemisphere.
A fellow teacher went to New Zealand to teach for a year and completely forgot that the stars they see are not the same ones we see here in the northern hemisphere. Their constant in the southern hemisphere is the Southern Cross, Crux. It is used to locate south and is used by the indigenous people of the southern hemisphere for navigation. Due to the curvature of the Earth there is a different set of stars for the northern and southern hemispheres. Only if you are on, or close to, the equator would you see the stars of both hemispheres. That would be a wonderful field trip for any age student, star gazing from the equator. Of course they would need a chaperone. And that is what I would call the perks of the trade.
We have two stories in our reading basal that tells about people that used the stars for navigation. Harriet Tubman and the Underground Railroad relates the story of how run- away slaves were taught to follow the North Star to freedom. They called the Big Dipper the Drinking Gourd. They slept hidden during the day and followed the North Star by night. Once the Big Dipper is located it is easy to find the North Star, just find the handle and Alcor and Mizar, the North Star is the second one from the end of the handle. The other story is about the Cliff Dwellers in Colorado. This story tells of how they traveled from pueblo to pueblo using the Sun and stars as navigation tools. At Chaco Canyon in New Mexico scientist have been studying how the Anasizi were able to place windows in their Kivas so that on the summer solstice the Suns rays would shine through that one window into the Kiva. This is the only day the Sun enters the building directly and it enters at precisely the center of the building. Another amazing fact in these cities is that all the major buildings had walls that faced true north, south, east, and west. Just as astonishing are the roads that lead from pueblo to pueblo. They did not meander, they headed directly from one to other. These ancient people had to have studied the stars and the Sun to be able to use them as navigational as well as building aids.
We also study about the Lewis and Clark expeditions. At the time they began their journey they had compasses to use. However, if necessary they could travel without a compass. People learn how to navigate by using the Sun and the stars. By day they could follow the Sun as it rose in the east and set in the west. By night they used the North Star in the Big Dipper. Although the angle of the Sun changed during the winter months the direction it rose and set did not. I don't remember them getting lost and if they did it was not due to not knowing the direction they were to go.
Explanations for the Seasons
Have you ever tried to explain why we have seasons? Try asking your students and see what they say before you go into the details. Of course we know it is because the northern hemisphere of the Earth tilts away from the Sun in the winter time and toward the Sun in the summer. As the Earth tilts away from the Sun the northern hemisphere gets less direct Sun rays. The northern hemisphere has fewer hours of light during a 24 hour time period and it gets colder, gradually of course, in the winter. It is just the opposite during the summer. The Sun skims the horizon most of the day; setting only momentarily during the middle of what is the night in the lower half of the northern hemisphere. In March and again in September the northern and southern hemispheres receive equal amounts of sunlight. As the northern hemisphere has summer the southern hemisphere has winter and vice versa. I can't imagine it being cold in July and August and my cousin in Melbourne can't imagine not having a possibility of snow during those months.
Extraterrestrials (ET)
Is there really life other than on Earth? Man has been trying to find the answer to that for generations. Some scientists say that ET life could develop elsewhere in the Universe. Other scientists believe that if there is ET life anywhere in the Universe it must be based on the chemistry of Carbon and that it would be as life on Earth. It is also believed if there is life on any other planet in our Solar System it would be very primitive. Is there life elsewhere in the Universe?, in another solar system?, that is another guess altogether. My students will use what they learn about our Solar System and their imaginations when writing their fictional story about space travel. Once they have all the facts I can give them they can use those facts to make their story as real as possible.
Is there really life on other planets? The problem is that the time it would take to travel to and from another solar system would require a much more technologically advanced society than we have. Is it possible to invent a method of transporting living beings across the Solar System and back? No one on Earth has been able to do it yet. We don't have the advanced technology at this time and so far there has been no real proof of any other world that has that capability either. We will just have to let our imagination do the dreaming for us.
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