Approximately 4.6 billion years ago our solar system was formed, which is comprised of 8 planets, 146 moons, 3 dwarf planets, and millions of stars, asteroids and comets. All of these celestial bodies rotate around the sun, each having their own orbital path. Using a small telescope or binoculars, all eight planets can be seen. Some can be spotted with the naked eye. The solar system has always caused wonder in humans, and with the help of NASA and continuously advancing technologies, people are able to learn more than ever about this vast system.
The Sun is a glowing sphere of hot gas made up mostly of hydrogen and helium, with small amounts of carbon, nitrogen and oxygen, neon, iron, silicon, magnesium and sulfur. Because the Sun is burning the hydrogen into helium, it shines, and as time passes the sun has less hydrogen and more helium. It is located 93 million miles from earth, with a gravity field that is 28 times greater than Earth’s gravity. The length of one day is 609.12 hours, or the equivalent to 25.38 Earth days. The Sun’s temperature averages at about 10,000 °F. It is estimated that the Sun is 4.6 billion years old and approximately 92.1% of the Sun’s composition is Hydrogen and about 7.8% is Helium. The Hinode mission is currently studying the Sun by using a satellite equipped with a Solar Optical Telescope, an X-ray telescope, and Extreme Ultraviolet Imaging Spectrometer. This is an international mission with collaboration between Japan, the United States, the United Kingdom and Europe.
- Sunlight, Sun Bright provides detailed information and images of the Earth’s sun
- Sun Facts learn about the Earth’s sun and how it affects our environment
- Berkley has a great webpage with solar facts and images.
The Moon moderates the Earth’s wobble, making it an inhabitable and relatively stable climate. It is suggested that after a Mars-sized body collided with Earth the resulting debris formed the moon. The average distance to the Moon is 238,885 miles. The Moon has about 0.116 of Earth’s gravity. The length of a Moon day is the equivalent to an Earth day. The extremely cold temperatures of the craters on the dark side of the Moon are colder than the temperatures of Pluto. Three Indian satellites and two NASA probes have picked up the light signature of water (H2O), or hydroxyl (OH), or both while mapping the moon. These molecules re bound to other molecules and are only found in trace amounts.
- Washington University’s Lunar Meteorites page is an interesting read with lots of pictures and information pertaining to meteorites from the Moon.
- Moon Phases with photos to better understand the moon’s affect on the Earth and how important it is to the environment.
- Basic Moon facts learn how the Moon impacts our world.
As the smallest and densest planet in the Solar System, Mercury is the closest planet to the Sun at about 36 million miles distance. It does not have much of an atmosphere. About 3/4th of its radius is made up of a large metallic core and has a rocky mantle and crust. Mercury has ice at both poles. One day on Mercury is equal to 176 Earth days. Average daily temperature is 840 °F. If a person weighs 100 pounds on Earth, they would only weigh 38 pounds on Mercury. Water ice may exist in the bottoms of craters at Mercury’s poles, according to recent data.
- The Messenger website will provide scientists with a lot more knowledge about the plant. This page has lots of great pictures and video about Mercury and the Messenger mission.
- PDRS Discoveries discusses the little planet Mercury, including its surface, statistical information, and pictures.
- Slashdot website provides pictures and information from 2008, when the Messenger Probe went by.
The second planet from the Sun, and referred to as Earth’s sister plant, Venus is actually nothing like Earth. It is almost the same size as Earth, is covered in clouds of mostly sulphuric acid droplets, and there is little evidence of water on the planet. It has a central iron core and a rocky mantle. Its atmosphere is mainly made up of carbon dioxide and nitrogen, with small amounts of other gases. The average temperature on Venus is 864 °F, which is hotter than Mercury and can melt lead. Venus is 67,237,910 miles from the Sun. Venus is the brightest of the five planets that can be seen in the night sky with the naked eye, and it was probably seen by the first groups of humans.
- The Atmosphere of Venus website provides information about the planet Venus, such as temperature, pressure, and the absence of water.
- Astronomy Course 161 has several pages of information, pictures, and video about Venus.
- Images of Venus Photos and detailed information on the mysterious planet.
Our home is a very unique planet in the solar system. Earth is the only planet that brings together all the necessary elements, in the right amounts, to sustain life. Earth is 92,955,820 miles from the Sun. One day is exactly 23.934 hours and one year is exactly 365.24 Earth days. The coldest temperatures on Earth reach -126 °F, and the hottest temperatures can reach 136 °F. Nickel and iron make up the Earth’s core, and the mantle is made up silicon, iron, magnesium, aluminum, oxygen and other minerals. The next level is the Earth’s crust and is comprised of oxygen, silicon, aluminum, iron, calcium, sodium, potassium and magnesium. Water covers the majority of the surface, with nitrogen and oxygen atmosphere. There are smaller amounts of carbon dioxide, water vapor and other gases also in the atmosphere. There are more than 326 million trillion gallons of water on Earth, including oceans, fresh water, and ice and glaciers.
- The Utah Educational Network provides pictures and information about Earth.
- MIT provides current events regarding Earth, Atmospheric and Planetary Sciences.
- Aerial Photos and satellite images of Earth from space and various other images.
Mars is half the size of Earth and is 141,633,260 miles from the Sun. One day on Mars is equal to 24.62 Earth hours and one year on Mars is equal to 686.93 Earth days. The temperatures on Mars vary from -125 to 23 °F. Mars’s atmosphere is made up of Carbon Dioxide, Nitrogen, Argon. Mars has two moons, Phobos and Deimos. Mars has been known about since the early humans, so no one is credited with its discovery. There is water on Mars, frozen under the north and south polar ice caps. Also, Mars has flood and river channels that suggests liquid water flowed on Mars a long time ago. There is recent evidence that there may also be some liquid water at or near the surface, but this has not been proven. Spacecraft have orbited, or landed on Mars since the 1960’s. In 1976, NASA’s two Viking landers landed on Mars and collected soil, to look for signs of life. So far, no evidence of life has been found. Future missions are being planned to continue the search for life on Mars. These missions will land at different locations and dig deeper into the soil. In 1984, a meteorite from Mars was found by a group of scientists in Antarctica. When studying the 4.5 billion year old meteorite, called meteorite ALH84001, scientists noticed tiny tube-like structures hat looked like fossilized microbial life. This may be proof of past life on Mars. Scientists also saw grains of carbonate minerals, the type which needs liquid water to form. NASA photographs have provided indication that water carried sediment through some of Mars’s gullies sometime during the past seven years.
- Ask An Astronomer for Kids is a great site for all ages, answering questions about planet Earth.
- USGS has a website with many links to images, maps, and other Mars related information.
This is the largest planet in our solar system, and has a total of 62 moons. Jupiter has one ring, which has been broken down into 3 divisions, and is composed of minuscule particles that resemble smoke dust. Jupiter is 483,682,810 miles from the Sun. Its gravity is greater than Earth’s and if a person weighs 100 pounds on Earth, that equals 214 pounds on Jupiter. One Jupiter day equals 9.925 Earth hours. One Jupiter year equals 11.8565 Earth years. The average temperature on Jupiter is -234 °F. It is unknown if a solid surface exists on Jupiter. Jupiter’s clouds are thought to be about 30 miles thick and below that is a 13,000 mile thick layer of hydrogen and helium, which changes from gas to liquid as the depth and pressure increase. Beneath the liquid hydrogen layer is a 25,000 mile deep sea of liquid metallic hydrogen. Jupiter is so large, and visible with the naked eye, that early humans have seen it in the sky and no particular person is credited with its discovery. Europa is the fourth largest moon of Jupiter and Scientists think that life may exist there because of evidence that liquid water might exist beneath its icy surface. Between July 16 and July 22, 1994, several pieces of Comet Shoemaker-Levy 9 collided with Jupiter and was the first collision of two solar system objects ever observed. There is no water on Jupiter.
- An Arizona educational website devoted to Jupiter with awesome images and video clips.
- Windows to the Universe Jupiter Image List provides images of Jupiter and some of its moons.
Galileo Galilei stumbled across Saturn in 1610 when he was looking through his handmade telescope. Saturn is a giant gas planet made up of 94% hydrogen, 6% helium and small amounts of methane and ammonia. It is believed that Saturn has a rocky core about the size of Earth, Saturn has high winds that can reach 1,600 feet per second and in combination with the heat rising from the planet’s interior, yellow and gold bands have formed and are visible in the atmosphere. Saturn’s rings are made of water ice and extend hundreds of thousands of kilometers from the planet. Saturn is 885,904,700 miles from the sun. One year on Saturn equals 29.4 Earth years. One day on Saturn equals 10.656 hours on Earth. The average temperate on Saturn is -288 °F. Saturn’s atmosphere is Hydrogen and Helium, similar to that of Jupiter. Cassini is a satellite that is currently exploring Saturn and its moons. One of the surprises of Cassini’s tour was that the orbiter found a hot spot on the Moon Enceladus, where geysers spew ice crystals. This may be evidence of liquid water below the moon’s surface, a sign that makes Enceladus a prime target for future mission seeking evidence of life beyond Earth.
- Plantary Rings Node website provides information about Saturn and its rings. It includes animations, images, and additional links for information.
- Saturns Moons including photos and detailed information about the moons that orbit Saturn
Astronomer William Herschel discovered the 7th planet from the Sun, Uranus, in 1781. It takes 84 years to complete one orbit and is 1,783,939,400 miles from the Sun. Uranus is tilted almost parallel to its orbital plane and looks like it is sideways. One year on Uranus equals 84.02 Earth years or 30,687.2 Earth days. It has 27 moons. The average temperature is -357 °F, with an atmosphere consisting of Hydrogen, Helium, and Methane. There is no solid surface to stand on. In January 2010, discoveries were made that suggest that Uranus has liquid diamond oceans. Uranus is one of the two Ice Giants because it is made of gases and chunks of ice
- ThinkQuest has a very colorful website with information and pictures of Uranus.
- This is an educational website that provides a lot of pictures and information about Uranus, including its discoverer William Herschel.
- The Rings of Uranus with images of Uranus and its rings.
This was the first planet in which mathematical predictions were used rather than regular observations of the sky. It was discovered in 1846 by Johann Galle. Neptune is 2.8 billion miles from the Sun and a complete orbit takes 165 years. One day is the equivalent of 16.11 Earth hours. The average temperature is -353 °F. Neptune has 13 moons. Neptune is one of the two Ice Giants it is composed of gasses and chunks of ice. . Neptune is composed of a two thirds mixture of molten rock, water, liquid ammonia and methane and the other third is a mixture of heated gases comprised of hydrogen, helium, water and methane. Voyager 2 passed right by Neptune and provided never before seen footage of this giant planet.
- Hands On Universe is an educational website with information on Neptune and its moon Triton.
- This is a valuable website with resources on Neptune and links to lots of pictures and statistics.
Pluto is a very small, cold dwarf planet that was discovered by Clyde Tombaugh in 1930. It is 3,670,050,000 miles from the Sun and doesn’t have much gravity. A 100 pound person would only weigh 8 pounds on Pluto. One year on Pluto is the same as 247.92 Earth years. Pluto has three moons. Pluto is the only planet that has not been visited by a spacecraft. NASA’s New Horizons is expected to visit Pluto in 2015.
- University of Pennsylvania has a webpage geared towards Pluto and its moons.
- Pluto Facts Detailed information about the tiny “planet” of Pluto.
- Harvard University has a website with breathtaking pictures of our solar system.
- The Deep Space Network is a network of antennas that support spacecraft missions, radio and radar astronomy observations and select. Earth-orbiting missions.
- The Extrasolar Plants Encyclopedia is a text heavy compilation of information with up to date statistics of planets that reside outside of our solar system.
- Amazing Space is a website geared towards individuals and teachers and provides information about the plants and beyond.
- The Smithsonian National Museum of Natural History has compelling videos of the solar system, the birth of a planet, and more.