Sun & Planet Facts
The Solar System is comprised of one star-the Sun, eight known planets, the newly classified "dwarf planets", thousands of asteroids, comets, and meteoroids. There are many web sites that will provide you with very detailed information concerning all of these subjects. Here we provide you with some basic statistics to get you started.
Page Index: Sun / Mercury / Venus / Earth / Moon/ Mars / Asteroids / Jupiter / Saturn / Uranus / Neptune / Pluto / Quaoar & the Kuiper Belt / Comets / Sedna / Eris
Off Site Solar System Links:
JPL Solar System Page / The Nine Planets / Hubble Space Telescope
What is a Planet? This question was officially answered in August 2006 by the International Astronomical Union, a world-wide group of astronomers who are the accepted sanctioning body for naming and classifying objects discovered in space. They offically defined a planet as any object that orbits a star, is large enough to be round, and has enough gravity to clear its orbit of smaller debris.
What is a "Dwarf Planet?" The IAU also created a new classification of solar system objects known as "Dwarf Planets", these would be objects that orbit a star, are large enough to be round, but not have enough mass (and therefore gravity) to clear its orbit of debris.
Under the new guidelines, Pluto is no longer a planet, instead it falls into the category of being a Dwarf Planet because it lies within the Kuiper Belt of thousands of icy asteroid like objects. Other solar system objects that are likely to fall into this new category might be Ceres (the largest asteroid), Quaoar, Sedna, and Eris formerly known as 2003UB313 (Xena).
For more information regarding this new classification system check out the following links:
Check out Scrolling
Through The Solar System and discover how
far apart the planets really
are!
SUN Rotates: 26 days. Surface Temp: 12,000°F (6000°C) Core Temp: 27 Million°F (15 Million°C) Diameter: 865,000 mi. (1,395,161 km). Density: 1.41. Mass=333,000 Earths. A middle aged (4.5 Billion yrs. old) average sized star. It's outer atmosphere "the heliosphere" extends beyond Pluto.
The Sun /
SOHO / The
Nine Planets / Ulysses
Probe to the Sun / Genesis
Mission
The Virtual
Sun
MERCURY Rotates: 58 days 16 hours. Revolves: 88 days. High Temperature: 700°F (350°C) Low Temperature: -270° F (-170° C). Diameter: 3,031 miles. (4,878 km.) Density: 5.4. Mass=0.06 Earths. Gravity: 0.38 X Earth's. No moons or rings. Mercury was visited in 1974 by the Mariner 10 Space Probe and about 45% of the planets surface was photographed. It's surface is dominated by impact craters. The largest crater is called the Caloris Basin which measures 810 miles (1,300 km) in diameter. Lacking in mountains, Mercury's other dominant type of feature are scarps. Scarps are long cliffs formed by a contracting crust when the planet cooled. The largest scarp is called "Discovery Rupes" and is about 310 miles (500 km) long and about 2 miles (3 km) high.
Solar System Index / Northern Stars Explorations Page
VENUS Rotates: 243 days. Revolves: 224.7 days. Average Temperature: 900°F (480°C) Diameter: 7,541 miles. (12,104 km.) Density: 5.2. Mass=0.8 Earths. Gravity: 0.9 X Earth's. Thick Carbon Dioxide (CO2) atmosphere. No Moons or rings. Venus has clouds of sulfuric acid. It has nearly 90 times more atmosphere than Earth. Named after the Roman Goddess of Love and Beauty. It is believed that it may rain sulfuric acid on Venus, but due to the high temperatures the rain evaporates before reaching the surface.
Solar System Index / Northern Stars Explorations Page Off Site Venus Links:
EARTH Rotates: 23 hours. 56 minutes. Revolves: 365.25 days. High Temperature: 130°F (58°C) Low Temperature: -126°F (-88°C). Gravity: 1 X Earth's. Diameter: 7,927 miles. (12,756 km.) Density: 5.5. Mass=1 Earth. Nitrogen & Oxygen atmosphere. 1 moon, no rings. Earth is dominated by water which covers three quarters of it's surface area.
THE MOON Rotates:27 days, 8 hours. Revolves: 27 days, 7 hours. 43 minutes. (when measured in relationship to the stars) or 29 days, 12 hours. 44 minutes. (when measured in relationship to the Earth and Sun--this is the amount of time from one full moon to the next). High Temperature: 214°F (101°C) Low Temperature: -300°F (-184°C). The poles seem to have a near constant temperature of -140°F (-96°C). Diameter: 2,155 miles (3476 km). Density: 3.34. Evidence of water ice has been found deep in some craters near the moon's poles. Twelve astronauts have walked on the moon's surface between 1969 and 1972.
Solar System Index / Northern Stars Explorations Page Off Site Moon Links:
Apollo 11 / Clementine Probe / Lunar Prospector / The Nine Planets
Google Moon / Inconstant Moon
MARS Rotates: 24 hours. 37 minutes. Revolves: 1,88 years. High Temperature: 80°F (27°C). Low Temperature: -190°F (-123°C). Diameter: 4,197 miles. (6,794 km). Density: 3.9. Mass=0.1 Earths. Gravity: 0.38 X Earth's. Thin Carbon Dioxide atmosphere. 2 moons, no rings. In 1996 scientist found possible evidence of fossilized bacteria in a meteorite believed to have originated on Mars--perhaps long ago Mars had life! Mars has a canyon named Valles Marineras that would stretch from Maine to California if it were found on Earth. It also has the largest and tallest volcanoes in the solar system.
Solar System Index / Northern Stars Explorations Page Off Site Mars Links:
Mars Exploration (all active probes) / Mars Rovers
Mars Pathfinder / Mars Global Surveyor
Hubble Space Telescope Pictures / The Nine Planets
Mars Odyssey / Mars Express / Mars Reconnaissance
ASTEROIDS Between Mars and Jupiter is a region of the solar system known as the asteroid belt. Thousands of asteroids have been catalogued. The asteroid pictured here, named Gaspra, was the first asteroid seen up close by a space probe, the Galileo Probe to be exact.
Galileo Probe /
The
Nine Planets / /
Malin Space
Science System's NEAR Page / Near
Shoemaker Probe
Muses-C
Mission
JUPITER Rotates: 9 hours. 48 minutes. Revolves: 11.86 years. Cloud top Temperature: -140°F (-95°C) Diameter: 88,733 miles. (142,796 km.). Density: 1.3. Mass=318 Earths. Gravity: 3 X Earth's. Composition: Mostly Hydrogen, Helium. 63 moons, 1 small ring. Jupiter has a huge storm called the Great Red Spot that has been blowing about on Jupiter for hundreds of years. In 1994 Jupiter was hit by Comet Shoemaker-Levy 9.
Comet Shoemaker Levy 9 Impacts Jupiter /
Galileo Probe / Galileo Fun Stuff / Hubble Space Telescope Pictures /
SATURN Rotates: 10 hours. 39 minutes. Revolves: 29.46 years. Cloud top Temperature: -292°F (-180°C) Diameter: 74,600 miles. (120,000 km.). Density: 0.7. Mass=95 Earths. Gravity: 1.32 X Earth's. Composition: Mostly Hydrogen, Helium. 56 moons. It has a large ring system.
Hubble Space Telescope Pictures / Voyager / The Nine Planets
URANUS Rotates: 16 hours. 48 minutes. Revolves: 84 years. Cloud top Temperature: -346°F (-210°C). Diameter: 31,600 miles. ((50,800 km.). Density: 1.3 Mass=14.5 Earths. Gravity: 0.93 X Earth's. Composition: Mostly Hydrogen, Helium, some ammonia, methane. 27 moons, about a dozen thin rings. Uranus is tipped on its side by 98°.
Hubble Space Telescope Pictures / Voyager / The Nine Planets
NEPTUNE Rotates: 16 hours 3 minutes. Revolves: 164.8 years. Cloud top Temperature: -364°F (-220°C). Diameter: 30,200 miles. (48,600 km.). Density: 1.6 Mass=17 Earths. Gravity: 1.23 X Earth's. Composition: Mostly Hydrogen, Helium, some methane and ammonia. 13 moons, 3 thin rings, 2 broad rings.
Hubble Space Telescope Pictures / Voyager / The Nine Planets
PLUTO Rotates: 6 days, 9 hours. Revolves: 248 years. Temperature: -400°F (-238°C). Diameter: 1900 mi. (3,000 km.). Density: 2. Mass=0.002 Earths. Gravity: 0.03 X Earth's. Has a very thin atmosphere. 3 moons, no rings. The largest moon, Charon, is half the size of Pluto, some scientists refer to Pluto & Charon as a "Double Planet." Pluto's orbit is very elliptical and tilted; it actually crosses inside Neptune's orbit from 1979-1999.
Pluto was officially reclassified in August 2006 as no longer an official planet, instead it joins the ranks of dwarf planets
Solar System Index / Northern Stars Explorations Page
Off Site Pluto Links: Hubble Space Telescope Pictures / New Horizons Probe / The Nine Planets
QUAOAR & THE KUIPER BELT Quaoar is approximately 800 miles in diameter and is slightly farther away from the Sun than Pluto. It is made primarily of ices. It is the largest known object in the Kuiper Belt (other than Pluto!). The Kuiper Belt is a band of icy objects just beyond the orbit of Neptune; similar to the Asteroid Belt, the Kuiper Belt is made of objects too small to be labelled as planets. Both Quaoar and Pluto reside within the Kuiper Belt.
Solar System Index / Northern Stars Explorations Page
Off Site Quaoar Links:
ERIS (formerly known as 2003 UB 313 or Xena) was first photographed in October 2003, but was not detected until January 2005. Its discovery was announced in August 2005. This object is larger than Pluto and currently about three times farther away from the Sun than Pluto. It may soon be officially classified as the 10th planet. It does not yet have an official name, that will come soon. It is made of ices, much like Pluto. It takes this new planet 557 years to orbit the Sun just once. Its orbit is tilted nearly 45 degrees up at an angle compared to the plane of Earth's orbit. Recently scientists announced the discovery of a moon orbiting Xena, it has been nicknamed "Gabrielle."
SEDNA Sedna is the most distant object yet discovered in the solar system. It was discovered in 2003. It is roughly three tumes further away than Pluto, well outside the Kuiper Belt. It is approximately 1000 miles in diameter and takes nearly 10,500 years to go around the sun just once. Currently, scientists have not officially classified it as the tenth planet, if that does happen, Sedna would become the smallest planet, the coldest planet, and the most distant planet! Sedna was named after an Inuit Goddess of the Sea.
Solar System Index / Northern Stars Explorations Page
Off Site Sedna Links:
COMETS Comets are comprised of a ball of ice, snow, rocks, and pebbles that orbit the Sun in highly elliptical (oval) orbits. The "dirty snowball" can vary in size from a couple of miles in diameter to perhaps 25 or 30 miles in diameter. The Sun's radiation and solar wind melts the outer layers of icy materials to form the "Coma" which is sort of like a fog bank that engulfs the nucleus (snowball). The coma might be as much as 100,000 miles in diameter. The coma is then pushed away from the sun by the solar wind to form the comet's tail. Comets have two basic tails, an Ion or Gas Tail and a Dust Tail.
Solar System Index / Northern Stars Explorations Page
Off Site Comet Links: Comet Observation Page / Comet Shoemaker Levy 9 Impacts Jupiter /
StarDust Probe to a Comet / Deep Impact Probe / Rosetta Mission
METEOR SHOWERS are covered on their own page.
Off Site Solar System Links that will provide you with good basic information:Astronomical Society of the Pacific / Astronomy / The Jet Propulsion Laboratory /
NASA / The Nine Planets / The Planetary Society / Sky and Telescope / The Solar System Live /
National Geographic's Virtual Solar System / Merlot
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