Our little corner of Space

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fact compliments of Bill Arnett

Pre Questions

How did the Solar System form?

What takes up most of the Solar System?

What objects make up the Solar System?

How many planets have we sent probes to, to study?

How the Solar System was Formed

About 4 and 1/2 billion

Years ago a large cloud

of dust in space called a Nebula started to spin and come together. From this nebula our Sun formed. As the sun was forming smaller areas in the nebula began to also spin. These smaller areas swept up matter in the nebula and became the planets and their satellites (moons).

The remaining matter and gasses formed the Comets, asteroids, and meteoroids. Most of the lighter gasses we blown away by solar winds, as the Sun became a main sequence star.

The Solar System is Made of:

The Sun Planets

Asteroids Meteoroids

Comets Satellites

Gasses Dwarf Planets

The Sun

Our Sun is one of billions of stars that make up the Milky Way Galaxy, and is located about 70,000 light-years from the center of the galaxy.

The Sun is a main sequence star and is about 4.6 billion years old.

The Sun makes up 99.9% of all matter in the solar system and supplies the solar system with 99.99% of its energy. The strong gravitational pull of the Sun controls a system of nine planets, and many comets, asteroids, and meteoroids, by keeping them in orbit.

The Planets

Planets are the large bodies that revolve around the sun.

At night they appear brighter in the sky, and tend to change their position through out the year. The name planet comes from the ancient Greeks, which mean wanders. There are eight planets in our solar system.

The Planets are divided into two groups,

the inner planets and

The Inner Planets

The planets that formed closer to the sun lost most of their light gasses, and became hard and rocky.

The four inner planets are located closest to the sun, and are identified by their rocky composition.

The Inner Planets are, Mercury, Venus, Earth, and Mars.

Mercury

Mercury is the planet closest to the sun, and is the smallest of all the planets. Mercury is had to see from Earth because it is so close to the sun.

In 1974 a probe, Mariner 10, first visited mercury. Mariner 10 gave us our first good look at Mercury.

Mercury was found to have many craters, and a fractured crust. It was also discovered that Mercury has very thin atmosphere.

Mercury has a very unique orbit that causes Mercury to have a longer day than year. Mercury spins on its axis slower than it rotates around the sun. This causes Mercury to have daylight for 188 earth days, which is almost twice as long as it’s year. Because the sun shines on one side of Mercury of so long its daytime temperate reaches temperature up to 800° Fahrenheit. Nighttime temperatures due to the long span of time with no sunlight are very cold. Nighttime temperatures can reach as cold as –350° Fahrenheit. No other place in the solar system has temperatures that vary as much as Mercury.

Venus

Venus is the second planet from the sun, and is surrounded by ever-present clouds of sulfuric acid and carbon dioxide. Because of its cloud Venus is the hottest planet in the solar system. Surface temperatures on Venus reach over 800° Fahrenheit, which is hot enough to melt lead. The high temperature is cause by a phenomenon known as the green house effect.

The green house effect is cause when energy from the sun gets trapped by clouds and forms an oven. Light energy is able to pass through the clouds on there way to the surface of Venus but the heat that is radiated from the surface get trapped by the clouds and not allowed to pass through into space.

Venus has been visited by more probes than any other object in space. From these probe we have learned that Venus has a tremendous atmospheric pressure that is so great that it could crush a car if it were parked on the planet.

We have recently learned that Venus has active volcanoes and an almost creator free surface due to constant plate tectonic action of its crust.

Because of its size being very close to earth and having clouds in its atmosphere Venus has been called earth’s twin, but size and clouds about there only similarity.

Venus is also known as the Evening and Morning Star as it is the first object seen at night and the last object seen in the morning. Venus is the third brightest object in the night sky.

Earth

Earth is the third and largest of the inner planets, and the only planet in the solar system we know on which life exists.

Mars

Mars is the last of the inner planets and named after the Roman god of war because of its reddish appearance. The surface of Mars appears red because of the high content of iron in its soil.

Of all the planets Mars is the closet to being like Earth. Because of Mars’ distance from the sun its temperatures are the most suitable for life other than Earth.

High temperatures on Mars can reach as high a 80° Fahrenheit at its equator and low temperatures below -100° Fahrenheit at its polar regions.

Mars has a day that is closest to Earth’s. A day on Mars is equal to almost 24 hours.

Mar has an atmosphere similar to Earth but with less amounts

There is evidence that Mars once had liquid water. Mars has a canyon system larger than the Grand Canyon that was carved by water millions of years ago.

Today there is no liquid water on the surface of Mars the water is frozen in its polar Icecaps and in its crust.

Mars was discovered to have had active volcanoes long ago. Olympus Mons was discovered on Mars in the 1970’s and is the largest Volcano in the solar system.

For many years Mars has been the focus of stories of intelligent life. Many books and movies have been produced about Aliens coming from Mars and attacking the Earth, but this fiction. Astronomers are actively searching for life on Mars but do not feel they will find the necessary evidence until Earth sends a manned mission to Mars. A manned mission to Mars is planned for the future and will be a joint mission between the United States and Russia.

Asteroid Belt

A region known as the Asteroid Belt separates the Inner and Outer planets. Between the inner and outer planets is an area known as the asteroid belt.

This is an area where over 100,000 asteroids revolve around the sun.

Asteroids are large rocky objects orbiting the sun. Asteroids can be as large as the state of Texas.

Asteroids are sometimes called minor planets.

The Outer Planets

The Outer Planets are much different from the inner planets. The outer planets are very large and gaseous. All of the outer planets have many satellites, and rings, except Pluto that has only one satellite and no rings,

Jupiter

After crossing the Asteroid Belt we come to the first of the large Gas Giant planets, Jupiter. Unlike the inner planets, which have thin atmospheres and hard rocky surfaces, the outer planets have very thick atmospheres that hide their surfaces from our view.

Jupiter is the largest of the outer planets, and so massive that it is more massive that all of the other planets combined.

Like all the large outer planets Jupiter has a very thick atmosphere composed mostly of hydrogen gas. Jupiter is made up of much of the same gasses as the Sun. If Jupiter would have been larger it could have become a small star.

The atmosphere of Jupiter is arranged in bands of clouds that rotate very rapidly around the planet. Only the upper portion of Jupiter’s atmosphere is visible to telescopes. Images from probes sent to Jupiter show that Jupiter’s atmosphere is very turbulent and full of storms.

The largest of Jupiter’s storms is known as the Red Spot, and is Jupiter’s most famous feature. Galileo first observed this red spot almost 300 years ago.

In 1979 Jupiter was discovered to have a very thin system of rings orbiting around its equator. Jupiter also has 60 or more satellites the most in the solar system; some, which are, believe to be captured asteroids from the Asteroid Belt.

Of the numerous satellites four were discovered over 300 years ago by Galileo, they are Callisto, Ganymede, Europa, and Io. Probes have studied these, the largest of Jupiter’s satellites, and found them to be very dynamic. Probes discovered active volcanoes on Io, and that Europa is covered by a layer of ice under which is liquid water.

Saturn

Saturn is the sixth planet from the Sun and second of the large gas giants. Saturn is second in size to Jupiter and is comprised mostly of the same gases, and like Jupiter, Saturn’s has bands of clouds rotating around the planet. Saturn’s also has storms in its atmosphere and probe have captured thunder and lightning in its atmosphere.

Up until 1979 Saturn was the only planet known to have rings but now it is known that all of the large outer planets have systems of rings.

Saturn is the planet known for its elaborate ring system and has often been called the jewel of the solar system. For hundreds of years Saturn was thought to have four large rings but probes to Saturn have found the rings to be thousands of intricate rings of ice particles.

Astronomers are not quite sure what may have caused Saturn’s rings or the other rings of planets, but the rings are thought to have been from a satellite that either broke up from Saturn’s gravitational pull or remnants from a satellite that never formed.

Saturn like all of the gas giant outer planets has a system of 50 or more satellites. Of Saturn’s many satellites Titan is its largest and the largest satellite in the solar system. Titan has been observed since 1655, and is know to have an atmosphere of Nitrogen similar to Earth’s. But because of Titans great distance from the Sun, astronomers feel that Titan would be to cold to support life.

A new discover on Saturn is that there is a large hurricane like storm at Saturn's south pole. click for image

Uranus

After Saturn planets can only be seen with telescopes. Sir William Herschel a German-English musician and astronomer discovered Uranus in 1781.

Not as much is know about Uranus and the rest of the outer planets due to the fact that only one probe has visited these far and distant planets. What we do know is that like Jupiter and Saturn Uranus is a large gas giant, about half the size of Saturn. Uranus has 20 or more satellites and a system of rings. And is composed mostly of gas. Hydrogen and helium are the most dominant gas in Uranus’ atmosphere. An abundance of Methane gas gives it a blues color.

Unlike the rest of the planets Uranus’ does not spin around its polar axis in a vertical manner, but rather rotates horizontally that gives Uranus the appearance of rolling in space around the Sun.

Neptune

Neptune, the eighth planet from the Sun, is a very cold place. Unlike the inner planets, the farther distant outer planets give off more energy than they receive from the Sun. From Neptune the Sun looks like a larger bright dot in the night sky.

Neptune was not discovered about 1846 but it was not discovered because someone noticed it in the sky. While attempting to plot Uranus’ orbit astronomers noticed that the orbit they calculated did not agree with the actual orbit they observed.

Therefore astronomers concluded that another planet must exist beyond Uranus. So French astronomer Leverrier and British astronomer John Couch Adams calculated Neptune’s location, and using the calculated location of Neptune German astronomer Johann Galle made the first observation the planet.

Neptune was found to be very similar to Uranus in size and appearance, and therefore nicknamed Uranus’ twin.

Neptune’s atmosphere is the same composition as Uranus and also appears bluish in color. Voyager II probe discovered a large blue spot in the atmosphere of Neptune that behaves similar to the Red Spot on Jupiter.

Neptune was also discovered to have a thin ring system and 10 or more satellites. One very large satellite Triton was discovered in 1846 along with Neptune.

Kepler Belt Objects

Pluto and Dwarf Planets

In the August of 2006 astronomers around the world debated on the fate of Pluto’s status as a planet. For many years Pluto’s status as a planet has been under debate because of it’s odd ball characteristics compared to the other 8 planets and great difference from the other outer planets. In the 1990’s astronomers started to find more Pluto like objects. Some of the object astronomers found such as Eris is even larger than Pluto. The name given to these new found objects is dwarf planets.

Because Pluto had more similarities to these new found dwarf planets many astronomers wanted Pluto be down graded from a planet to a dwarf planet. During summit of the IAU (International Astronomical Union) in 2006 astronomers formed a definition of a planet. According to their definition, a planet is a body that orbits the Sun, is large enough for its own gravity to make it round, and has "cleared the neighborhood" of smaller objects.

“Those objects which orbit the Sun and are round by self-gravity, yet have not cleared the neighborhood around their orbits are termed dwarf planets. This definition caused Pluto to be classified as a dwarf planet, the official number of "classical" planets has fallen from the traditional nine to eight.”

Now instead of being a planet Pluto has become a member of the Kepler Belt.

The Kepler Belt is an area in our solar system extending about 120,000,000 miles beyond Neptune. In the 1930 astronomers began to suggest that there existed an area out beyond Neptune where short orbit comets existed. Around this same time Clyde Thombaugh discovered Pluto a large Planet like object

So what do we know about Pluto? We know that Pluto is a very cold due to its great distance from the Sun. In 1979 a satellite, Charon, was discovered near Pluto. The discovery of Pluto’s satellite decreased the calculated size of Pluto to a diameter of only 1,430 mile.

Pluto has a unique orbit that is tilted from the orbits on the other 8 planets. Pluto’s unusual orbit crossed the orbit of Neptune.

For 20 yeas of its orbit around the Sun Pluto is closer to the Sun than Neptune. This last happened in 1979. On February 7^th1999 Pluto once again move out beyond Neptune.

The New Horizon probe was sent to study Pluto in January of 2006 but will not arrive at Pluto until 2015.

Comets

Comets are lumps of ice and rock that periodically come into the center Most of the comets in solar system come from an area of the solar system called to Oodt Cloud, which is a large cluster of millions comets out beyond the orbit of Pluto. Astronomers believe that comets are the remains of the original matter of the solar system, and therefore astronomers believe that comets contain much information on the origin of the solar system.

Comets are made of frozen water and gases mixed with other solids. The structure of a comet is a hydrogen corona around a coma of dust particles that surrounds a nucleus. Streaming from the Coma is a dust tail and a gas tall. The tail of a comet appears when a comet approaches the Sun. Energy from the Sun melts the nucleus forming the Coma, and then pushes the Coma into a tail. The tail of a comet always points away from the Sun.

Comets have been the view observed for thousands of years, and often the product of superstition. For many year comets were believed to be the bringers of bad fortune. The comet Halley’s was observed in 1066 AD and blamed for the fall of the King of England.

The Comet Halley’s is named after the Astronomer Edmond Halley who first suggested that comets were natural occurring phenomenon of the solar system. Halley suggested that the comet he observed (Halley’s Comet) had been observed since 240 BC and would be observed every 76 years. Halley’s Comet was last observed in 1986 and will return again in 2062.

Some recent comets to be view in the northern hemisphere were Hyakutake in 1996 and Hale-Bopp in 1997.

Meteoroids, Meteors, Meteorites

Interplanetary space is littered with meteoroids, "rocks" tens of yards in diameter and less. These objects from time to time cross the path of planets and get caught in the planets gravitational put and fall through the planets atmosphere leaving a fiery trail of light before the burn up, or strike the ground.

As meteoroids strike the Earth's atmosphere at high relative speeds, they leave visible trails known as meteors or, more poetically, "shooting stars".

The meteors are created when the intense heat caused by friction vaporizes the interplanetary traveler. Meteoroids weighing small fractions of an ounce that do not survive to reach the ground can cause fireballs.

Remnants of Larger meteoroids, which do reach the ground after running this fiery gauntlet, are called meteorites.

No person has been killed in modern times by a meteorite, at least not in the authenticated records. In 1511, folklore has it that a meteorite in Cremona, Italy killed a monk.

Animals have been less fortunate. In 1860 in Ohio a calf was killed, and in 1911 a meteorite killed a dog in Egypt.

On November 30, 1954 a 3-pound meteorite that crashed through the house of Anna Hodges, of Sylacauga, Alabama, striking her while she was resting on her living room couch struck. Mrs. Hodges was not killed but the meteorite left a severe bruise. The odds of being hit by a meteorite are 10 trillion to 1.