The words solar system refer to the Sun and all of the objects that travel around it. These objects include planets, natural satellites such as the Moon, the asteroid belt, comets, and meteoroids.    The Sun is the center of the solar system. It contains 99.86% of all of the mass in our solar system. Consequently, it exerts a tremendous gravitational pull on planets, satellites, asteroids, comets, and meteoroids.

Big Bang Theory

A theory of cosmology in which the expansion of the universe is presumed to have begun with a primeval explosion
(referred to as the "Big Bang").

Scientific methods are useful tools for the study of earth science.  However, the development and testing of a hypothesis is just one step along the way to scientific understanding.  Once a hypothesis  has been tested and generally accepted, it may lead to the development of a THEORY.   A theory is a hypothesis or a set of hypotheses that is supported by the results of experimentation and observations that is consistent with known facts.
Once a theory is well established through research and experimentation, it may become a scientific law.  A scientific law is a rule that correctly describes a natural phenomenon.  To become a law, a theory must be proven correct every time it is tested.  For example, the law of conservation of mass and energy, which states that the total amount of matter and energy in the universe does not change, has been tested again and again.  It has never been found to fail.  View the Physical Science page for more information on Newton's and Kepler's Laws.

The Sun

Photo courtesy SOHO consortium. 

SOHO is a project of international cooperation between ESA and NASA.

"ERUPTION: Magnetic fields above giant sunspot 652 erupted on July 22nd (0032 UT), and Jack Newton of Arizona photographed the event, which ranked M9 on the Richter Scale of solar flares. Says Jack, "the sunspot looked like a giant river of lava during the explosion" ". (Space Weather.com, 2004).

This eruption emits something called coronal mass ejections into space which can effect Earth's magnetic field.  When this happens we notice glitches in electrical equipment, like cell phones, TV reception, medical equipment, and the like.

Electromagnetic Spectrum

The  rainbow is really a continuous spectrum that shows us the different energies of light (from red to blue) present in visible light. But the electromagnetic spectrum encompasses more than just optical light - it covers all energies of light extending from low-energy radio waves, to microwaves, to infrared, to optical light, to ultraviolet, to very high-energy X- and gamma-rays.

Visible Light

Acronyms like "ROY G BIV"  help us to remember the spectrum in order. 

700 nm                                                                                                   400nm

Red          Orange          Yellow           Green            Blue          Indigo         Violet

The rainbow is really a continuous spectrum that shows us the different energies of light (from red to blue) present in visible light. But the electromagnetic spectrum encompasses more than just optical light - it covers all energies of light extending from low-energy radio waves, to microwaves, to infrared, to optical light, to ultraviolet, to very high-energy X- and gamma-rays.

White light is the combination of red, blue and green light.  As seen in the image above, adding different combinations of light, like red and blue to make magenta, will display varied frequencies of the light spectrum.

Plants respond differently to frequencies (or colors) of light. This is why we use a plant grow light in the classroom terrarium.

This shot taken in Melbourne, FL  March 2007;  66 minutes of exposure taken over 2 nights

Doppler Effect & Waves

Magnetic Field

All magnetic objects produce invisible lines of force that extend between the poles of the object.  Earth and Jupiter can be thought of as a dipole (2-pole) magnet.  Magnetic field lines radiate between Earth's north and south magnetic poles just as they do between the poles of a bar magnet. Charged particles become trapped on these field lines (just as the iron filings are trapped), forming the magnetosphere.  Jupiter is also surrounded by an enormous magnetic field called the magnetosphere, which has a million times the volume of Earth's magnetosphere. Charged particles are trapped in the magnetosphere and form intense radiation belts. These belts are similar to the Earth's Van Allen belts, but are many millions of times more intense.
 

Northern Lights in the Ionosphere

*  Visible manifestation of the high-energy electrons
*  Reds and greens of oxygen and hydrogen and the purples and pinks of nitrogen
*  Typical 3-hour aurora discharges about 100 million kW hours of electric energy
*  Enough energy to power a medium sized city of 250,000 for nearly 9 days
*  = about 6 days of energy output by large nuclear power plant

Our Solar System

Inner and Outer Planets

 
  Sun
Mercury
Venus
Earth
Mars
Meteor Belt
Jupiter
Saturn
Uranus
Neptune
(Pluto)

Obliquity of the (Nine)  Eight Planets

Weight vs. Mass

Weight is a force, it is the pull of Earth's gravity on an object. While weight of an object is a force, the mass measures inertia. An object's weight changes if the pull of gravity changes, but an object's mass is the same everywhere in the universe. If air resistance were not a factor, everything near the Earth's surface falls with acceleration g, so weight = mg.

Try this ...

Your Age and Weight on Other Planets

Earth's Seasons

Each season -- spring, summer, autumn and winter -- lasts about three months and brings changes in temperature, weather and the length of daylight. The seasons keep changing because the tilt of the Earth's axis never changes while the earth circles the sun.

 
 

Phases of the Moon

The different shapes of the moon through the month are called phases.  During these phases the moon doesn't change shape, we just see different parts of the lighted half of the moon.  With the exception of during an eclipse, when the earth's shadow covers the moon, the sun always lights half of the moon.  That's just like the sun lighting half the earth, giving us day and night.  The moon orbits around the earth approximately once every 29.5 days.  If the moon is between Earth and the sun, we don't see the "daylight" half because the moon is facing the sun.  The moon looks dark to us during this phase, which is called a "new moon."  If the sun is on one side of Earth, and the moon on the other, we see the entire lighted face of the moon, referred to as  a full moon, when planets are in "opposition".  The other phases are just the places in between these positions when we see just part of the moon's day.  Try the activity below and test your skill.