Brightly glowing lava from the volcano Pele is seen in this image taken by NASA's Galileo spacecraft as it receded from its close flyby of Jupiter's moon Io in October, 1999. The image at left shows Io's surface in approximately true color, centered on the large red ring of sulfur that was deposited by Pele's plume and reaches more than 1,300 kilometers (808 miles) in diameter. A false color infrared composite of the same region is shown on the right. The dark red dot at the center of the ring (seen in the false color picture) is the glow of hot lava at the heart of the volcano. Temperatures up to 1,027 degrees celsius (1,880 degrees fahrenheit) have been previously measured for Pele's lava. The glow is bright enough to be imaged in daylight, allowing scientists to precisely pinpoint the eruptive center.
 

This page has a variety of links to videos with sound. 

	Mercury	Venus	Earth	Mars	Jupiter	Saturn	Uranus	Neptune	Pluto
diameter ( Earth=1 )	0.382	0.949	1	0.532	11.209	9.449	4.007	3.883	0.180
mass ( Earth=1 )	0.055	0.815	1	0.107	318	95	15	17	0.002
average distance from Sun ( AU )	0.39	0.72	1	1.52	5.20	9.54	19.18	30.06	39.44
time to orbit Sun ( in Earth years )	0.24	0.62	1	1.88	11.86	29.46	84.01	164.8	247.7
length of day ( in Earth days )	176	117	1	1.03	0.41	0.44	0.72	0.67	6.38
temperature at surface ( C )	-180 to 430	465	-70 to 55	-120 to 25	-150	-180	-210	-210	-220
gravity ( Earth=1 )	0.38	0.9	1	0.38	2.64	0.93	0.79	1.12	0.04
number of moons	0	0	1	2	16	18	15	8	1
rings	no	no	no	no	yes	yes	yes	yes	no

 

The Inner Planets:
The inner, or Terrestrial, planets are: Mercury, Venus, Earth, and Mars. They are small (because of multiple collisions during their formation) rocky planets with an atmosphere without primordial hydrogen and helium due to their small gravitational pull.

1. Mercury:The closest planet to the Sun.

 

2. Venus: Our Sister planet.
         
The most detailed radio map of the planet was made by the Magellan space-craft, which clearly shows that Venus has an active volcanic surface with mountains.
 

3. Earth: Our Home!
 
The interior of the Earth consists of four layers:

•       An inner core, which is solid metal;
•       A liquid core, which is molten metal;
•       A mantle, which behaves almost like plastic;
•       A crust, which is divided into two kind of plates: Oceanic and Continental.

Moon: Our only satellite.

Besides the Earth in which we live, the only other celestial body in which humans have landed is the the moon; the first landing took place on July 20, 1969 by the Apollo 11 crew.
 

4. Mars: The red planet.
   
                                              Huge canyon Valles Marinaris (4000km long).

Huge volcano: Olympus Mons (24km high).

Mars' red color is due to Iron Oxide on its surface. Mars is about half the size of the earth, it has two moons (Phobos and Deimos) and and a very large canyon on its surface. It has a thin cold atmosphere and evidence for ice water on the polar caps. The role of liquid water (in the form of dry river beds) on possible life on Mars in the past ... is still unknown. 
 

The Outer Planets:
The outer, or Jovian, planets are: Jupiter, Saturn, Uranus, and Neptune. They are massive (at least 15 times as massive as the Earth) gaseous planets with atmospheres rich hydrogen, helium, and other gases.

5. Jupiter: The titan of the planets. 

Jupiter has a very similar composition as our Sun; it consists mainly of hydrogen and helium. There are very large structures on its surface, such as the Great Red Spot which are due to the convective flow of gas. Jupiter also has a strong magnetic field and magnetosphere. Until now, 16 moons have been observed in Jupiter, with the four largest known as the Galilean moons:

1. Io See also this videoclip for Io.
2. Europa
3. Ganymede
4. Callisto

6. Saturn:  The quintessential of the planets. 

Saturn is the second largest planet in our solar system. Saturn has similar constitution to Jupiter; its surface has zones of rings and belts. It has a beautiful ring system which is visible by a telescope. This ring system was probably formed in the early stages of our solar system formation.
 

7. Uranus: The tilted planet.

Uranus rotates on its side, with its axis tilted 98 degrees relative to its axis of revolution around the Sun. Because Uranus is so far away from the Sun (19 AU) the length of its year is 84 years. Thus, each of its very peculiar seasons last about 20 years. For example, during the summer, the southern hemisphere receives no light for almost 20 years! Uranus is now known to have 15 moons.The most famous and largest of its moons is Miranda.
 

8. Neptune: The windy planet.

Neptune was observed closely by Voyager II in 1989. The largest feature observed was the Great Dark Spot, roughly the size of Earth. Neptune displays a violent and changing atmosphere with some of the strongest winds ever recorder in the Solar System. Indeed, its atmosphere is so dynamical that recent photographs of the HST show no evidence of the Great Dark Spot. Neptune is similar in composition to its neighbor Uranus and has an interesting ring system.  It also has one of the largest moons in our solar system: Triton. Triton has an interesting atmosphere an structure. Neptune was discovered on purely theoretical grounds on the basis of the "disobedient" motion of its neighbor Uranus.
 

9. Pluto: The "odd-man" out.

Pluto is - most of the time - the most distant planet in the Solar System. Pluto is also peculiar in that it does not fit the general classification of inner nor outer planets. Moreover, its orbit around the Sun is tilted by more than 17 degrees relative to the the plane of the ecliptic. This is a large deviation from the orbit of the other planets.