Chapter 7.3

1.Many people believe that planets and moons outside of Earth are inactive. However, these people are wrong. a.Evidence has shown that many other planets and moons are currently active or at have been in the past. b.Mars, Earth’s moon, and Io (a moon of Jupiter) are three examples.

c.Through space exploration, evidence has been transmitted back to Earth from satellites and mobile vehicles stationed on mars that there may be volcanism occurring on the planet. d.Numerous images have been sent back to Earth showing volcanos and volcanic features.

i.Olympus Mons is the largest of the discovered volcanos on mars. 1.It is 28km tall, 600km across at the base, and 70km across at its caldera. 2.One theory explaining why this volcano grew so large is that Mar’s crust does not drift like Earth’s. Therefore, this volcano stayed over the lava source and continued to grow for, possibly, millions of years.

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c.While the question as to whether or not is Mars active is still unanswered, much of the evidence suggest that it is. i.The Viking landing craft detected two geological events that produced waves similar to Earth’s earthquakes. ii.This evidence is suggestion for volcanic activity on Mars.

1.Earth’s Moon a.Evidence that the Earth’s moon was active in the past. i.The near side of the moon is covered with ballistic lava flows which is evidence that the moon’s surface had many active volcanos.

ii.Craters on the moon’s surface are a result of meteorite bombardment. iii.Deep basins on the moon, called maria, were once filled with lava.

b.While this evidence suggest activity on the moon, many questions have also been create. For instance: i.There is no evidence of plate tectonics or convection currents in the moon, so how is magma formed in the lunar interior and how did it reach the moon’s surface? 1.One theory suggest that this thermal energy came from intense meteorite bombardment.

1.Io: One of the many moons of Jupiter a.The first planetary body, other than Earth, that active volcanoes have been sighted. b.The Voyager 1 & 2 spacecraft’s sent images to Earth showing nine erupting volcanoes on Io. This was in 1979.

c.Io is approximately the size of Earth’s moon and is the most volcanically active body in the solar system that we know of.

d.Scientists believe that the amount of volcanic material ejected onto Io’s surface is several thousand metric tons each second. The amount of volcanic material to cover Io’s surface every month is similar to a single eruption of Mount St. Helen’s eruption in 1980.

e.The volcanic material erupting on Io are neither felsic nor mafic. Scientists believe they are primarily made up of sulfur and sulfur dioxide due to the color.

f.Scientists believe that this thermal energy is the result of the in and out motion of the surface of Io which is caused by the gravitational pull of Jupiter and the many other moons of Jupiter.