Download Extraterrestrial Volcanism

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.
• http://pubs.usgs.gov/gip/volc/extraterrestrial.
html
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.
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.
ii.
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.