EXPLORING OF IO’S VOLCANOES
Yulia Desislavova Yancheva, student of 9th grade, IV High school for foreign languages
Frederic Joliot-Curie, Varna, Bulgaria
Pavel Peychev Popov, student of 9th grade, Mathematics high school Dr. Petar Beron, Varna,
Bulgaria
Teacher: Eva Stefanova Bojurova, Astronomical observatory and Planetarium Nicholas
Copernicus, Varna, Bulgaria
Jupiter’s satellite Io has the highest volcanic activity in the Solar system. Its volcanoes are photographed by
several space probes for short intervals of time. Based on these frequently erupting volcanoes however, we can quickly
obtain a lot of information and create methods for predicting the eruptions of the terrestrial volcanoes as well.
Using measurements on Io’s images we determine the heights of the jets ejected by the volcanoes. Knowing
the mass and the radius of the satellite, we estimate the initial velocities of the ejected particles. Similarly we estimate
the initial velocities of the material ejected by some volcanoes on Earth and by the geysers of Saturn’s moon
Enceladus. We try to explain the rings formed by the ejected material around Io’s volcanoes. We explore the ratio of
diameter of the area within which the material is scattered, to the height of the jets. We compare the observed ratio
with the theoretical value deduced by us.
Our results show that the velocities of the ejected material are of one and the same order of value for the three
space bodies. So, we believe that at least some of the conclusions ensuing from the investigation of the space
volcanoes can be valid also for the volcanoes on Earth.
Finally we propose an idea for exploration of Io’s volcanoes by means of two space probes in orbit around the
satellite, designed for obtaining stereo images. We present a set of interesting scientific tasks that will be fulfilled by
the space probes.
Introduction
Volcanoes provoke both our fascination and fear; volcanic eruptions on Earth have caused a
multitude of global catastrophes and dead of numerous living creatures, destruction of whole cities.
Exploration of volcanoes is exceptionally important for finding methods that will enable us to
predict eruptions and prevent such disastrous surprises for the Earth in the future. Having in mind
the real thread for all the mankind of probable eruptions of super volcanoes like Yellowstone, that
can lead to mass and global consequences for the whole planet, it would be useful for us to have
more knowledge about volcanoes, so that we could reduce the consequences of their activity to a
minimum.
The object with doubtlessly highest volcanic activity in the Solar system – Io – is one of the
numerous satellites of Jupiter, the innermost of the four Galilean satellites. The study of this
satellite can give very important information about all volcanoes and probably help us in
developing of methods for predicting of terrestrial volcanic eruptions too. Io was discovered in
1610 by Galileo Galilei but the name Io, proposed by the German astronomer Simon Marius in 17th
century, comes into use as late as in the middle of the last century. Prior to it the designation
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Jupiter I was used. The radius of Io is approximately 1821.6 km which makes it comparable with
the Moon’s radius (1738.1 km). It is located at 421 000 km away of Jupiter. This distance is also
very close to the distance between Moon and Earth (384 000 km). But Jupiter is a giant planet with
an enormous mass that attracts Io with a much more powerful gravitational force. That is why the
orbital period of the satellite is as short as 42.5 hours. If the satellite moved slower it would fall on
Jupiter.
As we know, our satellite – the Moon – is the reason for the rise of tidal waves in the
Earth’s seas and oceans. It is less known that the Moon causes tidal waves, although much weaker,
in the Earth’s crust too, and also that the Earth causes tides in the lunar crust. The amazing
volcanic activity, which Io is famous of, is due to the tidal waves caused by Jupiter. Because of the
large mass of Jupiter the tidal forces with which it acts on Io, are huge. The deformations of the
satellite’s shape are of the order of 100 meters. They make it an ellipsoid. The deformations lead to
a release of thermal energy that maintains the satellite’s internal layers heated to high temperatures
for billions of years. If this factor didn’t exist the small sized object would have cooled long time
ago and would have lost its tectonic activity. Now Io’s volcanoes eject sulfur and sulfur dioxide to
heights of hundreds of kilometers above the surface.
A volcano is a geological formation in which rising of magma on the surface of the space
object is observed. In contrast to Jupiter’s satellite Io, on which volcanoes are a result of planet’s
tidal action, the cause of the volcanoes on Earth is different – they are always located close to the
boundaries between the continental plates or in the so called “hot points”. Basic reason for the Io’s
interior to be kept melted for billions of years is the energy released as a result of the tidal friction.
The tidal friction is connected with the motion of the tidal waves with respect to the surface of the
space body and leads to transformation of kinetic energy of the body’s rotation into thermal
energy. In contrast to it the matter under the Earth’s crust is heated by the radioactive decay of
some isotopes contained in our planet. It is the effect of tidal forces that causes many of the
satellites of the great planets in the Solar system to obtain a synchronic rotation – they are always
turned to their planets by one and the same side – their axial rotation has been slowed down until,
in the ideal case, the relative motion of the tidal waves with respect to the surface has stopped.
Such is the situation with our Moon, with the four Galilean satellites of Jupiter, including Io, with
Saturn’s moon Titan, etc. Nevertheless on Io the tidal waves perform a slight periodic motion to
east and west. Due to the elliptical shape of its orbit the satellite is not always turned exactly with
one and the same side to Jupiter and consequently the tidal waves are not fixed with respect to the
satellite’s surface. So the tidal friction keeps acting. Another source of thermal energy is the
changing of the height of the tidal waves depending on whether Io is close to maximal or minimal
distance from Jupiter when it moves on its elliptical orbit.
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During eruptions of Io’s volcanoes the lava reaches heights of more than 370 km, streaming
with initial velocities of hundreds of meters per second and sometimes even up to 1000 m/s.
Terrestrial volcanoes cannot compare to them neither in scale nor in grandiosity – they eject matter
to heights of only around 5 km despite that the initial velocities are not much lower. This is due to
two reasons – the higher acceleration of the gravity force on Earth’s surface and the dense
atmosphere.
Io’s surface is young and ever changing, devoid of meteorite craters because they are erased
by the volcanic activity. It consists mainly of sulfur and its chemical compositions which is the
reason for the color diversity of the satellite. The first photographs of Io taken by Voyager I
spacecraft in 1979, leave the impression that Io’s volcanic lava consists preliminarily of sulfur and
sulfuric compositions, but later scientists reach to the conclusion that it contains sulfur as well as
melted silicate rock rich of sodium. The temperature of the satellite’s surface varies between
–183°C and +1727°C.
We can compare terrestrial volcanic activity also with the geysers of Enceladus – one of the
Saturn’s satellites. It is supposed that from its geysers ice particles are thrown in contrast to Earth
geysers from which hot water is released. According to theory below the surface of Enceladus
there is liquid water. Since Enceladus is about 1000 times less massive than Io, the gravitational
acceleration on its surface is also much lower. Lower is the escape velocity too. For these reasons
the erupted material from its geysers reaches much larger heights [1].
Aim of the project
The aim of our project is to explore Io’s volcanoes and compare them with volcanoes on
Earth and geysers on Enceladus. This means to determine the heights of the ejected plumes and the
initial velocities of the particles and compare them for the corresponding space objects. We will
also search for a relationship between the height of the ejected material and the diameter of the area
within which it is spread on the surface of the object. We will compare that ratio with the
theoretical value obtained by us. We will search for a resemblance between the parameters of Io’s
volcanoes and terrestrial ones. Finally we will propose ideas for future investigation of Io’s
volcanic activity aimed at obtaining valuable information about volcanism in common, which
could be used also for studying and predicting the activity of the Earth’s volcanoes.
Methods of exploration
1.Finding of the height of the jets
To find the real height of the jet thrown away by a certain volcano, we have to use a
photograph of Io, on which the eruption is captured. It is necessary the plume to be seen on the
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limb or very close to the limb of the satellite. We measure the diameter of Io on the image in
millimeters and use it as a scale. Then we measure the height of the jet.
Then, knowing the actual diameter of Io in
kilometers, by means of a proportion we can
find the real height of the jet in kilometers:
h H
 ,
d D
where h is the height of the eruption on the
picture, H is the actual one, d is Io’s diameter
on the picture, D is the actual diameter. So we
find the actual height:
H h
D
d
Fig.1. Measuring the height of the jet h and the
diameter of scattering of the material b during a
volcanic eruption on Io.
2. Finding the initial velocity of the jet
Here we will show how we calculate the initial velocity with which the particles of volcanic
matter are launched by the volcanoes. Let’s imagine how a particle moves if we consider it a
material point. We will imagine the trajectory of a particle moving vertically up, i.e. perpendicular
to the Io’s surface. Since in the time of its flight the particle moves up and all the time the
gravitational force that acts on it is directed down, we can assume that the particle moves with a
constant negative acceleration. Here we must note that actually the particle’s acceleration changes
because of the increasing of the distance to Io’s center from it. To some extend we can compensate
for this effect if we calculate the gravitational acceleration of the particle in the middle of its flight
up to the maximal height, i.e. the acceleration at a height equal to the half of the whole height.
When we study the volcanoes on Earth we take the gravitational acceleration on Earth’s surface –
9.8 m/s for constant. We have the right to do so because the maximal height, to which the particles
are elevated, is too small compared to the radius of the planet. Then we can write down the
formulae for the velocity and the distance for motion with constant acceleration.
We have the following relations:
G  mg
Mm
H
( R  )2
2
4
G 
(1)
(2)
v  v0  gt
H  v0t 
gt 2
2
(3)
(4)
where G is the gravity force acting on the particle, γ is the gravity constant, R is Io’s radius, m is
the mass of the particle, M is Io’s mass, g is the gravitational acceleration on Io at a height equal to
half of the maximal height of the eruption, v is the final velocity of the particle at the maximal
height (it is equal to zero), v0 is the initial velocity of the particle (which we want to find) and t is
the time of the flight of the particle from the ejection to the maximal height. From equations (1)
and (2) we get a formula for the gravitational acceleration on Io:
g 
M
H
( R  )2
2
From equations (3) and (4) we get an equation for the initial velocity of the particle
expressed by the acceleration and the maximal height:
v0  2 gH
So, knowing the acceleration and the height, we can obtain the initial velocity we were
searching for. Probably the particles ejected by a certain volcano don’t have equal initial velocities.
Using the method we describe here, we estimate actually the maximal initial velocity of the
particles, because the outlines of the volcanic “fountain” are determined by the particles reaching
to the maximal height, i.e. by the fastest particles.
3. Comparison of the height and the diameter of the area of spreading of the
volcanic material
On the image (Fig.1) we measure the diameter b of the area within which the matter is
scattered, and as far as we already know the height, we can write the following proportion:
b h
 ,
B H
where b is the diameter of the area on the image and B is the real diameter in kilometers. So we get
the ratio Q 
B
.
H
And now we will find theoretically what has to be the value of Q if we suppose that all
particles are launched with equal velocities but in all possible directions. Farthest away from the
volcano caldera would reach the particles with initial velocities that are at an angle of 45° to the
horizon. Let us consider the trajectory of one such particle in a coordinate system with zero point
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coinciding with the point from where the particle is launched, a horizontal axis X and a vertical
axis Y.
Fig.2. Trajectory of a body thrown at an angle of 45 to the horizon.
We can represent the velocity of the particle by its projections on the axis X and Y – vx
and v y . We have to note that these components are equal because the angle is 45°. Let us now
express these components by the value of v0 . The angle between the vectors v x and v 0 is 45°, as
well as the one between v 0 and v y . According to the Pythagoras theorem applied to the triangle
ABC: vx2+vy2=v02, but as we already mentioned,
vx  v y 
vx=vy. So it follows that 2vх2= v02 or
v0 2
. From here we find v0  vx 2  v y 2 . The changing of the X-coordinate of the
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particle doesn’t depend on the way its Y-coordinate changes with time. Along the vertical axis the
particle moves with a constant acceleration while along the horizontal axis its motion is uniform –
with a constant velocity. This is described by the following equations:
H   v yt 
S  vx t
gt 2
2
on Y axis
on Х axis
where H’ is the maximal height reached by the particle when it is thrown not vertically but at an
angle of 45° to the horizon. From these formulae we get for the distance travelled by the particle:
S  2H
where H is the height reached by a particle that is thrown vertically. But since the distance S is
only half of the diameter of the spreading of the particles, the ratio Q 
(B=2S=4H).
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B
would be equal to 4:1
H
Measurements and results
Explored were 7 volcanoes on Io.
Picture 1
Diameter
of Io
mm
d=147
Diameter
of Io
km
D=3643,2
Height
of eruption
mm
h=15
Height
of eruption
km
H=372
Initial velocity
v0  1050 m/s
Height
of eruption
mm
h=8
Height
of eruption
km
H=126
Initial velocity
v0  650 m/s
Acceleration
at half height
m/s2
g=1,480
Ratio
diameter
to height
Q=2,78
Acceleration
at half height
m/s2
g=1,678
Ratio
diameter
to height
Q=1,12
Tvashtar [9]
Image 2
Diameter
of Io
mm
d=230
Diameter
of Io
km
D=3643,2
[7]
Image 3
Volcano at left
Diameter
of Io
mm
d=148
Diameter
of Io
km
D=3643,2
Height
of eruption
mm
h=4
Height
of eruption
km
H=98
Acceleration
at half height
m/s2
g=1,704
Initial velocity
v0  580 m/s
Ratio
diameter
to height
Q=1,00
Volcano at right
[5]
Diameter
of Io
mm
d=148
Diameter
of Io
km
D=3643,2
Height
of eruption
mm
h=3
Height
of eruption
km
H=74
Acceleration
at half height
m/s2
g=1,726
Initial velocity
v0  505 m/s
Ratio
diameter
to height
Q=2,63
Image 4
Diameter
of Io
mm
d=252
Pillan Patera [4]
Diameter
of Io
km
D=3643,2
Height
of eruption
mm
h=9
Height
of eruption
km
H=130
Initial velocity
v0  661 m/s
7
Acceleration
at half height
m/s2
g=1,68
Ratio
diameter
to height
Q= 2,78
mage 5
Diameter
of Io
mm
d=238
Diameter
of Io
km
D=3643,2
Height
of eruption
mm
h=5
Height
of eruption
km
H=76,5
Initial velocity
v0  513 m/s
Height
of eruption
mm
h=6
Height
of eruption
km
H=65,8
Acceleration
at half height
m/s2
g=1,72
Ratio
diameter
to height
Q=3,03
[8]
Image 6
Diameter
of Io
mm
d=332
Diameter
of Io
km
D=3643,2
Initial velocity
Acceleration
at half height
m/s2
g=1,73
Ratio
diameter
to height
Q= 1,85
v0  478 m/s
Loki [6]
…and 2 terrestrial volcanoes:.
Image 7
Height
of the volcano
mm
Height
of the volcano
km
Height
of the jet
mm
Height
of the jet
km
hв=20
Hв=3,323
h=35
H=5,815
Initial velocity
Etna [2]
v0  338 м/с
Image 8
Height
of the volcano
mm
Height
of the volcano
km
Height
of the jet
mm
Height
of the jet
km
hв=70
Hв=2,3
h=50
H=1,64
Santa Maria [1]
Initial velocity
v0  180 м/с
For our measurements of course, we used much larger printed copies of these images. Here
we have increased their brightness and contrast from which their artistic quality has suffered but the
volcanoes have become more prominent.
To determine the height of the erupted matter of the Earth’s volcanoes we obviously could
not use the diameter of Earth as a scale. Instead, we measured the height of the volcano itself as a
8
mountain peak and we used data for this height in kilometers taken from various sources, and we
tried to find information about the height above the level of surrounding plane and not above the sea
level. As can be seen we have obtained an unrealistically great height of the eruption of Etna volcano
which cannot be relied on. It is probably due to a not true height of the volcano above the
surrounding plane. But scientific data based on the distance travelled by the ejected particles, show
that the initial velocities can reach values of 600 m/s [1]. In fact the values of the initial velocities for
the Earth’s volcanoes obtained by us, are underestimated. It is because we have no way to take into
account the influence of the dense Earth atmosphere on the heights of the erupted matter. Also, for
the Earth’s volcanoes we cannot measure the diameter of the scattering of the material and so we
were not able to calculate the value of Q ratio.
Finally we present our results in Table 1:
Volcano
Tvashtar (Io)
Unknown (Io)
Unknown (Io)
Unknown (Io)
Pillan Patera (Io)
Unknown (Io)
Loki (Io)
Etna (Earth)
Santa Maria (Earth)
Height of the jets
km
Initial velocity
m/s
372
126
98
74
130
76
66
?
2
1050
650
580
505
661
513
478
up to 600
180
Ratio of diameter of
spreading to height
Q
2,78
1,12
1,00
2,63
2,78
3,03
1,85
The first conclusion we can make, is that the initial velocities of the erupted matter by the
terrestrial volcanoes are comparable with the initial velocities if Io’s volcanoes. This makes us
believe that based on exploration of Io’s volcanoes we can get information that could be useful for
studying of the volcanic activity on Earth.
The results we get for the Q ratio differ from the theoretical value of 4:1. All the
experimental values are smaller than it.
The reason is because the theoretical deduction of the parameter’s value is not precise.
During the particle’s flight the direction of the gravity force exerted by Io is changing (Fig.3). Io is
quite small and the eruption heights are quite large so this effect is significant. It makes the particle
describe not a part of parabola but a part of an ellipse and shortens the distance travelled by it. We
suppose that if this factor is taken into account a different maximal limit for Q can be defined.
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V0
парабола
хоризонт
вулкан
елипса
Йо
Fig.3. Trajectory of a particle ejected by a volcano in the Io’s gravity field.
On Fig.4 we present our attempt to seek for a relationship between the value of Q and the
height of the volcanic eruptions. Although our statistic of only seven volcanoes is quite small we
see that for four volcanoes with very different heights of eruption the ratio Q is very similar and
close to 2.7-2.8. Eruptions with greater value of this ratio are not present in the group of volcanoes
explored by us and the values for the four volcanoes are concentrated close to this limit.
Another thing can influence the results – the fact that some volcanoes may eject their
plumes like a narrower fountain, i.e. more matter may be concentrated in jets directed more
vertically and a there could be a lack of matter ejected at smaller angles to the horizon. This could
be valid for the rest of three volcanoes for which the ratio Q of the diameter of spreading of the
material to the height is significantly smaller.
We have to note that we measured the diameter of spreading of the material b not on the
surface of Io but on a line that is tangent to the point of ejection (Fig. 1). The theoretical value for
Q was obtained by us for the case of falling of the material on flat horizontal surface. But the scale
of eruptions of Io’s volcanoes is such that we have to take into account its round shape. That is
why we “cut off” the jets along the line tangent to the satellite’s surface.
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Зависимост между отношението диаметър-височина (Q) и
височината на струите при вулканите на Йо
400
350
300
H, km
250
200
150
100
50
0
0
0,5
1
1,5
2
2,5
3
3,5
Q
Fig.4. Relationship between the Q ratio and the height of eruption of Io’s volcanoes.
It would be interesting for us to create a diagram like the one on Fig.4 but for much greater
number of volcanoes.
It is important also to consider that the eruptions we studied are close but not exactly on the
limb of the satellite’s image. It means that the lowest part of the volcanic plumes could be hidden
below the horizon or projected in front of the satellite’s image. Also, we could see the maximal
height of an eruption in a projection at some small angle. But both these factors would lead only to
overestimating of the Q ratio measured by us, and the values we get are lower than the theoretical
one.
Saturn’s satellite Enceladus
Fig.5a. Ice geysers on Enceladdus [1]
Fig.5b. Ejected matter from the ice geysers – an image with
artificially increased contrast and arbitrary colors [10]
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As can be seen on the pictures – Fig.5a,b – the jets of ice particles ejected by the geysers of
Enceladus, reach to significant heights comparable or may be even exceeding the size of the satellite
itself. It is known that when thrown vertically with an initial velocity equal to the circular velocity
for a certain space body, the height reached by the material should be equal to the radius of the body.
Apparently the particles launched by Enceladus reach and exceed this velocity value. Using data for
the mass M and the radius R of Enceladus, we calculate the circular velocity and the escape velocity
for this satellite. They are as follows:
V1 =
V2 =
M
R
2M
R
 169 m/s
 239 m/s.
Unfortunately we cannot make precise measurements and cannot give numerical values for the
heights because the jets are quite diffuse and their outlines are unclear. But the initial velocities of
the ejected particles are obviously comparable with the circular and the escape velocities and their
values show that they are of one and the same order with that of Io’s and Earth’s volcanoes.
Rings around Io’s volcanoes.
Fig.6b. Pele volcano of Io with a huge red ring of ejected
matter [11]
Fig.6a. Volcanoes on Io with rings around them [10]
The pictures on Fig.6a,b show that around a great deal of Io’s volcanoes there are rings of
ejected material. Especially in the case of Pele volcano (Fig.6b) we notice that the ejected matter is
concentrated in a ring-like formation which makes us conclude that the ejected particles had
similar initial velocities. The outermost part or the ring is formed by the particles that were ejected
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at an angle close to around 45°, if this is the angle at which the maximal distance is reached.
Probably if taking into account the curvature of Io’s surface this angle would be a bit different but
the important thing is that there should be a certain limiting angle. Another reason for the
formation of rings is that the points where the particles thrown at different angles fall on the
surface are more concentrated close to the maximal distance.
Fig.7. Theoretical trajectories of bodies thrown with equal initial velocities but at different angles to the horizon [12]
Fig.7 shows how the trajectory of a body changes when the angle to the horizon changes by
every 5°. We can see that there are correspondences between the distance travelled when the bodies
are thrown at different angles to the horizon. For instance a body thrown at an angle of 10° reaches
to the same distance like a body that is thrown at an angle of 80° and so on. It is seen also that when
the body is thrown at angles of 35° to 55° there is a smaller distance between the points where they
fall. This distance increases with the receding of the value of the angle from 45° at both sides – prior
and after it. Looking at the graph we reach to the conclusion that changing of travelled distance is
not proportional to the change of the angle. For instance if for particles thrown at an angle between
20° and 25° there is a distance of 10 km between the points where they fall, for particles thrown at
angles between 25° and 30° there will be a distance between the points of falling equal to 5 km and
for particles thrown at angles between 15° and 20° the distance would be 15 km. So a concentration
of fallen material is formed close to the maximal distance – if the initial velocities of the particles are
equal. This is the way we could explain the existence of rings and not evenly filled circles of ejected
matter around Io’s volcanoes. So, knowing the diameter of a ring around a volcano we could
estimate the initial velocity of its eruption.
The diversity of rings with various sizes proves that volcanoes on Io erupt differently – with
different power and different initial velocities of the material. The concentration of the material in
clear rings itself is an evidence that the initial velocities of the particles ejected during one eruption
are quite similar. It would be interesting to create a statistical distribution of the rings by diameters
and the initial velocities of the eruptions.
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Conclusion
By measuring the heights of the jets of ejected matter we can estimate the initial velocities of
the particles erupted by the volcanoes. We suppose that from these velocities we can judge about the
physical conditions at a great depth and obtain valuable scientific information about space objects
with volcanoes and geysers.
Our explorations show that although the activity of Io’s volcanoes, terrestrial volcanoes and
even the ice geysers of Enceladus takes place at very different conditions and is caused by very
different reasons, the initial velocities of ejected matter are of one and the same order of value. It
means that the mechanisms of the eruption can be compared and probably the exploration of the
volcanic activity of one space object can lead to common conclusions about the volcanoes also of
another object.
The fact that the scattered material around Io’s volcanoes is concentrated in rings, shows that
during one eruption the initial velocities of the particles ejected at different directions are close to
each other. Hence, the sizes of these rings can also give estimates for the initial velocities of the
eruptions even when the eruptions were not observed directly.
The Jupiter’s satellite Io has more than 100 volcanoes on its surface, of which in every
moment at least several are erupting. If this satellite is studied in details in a short time a lot of
information could be collected about the volcanic activity. Using this information, methods for
predicting of the eruptions could be developed that could probably be applied for the Earth’s
volcanoes too.
Our ideas for future space explorations
So far the volcanoes on Io have been photographed for short time intervals only by the
interplanetary stations Voyager 1 and Galileo – sent by NASA, and New Horizons of ESA. There is
a project of NASA to send a new spacecraft, Io Volcano Observer, in 2015, but it will be in orbit
around Jupiter and will make only a few close approaches to Io. The conclusions we made led us to
the idea of proposing a project for an extended exploration of Io’s volcanoes by means of space
probes. The project will include the following tasks:
1. Continuous observation and photographing of the satellite’s surface in visible and infrared
light. As we know, in orbit around the Sun together with the Earth there are two automatic
probes called STEREO. From their photographs the scientists can obtain stereo images of the
solar prominences. If on one and the same orbit around Io two space probes are launched and
if they fly at an appropriate distance from each other from their photographs stereo images of
volcanoes could be obtained and the heights of the eruptions could be calculated. Cameras
for infrared light would allow volcanoes to be monitored during the night of Io too.
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2. Investigating whether before the eruption of a certain volcano its infrared emission changes
and how does it change.
3. Continuous observation of given volcanoes for finding out whether there is some periodicity
of their eruptions.
4. Collecting of statistical data that would allow us to understand is there a relationship between
the frequency of volcanic eruptions and the distance from Io to Jupiter, i.e. is there a different
frequency of the eruptions when Io is closest to Jupiter and farthest along its elliptical orbit.
5. Comparing of the volcanoes and their eruptions on the side of Io that is turned to Jupiter and
on the opposite side of the satellite.
6. Finding out whether the other great Galilean satellites of Jupiter have an influence on the
volcanoes of Io when they are close to it on their orbits.
7. The astronauts who were on the Moon have installed there special mirrors – laser reflectors.
By sending a laser beam from the Earth and measuring the time for returning of the reflected
signal back to the Earth the scientists have followed the seismic activity of our satellite. By
means of a laser location the seismic activity of Io could be also monitored and we could find
out if it is related with the volcanic eruptions. For this purpose however mirrors have to be
delivered on its surface.
Realization of this project will encounter a lot of problems. The two probes have to fly at an
appropriate distance from Io. It should not be too large because otherwise the powerful gravity of
Jupiter will disturb strongly their motion in orbit around Io. But they should not be too close to the
satellite because they will not have enough broad horizons for seeing the satellite’s surface. The
greatest problem will be radiation. Io is located into the radiation belts of Jupiter where a lot of
particles of the solar wind are concentrated. They move with high velocities because they are
accelerated by the strong magnetic field of Jupiter. It is known that it would be extremely difficult
for Earth astronauts to ever dare to approach as close to the giant planet, because without a
protection they will die from the radiation. The high energetic particles would damage also the
electronic devices of the space probes we propose. The probes must be equipped by a special
protection or they should be cheap enough and will be replaced with new ones from time to time.
For not being very expensive, we propose the probes to have onboard only not very powerful radio
emitters and sources of energy. The information they will collect will be transmitted to a larger
spacecraft that will be on a farther safe orbit around Jupiter. It will have a more powerful energy
source and radio emitter and will send the stored information to our planet. Onboard of this large
station there will be a number of spare probes. When the probes orbiting Io are damaged by radiation
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they will be replaced by others from the main space station and will travel to Io using ion rocket
engines.
Our project will lead in a short time to collecting of great amount of statistical data about Io’s
volcanoes which erupt more often than the Earth’s volcanoes. When the scientists analyze this
information they may discover methods for predicting of the eruptions of the volcanoes on our
planet and preventing of great disasters for the people.
Our team
The leader of the group is Mrs. Eva Bojurova from Astronomical observatory and
planetarium Nicholas Copernicus in the city of Varna, Bulgaria. She has a long lasting experience of
work with students and was the most valuable “wickipedia” that we used for the project. We, the
students. are Yulia Yancheva and Pavel Popov – both of 9th grade. As early as when we were 4th
grade students we started attending the astronomy courses led in Varna observatory and astronomy
continues to amaze us. Working on this project we learned a lot about Io’s volcanoes.
.
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Measuring of the volcanic plumes
Processing of data
Acknowledgements.
We are thankful to Mr. Zahary Donchev from the Institute of Astronomy in the Bulgarian
Academy of Science and to Mrs. Ivanka Tecova from Varna observatory for the valuable advices
they gave us during our work and for their support.
References
1. Wikipedia, http://www.wikipedia.org/
2. BBC, http://www.bbc.co.uk/
3. Visions of Space, http://visionsofspace.com
4. Astrobioloblog, http://astrobioloblog.wordpress.com
5. ILTWMT, http://iliketowastemytime.com
6. Alexis’ page, http://alexis.m2osw.com
7. PDS: The Planetary Data System, http://pds.jpl.nasa.gov
8. National Aeronautics and Space Administration, http://nssdc.gsfc.nasa.gov/
9. Space Spin, http://spacespin.org/
10. NASA, http://www.nasa.gov
11. Biblioteca Pleyades, http://www.bibliotecapleyades.net/
12. Science Blogs, http://scienceblogs.com
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