Butterflies in Space

Butterflies in Space
Research Project
11th D class
Coordinating teacher: Ioana Stoica
“Tudor Vianu” National High School of Computer Science,
Bucharest, Romania
Introduction
Microgravity is a mystery we all wish to unravel – and this can only be done with
experiments and careful observations.
The goal of this research project is to study the behavior of monarch butterflies
(Vanessa Cardui) in a laboratory environment, at constant pressure and
temperature, and to compare the results with the data offered by NASA regarding
the life of butterflies in microgravity. As an aside, in the end we came up with a
term of endearment for our butterflies, naming them Vianuessa Cardui, because
the name of our school is Tudor Vianu.
The essay is structured in several parts. First, in order to choose our research
questions, we studied the effects gravity has on living organisms and of those
considered the aspects we were able to monitor by photos and videos. Then, we
made some suppositions on how butterflies would behave under the effect of
microgravity and how would the lack of gravitational force affect their biological
processes. Also, we compared the actual experimental data collected by us with
the data offered by NASA and verified our suppositions. Finally, we stated the
conclusions of our research and suggested several enhancements and future
studies.
How would the world look without gravity?
The effects of gravity on living creatures, based on scientific studies,
and their consequences in microgravity:
1. Cell size
- Gravity: The size of single biological cells is inversely proportional to
the strength of the gravitational field exerted on the cell. That is, in
stronger gravitational fields the size of cells decreases, and in weaker
gravitational fields the size of cells increases. Gravity is thus a limiting
factor in the growth of individual cells [1].
- Microgravity: This suggests that organisms in microgravity might
develop larger cells and thus, have larger size.
2. Inner/outer skeleton
- Gravity: Organisms evolving on Earth must develop inner or outer
skeletons for not being crushed by the gravitational force [2].
- Microgravity: Bone cells (or exoskeleton cells in case of insects) die
if they can’t attach themselves to something. Without gravity exerting a
downward pull on these bone cells, they float aimlessly about and
eventually perish.
3. Blood circulation
- Gravity: The vascular system must work against gravity in order for
the blood to reach the parts of the body that are higher than the pump
(the heart).
- Microgravity: It’s possible that the lower parts of the body would
receive less blood, while the upper ones will receive more, making
some actions harder to perform and others easier. For example, a
butterfly’s wings may be better vascularized in microgravity since they
are situated in the upper part of the body [3].
What can we measure and observe through
photographs and videos?
Photographs
Videos
-
body shape and structure
the size
colors
life cycle
-
flight patterns
vitality (how active the butterflies are)
Research Questions and Hypotheses
1. Do the butterflies go through the metamorphosis stages
normally?
Hypothesis: Gravity influences a lot of functions in the living
organisms and its absence can have an effect over a larva’s growing
process. Therefore the caterpillar might transform slower into a pupa,
while it could also spend more time in the pupa form. The butterfly
might need more time to fully inflate its wings (because of the effect of
microgravity on its blood circulation) and to dry them.
Methods: We will watch the photos taken by the camera on the ISS
and measure the time needed for the larvae to turn into pupa and for
the pupa to turn into butterfly and see if it takes more or less time.
2. Does microgravity affect their movement pattern?
Hypothesis: Microgravity might influence the butterflies’ speed (they
can achieve greater speeds with far less effort) and cause muscle
atrophy. We presume they will have issues maintaining their balance,
will be disorientated and move erratically. Also, they might become
lazier.
Methods: We will analyze the videos from the ISS and try to find a
pattern for the butterfly’s flight and if such a pattern exists, we will
compare it to the movement patterns seen on Earth.
3. Do they have differences in structure or appearance?
Hypothesis: The larvae on the ISS might be larger than those on
Earth because their cells could be larger in microgravity. The
exoskeleton in all stages of metamorphosis (caterpillar, pupa and
butterfly) might also be slightly thinner because the cells forming this
type of tissue develop much slower in microgravity. Also, the butterflies’
wings might remain a little wrinkled because the low gravity affects the
blood flow that is pumped for inflating them.
Methods: We will measure the size of the butterflies and larvae in the
box on the ISS (from pictures) and compare them to the size of our
insects. The “butterflynauts” may well be larger, but also smaller in size.
Experimental data
I. Measurements
1. Methods applied:
-
we took pictures of our butterflies everyday at 11 a.m. and
compared them with the images from the ISS;
-
we made sketches of the butterflies to compare their physical
features;
-
we monitored the pressure and temperature levels using the
same barometer and thermometer each day, to make sure there
were no fluctuations;
-
we measured the size of the larvae and butterflies, using a ruler;
-
we used mathematical equations to interpret the obtained data.
2. Sketches
Butterflies on Earth
Butterflies on the ISS
3.
a)
Day
11
(16.03.2010)
12
(17.03.2010)
13
(18.03.2010)
14
(19.03.2010)
15
(20.03.2010)
16
(21.03.2010)
Data tables:
On Earth:
Size Temperature Pressure
(cm)
(C)
(mbarr)
3.8
4
4.4
4.4
4.4
4.4
22
23
23
23
23
23
Observations
1017
First day of
measurements. Due to
unfavorable weather
conditions, we only have
4 larvae, instead of 5.
1017
The larvae get used with
the new environment and
start to build a wire
network.
1017
The network becomes
more complex; the food
level decreases.
1017
The necessary amount of
food has been consumed;
the larvae become
inactive.
1017
The larvae used the
network to attach to the
lid; they gradually come
into the “J” position.
1017
The larvae are being
moved to a bigger
habitat.
Photo
b)
On the ISS:
Day
Size
(cm)
Temperature
(C)
Pressure
(mbarr)
10
(18.11.2009)
1.7
25
1013,25
11
(19.11.2009)
2.2
25
1013,25
12
(20.11.2009)
2.8
25
1013,25
13
(22.11.2009)
3.3
25
1013,25
14
(23.11.2009)
3.5
25
1013,25
15
3.6
25
1013,25
(24.11.2009)
Photo
4. Data processing
a) Habitat conditions
We registered only minor fluctuations of pressure and temperature in our
research laboratory. Moreover, the measured values were in the accepted limits,
similar to those on the ISS. Thus, these conditions shouldn’t have a significant
influence on the butterflies’ behavior and development.
b) Butterfly size:
The graph in Figure 1 illustrates a comparison between the sizes of the larvae on
Earth and those on the ISS.
We noticed that caterpillars on the ISS are smaller than ours, but they keep
growing in length for all 6 days, while the ones we measured in the laboratory
stopped growing in length after the first 3 days of measuring.
5,00
4,50
4,00
3,50
3,00
Earth
2,50
ISS
2,00
1,50
1,00
0,50
0,00
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Figure 1: Representation of daily sizes for the larvae on Earth and on the ISS
c) Growth rate:
We calculated the growth rate of the caterpillars as the arithmetic mean of the
slopes of the lines forming the graph:
-
Growth rate for our research butterflies: (0.2+0.4+0+0+0)/6 = 0.12;
-
Growth rate for the butterflies on ISS: (0.5+0.6+0.5+0.2+0.1) = 0.38.
Notice the value is greater for the “butterflynauts”.
d) Life cycle:
Vianuessa
Cardui
Butterflynauts
(research butterflies)
Caterpillar
Chrysalis
13 days
11 days
Vanessa
Cardui
(general information)
6-7 days
7-8 days
7-11 days
7-11 days
Notice the butterflies in space evolve faster than the ones raised in our
laboratory. [9]
II. Observations
a) On the ISS:
We analyzed the available footage which captured the butterflies’ behavior. The
moments recorded were from two consecutive days:
December 3, 2009: there is only one butterfly emerged from the
pupa;
-
December 4, 2009: a second butterfly emerges from the pupa.
Here are our observations below:
12/03/09:
-
the butterfly is floating aimlessly inside the box;
------------------it does some short, sudden moves trying to control its direction, but
doesn’t seem to have a target; it’s moving its body rather than its wings;
12/04/09:
-
the elder butterfly (1 day old) is moving very slowly;
the newly-emerged butterfly looks disorientated and is desperately
trying to stretch its wings;
-------------------
the butterflies have problems maintaining their balance;
they are trying to attach themselves to the walls (not flying
aimlessly anymore);
there are some flying attempts, but they can’t control their speed
and they keep hitting the walls;
while one of the butterflies is more active (uses its wings often and
tries to fly), the other one is static and moves using mainly its limbs.
b) On Earth:
On Earth, Vanessa Cardui butterflies fly in a smooth, balanced way with a
constant beat stroke of about 20 Hz assuring enough lift for a straight,
horizontal flight. The monarch butterflies are capable of flying many miles
in their lengthy migrations over North America and some of them even
cross parts of the Atlantic. The length of these journeys exceeds the
normal lifespan of most monarchs and only the fourth generation of
butterflies completes them [4],[5],[6].
III. Error sources
While analyzing and interpreting our data, we must also consider possible
error sources:
• Imperfections of the instruments used (rulers, thermometers
etc.);
• Gradients of temperature and pressure in our laboratory;
• Disturbance of the butterflies’ activities by human presence
(although we tried not to influence them in any way);
• Approximation of the results;
• Small number of studied butterflies.
Conclusions
Considering the small number of Painted Lady butterflies studied in our
laboratory, a generalization would be somewhat inappropriate. We tried,
wherever possible, to compare our data with general characteristics for the
Vanessa Cardui species and, unfortunately, we noticed several differences.
However, some conclusions can still be inferred.
We’ve noted our observations below, for each of the proposed research
questions:
1. Do the butterflies go through the metamorphosis stages
normally?
The butterflies on the ISS seem to evolve slightly faster than the ones on
Earth. Also, while in their caterpillar stage, they continue to grow for the
entire period, while our research butterflies stagnate to a constant value
after the third day.
2. Does microgravity affect their movement pattern?
Monarchs on the ISS exhibit fairly modest flying attempts. Immediately
after emerging from the pupa and drying their wings, the Vanessa Cardui
butterflies try to use their wings for movement. The videos recorded on the
ISS show that initially they are disoriented and cannot control their speed
properly. However, they shortly adapt their behavior to the environment
and omit using their wings extensively. Also, after periods of merely
floating in microgravity, the butterflies seem to attempt to control their
direction with sudden twists of the abdomen.
On the other hand, the butterflies in our laboratory seemed disoriented
immediately after emerging, but this was only a temporary state, as they
soon started enhancing their flying skills. Also, Earth-raised butterflies
seemed to be more active than the ISS-raised ones.
In general, Vanessa Cardui butterflies on Earth fly in a balanced manner, a
sign that they evolved on the planet from generation to generation. They
migrate over large distances in different periods of the year, flying
hundreds of miles in a controlled manner, which the butterflies on the ISS
would certainly not be capable of [7],[8].
3. Do they have differences in structure or appearance?
Our initial hypothesis was that the butterflies living in microgravity would be
larger than the ones on Earth. This proved to be wrong. On the contrary,
the “butterflynauts” are smaller in size than our butterflies – the caterpillars
differ with over 1 cm in length. We believe that butterflies born and raised
in microgravity might grow to be larger because their cells would expand
constantly and there wouldn’t be any accommodation period.
However, the wingspan of the butterflynauts is approximately 5.5 cm,
slightly larger than the average values for Vanessa Cardui. [4]
Also, another difference we observed is that the wings of the
“butterflynauts“ remain slightly wrinkled, probably due to the effect of
microgravity.
Questions and Proposals for Further Study
- How would butterflies born on the ISS behave on Earth? Would they
survive?
- Would butterflies born on the ISS, in microgravity conditions, grow
bigger than the current “butterflynauts”?
- Have any changes been observed in the behavior of the butterflies
after returning from the ISS? If so, are the effects similar to those
experienced by human astronauts? (e.g. dizziness etc)
- Would a larger box (and perhaps fitted with a cleaning system to
eliminate the frass and food residue) allow a better study of the flight
patterns? Perhaps a larger box would let the butterflies actually fly, not
just float in microgravity?
Acknowledgements
Our sincere gratitude goes to everyone at NASA and BioEd for giving us
the chance to take part in such an amazing project and to feel, even if only
for a short while, like true scientists.
Also, many thanks are due to Tim and Margaret Jenkins, at Gribblybugs,
for sending us the caterpillars all the way from Coventry, England, despite
the harsh weather conditions. [10]
Bibliography and Resources
[1]. http://en.wikipedia.org/wiki/Gravitational_biology
[2]. http://library.thinkquest.org/C003763/print.php?page=human03
[3]. http://astrobiology.nasa.gov/ask-an-astrobiologist/question/?id=761
[4]. Opler, P. A., and Wright, A. B., 1999. Peterson field guide to western
butterflies. Houghton Mifflin Co., Boston. 544 pp.
[5]. http://monarchwatch.smugmug.com/Monarchs-in-Space/Monarchs-onEarth/10367121_hyZuM#735342687_AiVnt
[6]. http://monarchwatch.smugmug.com/Monarchs-in-Space/Monarchs-on-theSpace-Station/10305636_wwEsm#735343086_WAPzr
[7]. http://en.wikipedia.org/wiki/Monarch_%28butterfly%29
[8]. http://www.monarch-butterfly.com/
[9]. http://www.monarchbutterflyusa.com/Cycle.htm
[10].
www.gribblybugs.com
Photooos!
Our stars, the Vianuessa Cardui!
Us!
Verifying the
laboratory conditions
(the flowers insure
increased humidity)
Recording the
data
Measuring the
butterflies’ sizes
A group photo – 11D class and Mrs. Ioana Stoica