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S. Masiero and M. S. Erculiani
extinct or extant life on other planetary bodies. Plant-life absorbs visible light, using
photosynthesis to convert that light into energy. Visible light is more likely to bounce
around within the leaf to give it the best chance of absorbing the useful wavelengths,
whereas infrared light is more likely to be reflected and transmitted. (More green
light is reflected than other visible wavelengths, but the variation is no more than a
few percent.) Leaves are comprised of water-filled cells surrounded by air and the
structure of the cell causes some light to be internally scattered, which either exits the
leaf as transmitted light below the leaf, or reflected light above the leaf. The reflected
infrared light creates a sharp peak in the spectrum known as the vegetation red edge.
It is still not fully understood why plants reflect infrared light, but some studies suggest that it is to avoid damage by overheating. It is possible that the detection of the
vegetation red edge on other planets would serve as evidence of life.
9.3 The ExobioLaboratory
The ExoBioLaboratory will be developed at the Planetarium of GAL Hassin
Foundation—International Center for Astronomical Sciences at Isnello, Sicily (Italy).
The Planetarium setting lends itself well as an imaginary planetary environment
thanks to the possibility of exploiting the colored lights of the Planetarium and the
space available to recreate–with plants and other effects—a hypothetical exoplanetary environment. Another space available at the GAL Hassin Center can be the
Solar Laboratory, a dark windowless room where it is possible to build a science
laboratory. The ExoBioLab is targeted to Italian students of Secondary School First
Grade (aged 11–14) and Secondary School Second Grade (aged 15–16).
The basic idea is to realize 4 different environments for 4 different kinds of
exoplanets, according to the 4 different types of stars: F, G, K and M stars. On Earth
the processes that led to the birth of life took about one billion years. For this reason,
the search for extrasolar planets—and even more the search for life—is directed
towards rocky planets (or Super-Earths) orbiting around four main spectral types of
stars: F, G, K and M. The spectral type is directly related to the lifetime of a main
sequence star and, consequently, to the possibility of formation of long-lived and
stable planets adequately suited to develop life.
For the ExoBioLab, 4 different stars mean 4 different kinds of bulbs for lights
inside the Planetarium:
F star (temperature about 6000–7500 K): a white bulb;
G star (temperature about 5200–6000 K): a white-jellow bulb;
K star (temperature about 3700–5200 K): an orange bulb;
M star (temperature about 2300–3700 K): a red bulb.
The Sun has a specific distribution of colors of light, emitting more of some colors
than others. Gases in Earth’s air also filter sunlight, absorbing different colors. As a
result, more red light particles reach Earth’s surface than blue or green light particles,
so plants use red light for photosynthesis. There is plenty of light for land plants, so
S. Masiero and M. S. Erculiani
extinct or extant life on other planetary bodies. Plant-life absorbs visible light, using
photosynthesis to convert that light into energy. Visible light is more likely to bounce
around within the leaf to give it the best chance of absorbing the useful wavelengths,
whereas infrared light is more likely to be reflected and transmitted. (More green
light is reflected than other visible wavelengths, but the variation is no more than a
few percent.) Leaves are comprised of water-filled cells surrounded by air and the
structure of the cell causes some light to be internally scattered, which either exits the
leaf as transmitted light below the leaf, or reflected light above the leaf. The reflected
infrared light creates a sharp peak in the spectrum known as the vegetation red edge.
It is still not fully understood why plants reflect infrared light, but some studies suggest that it is to avoid damage by overheating. It is possible that the detection of the
vegetation red edge on other planets would serve as evidence of life.
9.3 The ExobioLaboratory
The ExoBioLaboratory will be developed at the Planetarium of GAL Hassin
Foundation—International Center for Astronomical Sciences at Isnello, Sicily (Italy).
The Planetarium setting lends itself well as an imaginary planetary environment
thanks to the possibility of exploiting the colored lights of the Planetarium and the
space available to recreate–with plants and other effects—a hypothetical exoplanetary environment. Another space available at the GAL Hassin Center can be the
Solar Laboratory, a dark windowless room where it is possible to build a science
laboratory. The ExoBioLab is targeted to Italian students of Secondary School First
Grade (aged 11–14) and Secondary School Second Grade (aged 15–16).
The basic idea is to realize 4 different environments for 4 different kinds of
exoplanets, according to the 4 different types of stars: F, G, K and M stars. On Earth
the processes that led to the birth of life took about one billion years. For this reason,
the search for extrasolar planets—and even more the search for life—is directed
towards rocky planets (or Super-Earths) orbiting around four main spectral types of
stars: F, G, K and M. The spectral type is directly related to the lifetime of a main
sequence star and, consequently, to the possibility of formation of long-lived and
stable planets adequately suited to develop life.
For the ExoBioLab, 4 different stars mean 4 different kinds of bulbs for lights
inside the Planetarium:
F star (temperature about 6000–7500 K): a white bulb;
G star (temperature about 5200–6000 K): a white-jellow bulb;
K star (temperature about 3700–5200 K): an orange bulb;
M star (temperature about 2300–3700 K): a red bulb.
The Sun has a specific distribution of colors of light, emitting more of some colors
than others. Gases in Earth’s air also filter sunlight, absorbing different colors. As a
result, more red light particles reach Earth’s surface than blue or green light particles,
so plants use red light for photosynthesis. There is plenty of light for land plants, so