Could there be life on the Gas Giants Moons

        I have talked about the phases of the moon as well as observing the night sky and then I have talked about life on Earth and what makes it possible. I now want to discuss the possibility of life arising in other parts of the solar system. Mars has always been thought to be the place that life would be found but not in the distant past moons around the gas giants have been places of interest in the debate of where life might exist. The ones that I am going to briefly discuss today are Jupiter’s moons (Callistro, Ganymede, and Europa) I will also look at two of Saturn’s moons (Titan and Enceladus). The first four moons that were mentioned are thought to have liquid oceans under the crusts of ices. One knows that there should not be water around Jupiter because it is too cold for liquid water. This means that there have to be a way to explain this liquid. Ganymede and Europa are thought to be heated by tidal forces. Callistro is not heated by tidal forces but it is thought to be caused by radioactivity in its center.  As mentioned above the four moons that have liquid water are thought to be a good place to start to look for life.  Every life-form that we know of needs water, these ranges from the largest mammals to the smallest microbes. Water plays major roles in metabolism as well. One of the places that one should look if they start to search for life on these moons would be under the layer of ice. One may want to start to look at the interface between the rocks and the water; there may be deep sea vents. This is one of the possibilities for the formation of life on Earth. Titan is not like the other moons it is the only moon that has a very dense atmosphere. It has a nitrogen atmosphere and has methane clouds; it is known to have geological activities, lakes, rivers, and seas.  It would not be liquid water bodies but would be seas of hydrocarbons. This environment is very similar to the ones found in the tar ponds in Trinidad and Tobago. There are extremophiles that live in there lakes therefore it may be possible for life to be on Titan. The one major problem of the analog (lake) and Titan is the temperature. Titan is a lot colder and that may cause a problem. Even though life has not been found in the solar system yet scientis are interested in possibility of life on the gas giants large satellites.

Earth’s Magnetic Field

        We are not the only planet or body in our solar system that has a magnetic field but it is a property of our planet that protects the Earth and allows life to prosper. We have a magnetic field because we have a large iron core and the convection of the molten on the outer core.  This is what causes an electric current and this leads to the magnetic field. The magnetic field produces the magnetosphere that in turn protects us. An image of the magnetosphere is shown in the picture below.

Figure obtained by: http://www.wired.com/wiredscience/2010/03/earths-magnetic-field-is-35-billion-years-old/

        The sun gives planets the energy the need to undergo photosynthesis; it gives us the heat needed for liquid water. The sun is able to give us many things that are important to life however, the sun is not all good. The solar wind and solar flares can be dangerous to life. The solar wind is when the sun is continually releasing these charge particles. Solar flares are when the Sun spews out large amounts of these charged particles. The Earth’s magnetosphere channels the solar wind around the planet so that it does not reach the surface. If the magnetosphere was absent then the solar wind and flares would strip away the atmosphere. This means that these charge particles would impact the surface and may make it sterile. We would also be exposed to solar radiation that is very harmful to life. UV radiation breaks carbon carbon bonds. When one thinks about life on earth, all of it is carbon based as we know and therefore it would destroy life. There are other consequences of not having an atmosphere. For example there would be very drastic changes in temperature from day to night. All of these factors are important to life and we are here in part because our magnetosphere protects us.  Recently there has be large sunspots that have been found on the Sun. This increased the activity and released more solar particles. Because of this increase in activity more particles are being trapped at the poles causing Aurora. 

Earth and Its Moon

                        There are over ninety moons in our solar systems but our moon is special because of its size. There are moons that are larger than ours but they are around gas giants or Jovian planets. Most of the moons in the solar system are captured bodies such as meteoroids and asteroids.  This means that the planet had enough gravity to capture the bodies and to keep them in orbit. The moon is so much larger than Phobos and Deimos which are Mars’s moons. This means that Earth’s moon could not have been captured like the rest. There have been many explanations for this but one has won out over the rest. The explanation for the formation of our moon comes from a large impact. When the early Earth was formed it was impacted by a Mars sized body, this impact made the Earth’s surface molten and it let off ejecta that started to orbit the Earth. These ejecta then collided together to form our present day moon. This formation was unique and also gave Earth some of its unique characteristic. The impact has been hypothesized to have increased the speed of rotation of the Earth, as well as the tilt of the Earth these two characteristics give Earth its day and night lengths as well as its seasons. The moon also stabilizes the moon. Without this stabilization Earth would be a tumbling Earth. This means that the Earth would flip and there would be more volcanic eruptions and tsunamis. It is also thought that the impact gave Earth it large iron core as well as its large size.   This iron core gave it its magnetic field which also allows Earth to have life.  I will talk about the magnetic field next time and its significance.

Back to Star Gazing

        There are many constellations that one can find in the night sky however this week I am going to try to find some of the Zodiac Constellations that can be seen in the night sky this time of year. In popular culture there are twelve zodiac signs but in the night sky there are thirteen. I was successful in locating Pisces and Aquarius which are two of the zodiac constellations. Doing some research I found that the best way in which to locate these two constellations that are beside each other is to locate the “Great Square of Pegasus”. Once I have located this then I found the Pisces is right below the Great Square. Once Pisces is located the head of the fish on the right is right beside Aquarius.  Another useful body that Stellarium showed that would be bright in the sky is Jupiter. Jupiter will be located below and a little to the right of Pisces. I also know that in order to locate these constellations I have to look southeast. With all of this information that I found I was able to locate these two constellations.

Figure Obtained from Stellarium

        Above is a map of the night sky one can see that I can find the two constellations if I locate the great square. I was successful in finding the two constellations. Zodiac Constellations are unique; these constellations are the ones that the sun passes through in the sky. This means that presently the constellation Virgo is in the sky during the day and that is where the sun resided. This concept can be explained by looking at the figure below.

Figure obtained from: http://www.2012dayafter.com

         This shows that sun moves through different zodiac constellation different times in Earth’s orbit and thus different times of the year. At this time of year we see Aquarius and Pieces and the sun passes through Virgo. The zodiac constellations can change and you may not have the same sign as you think you have.