Astronomy Search for Life in the Solar System
- Definition of astrobiology.
- Recent discoveries related to the search for life in the solar system.
- Mercury and Venus
- Mercury is not suitable for organic life because of its closeness to the sun that makes it very hot and dry.
- Venus surface is very hot due to extremely intensive greenhouse effect.
- The Earth and Venus resemble each other in size but Venus’ stratosphere lacks water vapor, since it comprises 96.5% of the carbon dioxide.
- The atmospheric pressure on Venus’ surface is 90 times more than on the Earth’s surface.
- Mars comprise an intricate artificial system of canals, which is a proof of intellectual life on Mars capable of accomplishing great infrastructural projects.
- The polar ice caps on Mars contain a considerable amount of fresh water, which could sustain the forms of organic life.
- The different colors of Mars are a result of its episodic powder storms covering wide areas.
- Saturn’s Moons
- Saturn has no less than 62 moons with different sizes.
- Titan is the largest moon in the solar system with a substantial atmosphere made up primarily of nitrogen and little amounts of methane.
- Titan’s surface is extremely cold, about 180°C, and is covered with lakes and oceans of liquid methane.
- Lightning has not been detected in the moon’s troposphere, and the amino acids and other multifaceted molecules might have developed with time.
- Rhea, the second largest Saturn’s moon, has an extremely thin carbon dioxide and oxygen atmosphere.
- Enceladus is white in color and reflects virtually 100% of the sunlight.
- The need to establish and equip the next generation of astrobiology researchers and educators.
- World institutions establish their own programs aimed at advanced astrobiology studies.
Astrobiology refers to the study of life in the cosmos (Catling 1). From the time when early humans started looking at the skyward and imagined the stars and the moon as distant campfires, humanity began questioning if there were other living creatures in the Universe. For instance, the ancient Greeks thought that the Earth was not the only planet that could support life. However, they lacked the required technology to substantiate such assumptions. During the late 20th century, the new findings of the conceivable remains of microbial life in a Martian meteorite, as well as discovery of the first planets rotating around other stars, triggered the interest of the scientists regarding the presence of life beyond the Earth. In the 21st century, the innovative field of astrobiology connected the required scientific ability that offered answers to these questions that were subject of human curiosity since ancient times. This paper provides the information regarding the recent discoveries related to the search for life in our solar system, bringing together numerous fields, such as astronomy, biology, chemistry, geology and atmospheric sciences among others.
Mercury and Venus
Based on thorough research, scientists concluded that Mercury was not suitable for the development of organic life due to its closeness to the Sun, which made it exceedingly hot and dry, and did not allow formation of the atmosphere. Similarly, despite that numerous researchers of the 20th century supposed that there was a possibility of intelligent life on Venus, the detailed analysis of the planet’s conditions showed that its surface was very hot due to extremely intensive greenhouse effect. The Earth and Venus resemble each other in size, regardless of Venus being only 28% closer to the Sun as compared to the Earth. However, unlike the Earth, Venus’ stratosphere lacks water vapor, since it comprises 96.5% of the carbon dioxide. Its atmosphere is approximately 100 times as immense as the Earth’s atmosphere, implying that atmospheric pressure on Venus’ surface is 90 times more than on the Earth’s surface (Schulze-Makuch 4).
The surface of Venus has a regular temperature of 460°C because of carbon dioxide atmosphere, which is a greenhouse gas. This means that the temperatures are high enough to melt metals like lead, tin and zinc. For instance, when the Soviet spacecraft landed on Venus, the heat and pressure did not allow them to remain in operation for more than few hours. Some scientists consider a possibility that Venus could have some amount of surface water on the earlier stages of its formation, but it evaporated due to the hot temperatures.
For many centuries, scientists have been interested in finding out whether there was life on Mars. For instance, in 1877, the famous Italian astrophysicist, Giovanni Schiaparelli, observed the planet through his telescope and saw surface formations that resembled channels (Washam 2). Furthermore, Percival Lowell, the American astronomer, supposed that the channels of Mars comprised an intricate artificial system of canals, which, in his opinion, provided proof that there was intellectual life on Mars capable of accomplishing great infrastructural projects (Washam 2).
Other astrophysicists found out that the polar ice caps on Mars contained a considerable amount of fresh water, which could sustain the forms of organic life. Moreover, observations have shown that the color of the planet in some regions close to the polar caps changed in different seasons, which could be a trace of some form of the plant life. However, it is now evident that the different colors are a result of the planets’ episodic powder storms covering wide areas (Schulze-Makuch 204). Many unmanned missions, such as Mariners 4, 6, 7 and 9, Spirit, Opportunity and Phoenix, reached the Mars’ surface to search for life. Despite numerous attempts to find its traces, the scientists still has found no solid evidence to confirm this theory.
According to astronomers’ observations, Saturn has no less than 62 moons (Nola). The moons vary in sizes, which can range from a diameter of one kilometer to that of the major moon in the solar system, Titan, which is bigger than the planet Mercury. Numerous moons have topographies and other features that make them useful to astrobiologists. However, Titan is the only moon in the solar system with a substantial atmosphere. The atmosphere of Titan is almost 1.5 times the atmospheric pressure of the Earth, and it is made up primarily of nitrogen and little amounts of methane. Titan’s surface is extremely cold, about 180°C, and is covered with lakes and oceans of liquid methane. It is also important to note that methane can exist both as a solid liquid and as a gas on Titan (Nola). This can make its role similar to the role of water on the Earth in the climate change. Currently, lightning has not been detected in the moon’s troposphere, and the amino acids and other multifaceted molecules might have developed with time.
Rhea, the second largest Saturn’s moon, has an extremely thin carbon dioxide and oxygen atmosphere. However, it comprises only a trillionth of the density of the Earth’s atmosphere. In addition, Enceladus, another moon of Saturn, also comprises surprising characteristics that could be interesting for astrobiologists. It is white in color and reflects virtually 100% of the sunlight. It also has fountains on its surface that sprout out jets of water mixed with ammonia and carbon-based compounds. The temperatures around these geysers are high, whereas the other part of the moon is very cold, with a temperature of 220°C below zero.
As the field of astrobiology is continually growing, there is a need to establish and equip the next generation of astrobiology researchers and educators, since there are many other discoveries to be made that could help in understanding origins of life in the universe. Some world institutions establish their own programs aimed at advanced astrobiology studies. For instance, the University of Washington has established its own Astrobiology Program (UWAB) devoted to studying the current astrobiology issues and preparing the future astrobiologists. The study of astrobiology will certainly not end until the time when humanity will ascertain about the possibilities of existence of life in the entire universe.
Catling, David C. Astrobiology: a very short introduction. Vol. 370. Oxford University Press, 2013.Print.
Nola, Redd. “Saturn’s Moons: Facts about the Ringed Planet’s Satellites.”, Space.com, 2016. Web. 8 July 2016.
Schulze-Makuch, Dirk, and Louis N. Irwin. Life in the Universe: Expectations and Constraints. Berlin: Springer, 2008. Print.
Washam, Erik, “Lunar Bat-Men, the Planet Vulcan and Martian Canals” Smithsonian magazine, December 2010. Web. 8 July 2016