It has been centuries now since humankind looked up to the sky and wondered, is there any other life out there apart from our own? Ever since that question has been asked, it's been a mystery and many scientists and astronomers have come out with many theories about what lies out there and what they look like, if any exist. However, these theories will remain only as theories before someone can actually find evidence of what lies out there. Evidence that the scientists found might prove that humans are not alone in this universe or it also might not be true. Humans have created fiction of other life forms to fill out our curiosity of the unknown to us.
Many scientists and astronomers are trying to find evidence of other living creatures and things out there in the universe. For example, NASA has discovered that there might be life on the fourth planet from the sun, Mars. According to NASA administrator Daniel S. Goldin issued a statement saying, "NASA has made a startling discovery." He called the evidence "exciting, even compelling, but not conclusive...I want every to understand that we are not talking about 'little green men.' These are extremely small, single-cell creatures that somewhat resemble bacteria on Earth. There is no evidence or suggestion that any higher life form ever existed on Mars." Many NASA's scientists do back up their statements with evidence although other scientists do not agree with NASA's announcement about life on Mars. Ever since NASA has discovered living things on Mars, Mars has been the center of attention in the world of science.
Even before the discovery of extremely small, single-cell creatures that somewhat resemble bacteria on Earth, a group of scientists found a meteorite approximately "the size of a large Idaho's potato" on the Antarctica ice field (Jaroff 60). The meteorite originated from Mars before it came to the Earth's surface thousands of years ago. This was determined when scientists compared the composite of the meteorite with what Viking 1 and Viking 2 had collected. These probes were the first two probes that landed on Mars and analyzed the sample of the Mars soil and atmosphere. After this discovery was made, NASA scientists started to make several tests using a lot of sophisticated equipment. NASA scientists were very excited when they heard this meteorite came from Mars. What makes this finding even more interesting is that scientists found out that these remains consists of a group if carbonate globules. These carbonate globules are "a mineral that crystallizes in the presence of watera key ingredient for life" (Naeye 49).
Bacteria on Earth also produce the same carbonate substances and that is why they were excited about it. Accompanying the carbonate was the substance called polycyclic aromatic hydrocarbons (PAHs), which bacteria and other living things commonly produced. These substances (PAHs) are made up of hydrogen and carbon. Nevertheless, not all scientists agreed with this finding, because they said that the PAHs substance could occur in almost anywhere without having anything to do with life. For example, it could occur in a car exhaust or in a chicken on the grill (Shreeve 40).
A group of scientists from New Mexico also conducted an experiment of their own on the same meteorite that NASA used but their results were different of those from NASA. They found no evidence or trace of life form in the particular rock (Fleck). They said that they did not find anything to suggest that there was life on Mars. According to Jim Papike " 'It [the result of our research' doesn't mean that they're wrong' UNM researcher Jim Papike said of the NASA claim that the meteorite contains evidence of the possibility of life on Mars. 'But our dad gives no support for that' " (Fleck).
Scientists also have theories about how life might have evolved on Mars billion of years ago. From the pictures and evidence that the probes collected, scientists said that there was no way for life to flourish on the surface of Mars today, but maybe there was life there billion of years ago. This is because the surface of Mars is contaminated with lethal carbon dioxide ice and surviving there is impossible for anything. Still, there is hope for life to exist there today, under the surface. Scientists' theories said that after the water on the surface dried up, there was still water forming from underground and maybe this was enough for life to flourish there. Two probes called Mariner 6 and Mariner 7 were orbiting the planet when they witnessed what were similar to clouds on Earth. These clouds were formed when the carbon dioxide condensed from the surface. If there are clouds, there could surely be water no matter how much it is.
Scientists also found many canals that suggested that there was some amount of water on the surface before it dried up billions of years ago. They suggested that these canals were formed by the river that once flowed there. There are scientists who are uneasy with this theory. They go against it by saying that the canals were formed by natural causes by soil erosion, win condition and others also believe that it was only an optical illusion. When the Galileo orbiter reached Ganymede, one of Jupiter's moons, the orbiter also found minimum evidence that supports scientists' theories about life there. The orbiter found that the atmosphere there might have what it takes to harbor life. The surface, the moons experiences some thunderstorms almost like what the Earth has on its desert. The Galileo orbiter also made a flyby at the second Jupiter's moon, Europa. At this moon, the orbiter managed to get an image of an icy surface that scientists said might have an underground ocean. This speculation was based on what we have here on earth. In 1974, a group of glaciologists found that there is a vast ocean or lake underneath the Antarctica polar ice cap that has been there for more than two million years. Another planet that scientists thought that could support life is the moon of Saturn, Titan. They found that this moon is the only moon that has an atmosphere even thicker than what we have here on Earth and it is full of organic substances. But all this speculation about Titan will remain, until a probe known as Huygens-Cassini reaches the moon and sorts through the speculation.
After being presented by all the available evidence, scientists and astronomers still do not know for sure whether there is other life out there in the universe. The finding of the microbes in the meteorites also did not help scientists answer the questions about other life form. As for now, scientists will base most of their research on theories that fellow scientists made regarding other life out there. Hopefully someday these theories might help give us the answer to the oldest question in the world of astronomy, 'are we alone in this universe?'.
- Fleck, John. "Similar UNM Meteorite Study Found No Evidence of Mars Life." Albuquerque Journal 8 August 1996.
- Jaroff, Leon. "Life on Mars." Time Aug. 19, 1996: 58 - 64.
- Naeye, Robert. "Was There Life on Mars?" Astronomy Nov. 11, 1996: 46 - 53.
- Shreeve, James. "Find of the Century?" Discover Jan. 1997: 40 - 41.