![]() Some chemical compounds detected in comets are listed below. In recent years there have been multiple missions to comets (and some to asteroids) by robotic spacecraft to get samples of the materials coming from a comet. The ices in a comet are easily driven away and vaporized into space, unless trapped inside the object. As a comet gets near the Sun, it will form a tail. The ice in a comet is not only water ice but can include frozen organic compounds. What Chemicals are in Comets?Ĭomets are made up of water ice, dust, and some rock. So do a number of other molecules in the cell. ![]() In a real living cell, the organic compounds are often much larger molecules and they are much more complex. But, proteins can be made up of a sequence of several hundred or more amino acids. Amino acids are relatively small organic molecules with generally around 3 to 11 carbon atoms. The terms “right-handed” and “left-handed” has to do with the order and three-dimensional arrangement of the atoms in the molecule. Sugars are also needed by living things and living cells require only the right-handed sugars. This property of “handedness” is referred to with the technical terms “chirality” or “stereoisomerism,” and a few other terms. The atoms in an organic molecule work the same way. Both of our hands have the same parts, but because of the different arrangement of the parts of our left and right hands, they are mirror images of each other. This “handedness” in organic molecules is very analogous to our hands. Only the left-handed forms of these amino acids can be used in living things. But in living things, out of the many amino acids that are possible, only 22 of them are used to make proteins, and there is another very special requirement. Amino acids make up proteins and enzymes in living cells. There are often multiple forms of many organic compounds. Organic compounds in a living cell have a three-dimensional arrangement that is important to the functions of molecules in the cell. But as scientists learned more about chemistry they learned how to make organic compounds, like those that are in living things, but make them from basic constituents like water, gases in our atmosphere, and other compounds that are considered “inorganic.” Organic compounds are carbon compounds, that usually have four elements in them, including carbon, hydrogen, nitrogen, and oxygen. The term “organic” used to mean substances that only came from living things. Could comets or meteorites help explain the origin of life? So this brings us to the questions about life starting on our planet. The composition of comets and asteroids have been studied by astronomers, and meteorites found on Earth have been studied similarly. So scientists have proposed that at least some of the chemical compounds necessary for life could have come from space. Life as we know it requires organic chemicals. Only after the impacts slowed down and the Earth’s surface cooled off could life have had a chance to get started and survive. These impacts provided the raw materials. In the secular scenario for our planet, Earth began very hot and was bombarded for a long time with objects from space. Many scientists would also take this logic to the next step and say that if life could form on Earth from nonliving chemicals that the same could happen on extrasolar planets orbiting other stars. If life could start, there is a large presumption that biological evolution could proceed from then forward. So without a Creator-God to bring about life on our planet, how would it start? Evolutionary biology theories will not help answer this question, because there cannot be evolution till after life exists! The question is more about how the first simplest life forms could form from chemicals and survive on Earth. Earth is generally thought by most scientists to be about 4.56 billion years old and the origin of life, though debated, is put at more than 3 billion years ago. There are many technical details in the secular theories about the origin of Earth and of life. If you do not accept the Biblical account of the beginning of Earth and how life started on our planet, naturalistic science is turned to by many for answers.
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