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Dark Nebulae
Dark nebulae are nonluminous nebulae that are observable since it obscures light from other sources. Nebulae are diffuse clouds of interstellar dust and gas. The shape, size, and characteristics of nebulae may vary significantly because some are the remains of dead stars and others are star nurseries. Dark nebulae are found in areas with no nearby stars. These clouds do not emit or reflect enough light for them to be visible. In fact, the view from the stars behind them is usually blotted out by the dust particles. This paper will exclusively explore on dark nebulae.
Normally, these clouds range from 1-10 AU and are less dense than the deepest vacuum in the laboratories of the Earth. They are also thick such that they obscure light from the stars behind them. However, the size of these clouds can be from a few light years up to 600 light years. Additionally, the total mass of dark nebulae can reach several million masses of solar. These clouds can appear to be big depending on the number of stars in it. If there are many stars, the clouds will appear huge, but it can appear small if there are a few stars in it.
These clouds existed from a long time ago. Claudius Ptolemaeus did the first record of stars that appeared to be nebulous around 150 AD. Since then, many astronomers have continued discovering these clouds until an American astronomer Beverly Turner Lynds compiled and published a survey of dark nebulas in the year 1960. However, it is true to say that dark nebulae existed a long time ago even before the manufacture of the first instrument or device that could observe and discover the clouds. Traditionally people used to view these clouds as a bright patch in the milk way even without noticing what they were.
Dark nebulae are different from other nebulae because they emit no light and contain high concentrations of interstellar dust. This high concentration of dust helps the bodies of dark nebulae to obscure the light from sources behind them. Another characteristic of these clouds is that they contain molecules and elements in the form of gas and liquid. Besides, these molecules and elements are thought to be excellent raw materials for the formation of new objects such as stars in space. These clouds also have a characteristic of a hole in them.
Scientists have discovered that these clouds contain common elements like helium and hydrogen. The clouds also contain some simple elements such as methanol, ammonia, water, and carbon dioxide. The combination of these molecules can form grains, which play a significant role in the formation of the star. They also have an unusual chemistry that consists of frozen nitrogen, formaldehyde, ethyl alcohol, and other complex organic molecules. These clouds contain an average temperature that ranges from about 10-100 Kelvin, which allows hydrogen molecules to form leading to the formation of stars.
Sometimes, it can be difficult to observe these clouds because they do not emit their light. However, due to the light source of stars behind them, dark nebulae can be observed very easily with eyes since the dust particles in them obscure the view from the source of stars. These clouds also among the most challenging objects that can be observed through the eyepiece of a telescope. As a result, these opaque dust and gas clouds can be viewed well by shadowing stars that are more distant and glowing gas clouds. However, the observation of these clouds can be precise when using large binoculars even though the majority of the dark nebulae will be small.
According to astronomical time scale, these clouds do not last long. The hot young stars burn off the dust and gas that remained after a few million years, leaving a small loose cluster of stars associated with gravity. Mostly, these clouds can only be observed in a short while for the moment the stars have disappeared the dark nebula also vanishes. However, it can be hard to determine what time the stars will go. These clouds are usually visible at night when the stars are glowing in the sky, but after the night is over the clouds may also disappear.
Dark nebulae cannot support life for living organisms because it does not emit light, which is very crucial for the growth of plants that animals depend on mostly. Besides, the elements contained in these clouds cannot support life for most of them are known to be excellent raw materials used for the formation of stars. There is also a high concentration of dust and gas, which is not ideal for the survival of living organisms. These clouds are known to vanish after a while when the stars disappear. However, there is not a living organism that can survive in an environment that is expected to go at any time.
Stars inside dark nebulae make them glow with beautiful blues, greens, and reds. These stars make a dark nebula have beautiful aspects, which most people will enjoy watching them. These clouds also create a beautiful shell of diffuse gas that makes it look nice when observing. Another fascinating aspect of these clouds is the field of view of the stars that are behind them. Viewing these stars behind these clouds creates a beautiful field of view. There is also a view of nearby objects such as globular clusters that contributes to the beautiful appearance of these clouds.
Dark nebulae are formed when the view of the stars is blocked by dark, smoky clouds of gas and dust. The substances prevent the light from the stars, leading to the formation of these clouds. In spite of the blocking of these stars, the dark nebulae and the stars are closely linked. These clouds contain huge amounts of cool cosmic dust, which is a nursery where new stars are being born. However, if it were not due to the cluster of stars, the dark nebulae could never be in an observer position because they do not create and emit their light.
In conclusion, the size of these clouds depends on the number stars that are behind them, and they existed from a long time ago. In fact, their existence is unpredictable since the first astronomer did the first record around 150 AD. Dark nebulae have different characteristics from other nebulae due to their high concentration of dust and gas. Besides, their composition of elements plays a significant role in the formation of stars. However, it is true to say that these clouds do not last long and cannot support life. They also have beautiful aspects due to the stars inside that make them glow in different colors.