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Astronomy

The natural science of the universe

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Horsehead Nebula

Level of difficultyEasy
Reading time6 min
Views243

The whimsical image of a chess knight in profile among the stars is perhaps the most recognizable among deep space objects. It can be said that the Horsehead Nebula tops the recognition rankings among nebulae and galaxies. Perhaps the Andromeda and Orion Nebulae resonate more with the general public, but only specialists and advanced amateurs know what they look like. Even among them, there are often cases when the famous Andromeda Galaxy is confused with another galaxy, even by experienced popularizers of astronomy. The Orion Nebula, too, can look different in pictures taken with various filters. Yet, the profile of the chess knight allows every inhabitant of Earth to recognize that in front of them is the one-of-a-kind and completely unique Horsehead Nebula.

Let's begin by noting that when we talk about the Horsehead Nebula, we refer to two fundamentally different formations in this region of our Galaxy. Only together do they create this memorable visual image. Moreover, what we see—the glowing diffuse background—is not the Horsehead Nebula. It is a dark silhouette against a light background—a bizarrely shaped dust cloud opaque to the visible radiation of stars and nebulae. If there were no relatively bright emission nebula behind it, we might not even know about any dark gas-dust cosmic horse.

The background for the recognizable horse profile is created by the hydrogen nebula IC 434, discovered by William Herschel in the late 18th century. However, Herschel did not notice any amusing details in the outline of this nebula, although he was an excellent observer—much more keen-sighted and attentive than most of his followers. There are also objective reasons for this—telescopes in Herschel's era were imperfect, and their dark metal mirrors lost from 50% to 80% of the light that entered them.

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Rosette Nebula

Level of difficultyEasy
Reading time3 min
Views192

The large but sparsely populated constellation Monoceros, barely visible to the naked eye, can take pride in hosting an extraordinary treasure: the Rosette Nebula. Monoceros is a relatively recent addition to the star map. Lacking bright stars, astronomers of the pre-telescope era deemed this region unworthy of a constellation. After all, how could a constellation exist without luminous stars? A few 4th-magnitude stars hardly suffice to form a recognizable figure. Consequently, old star maps depicted nothing within the Winter Triangle — formed by Betelgeuse, Sirius, and Procyon (between the constellations Orion, Canis Major, and Canis Minor. Only with the telescope’s invention did it become clear that this region contained notable objects, necessitating a name. Johannes Hevelius, creator of a stunning star atlas, coined the name in the early 18th century. Thus, astronomers gradually accepted a mythical, horse-like beast with a sharp horn — located where the third eye might be — among the winter constellations.

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Carina Nebula

Level of difficultyEasy
Reading time3 min
Views278

The term "Carina Nebula" is sometimes translated as "Nebula of Carina," evoking the image of a beautiful female name. However, this is a misinterpretation. "Carina" is Latin for "keel," referring to the keel of a ship—not just any ship, but the Argo, depicted on ancient star maps. Over time, the Argo constellation was divided into several modern constellations: Carina, Puppis, Vela, and Pyxis (Compass). The stars of the Argo are invisible from mid-northern latitudes. Even in the best seasons (winter and spring), Carina, Puppis, and Vela remain below the horizon. They can be observed from the northern tropics and farther south. However, in ancient times, when Greek astronomers imagined the Argo in the sky, the Earth's rotational axis was positioned differently due to precession. This allowed the Argo to be visible from Mediterranean shores. Precession, a gradual shift in the Earth's axis, completes a full cycle every 26,000 years. Over three millennia, the stars of the Argo gradually disappeared from the northern sky.

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Unveiling the Technological Odyssey: Evolution of Weather Forecasting

Level of difficultyEasy
Reading time3 min
Views330

Weather forecasting has come a long way from the days of observing the sky and relying on folklore to predict upcoming conditions. Advancements in technology have revolutionized how we perceive, understand, and forecast weather patterns. From the early barometers to modern satellites and supercomputers, each innovation has significantly enhanced our ability to predict weather accurately. Let's take a journey through the evolution of weather forecasting technology and explore how it has transformed over the years.

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Symphony of Clouds: Interpreting Nature's Weather Signals

Level of difficultyEasy
Reading time3 min
Views289

In the vast expanse of the sky, clouds weave an intricate tapestry that holds invaluable insights into the workings of our atmosphere. Far from being mere adornments adrift on the winds, clouds are dynamic entities that serve as indispensable harbingers of weather patterns. Their varied forms and movements offer a window into the ever-changing conditions of our atmosphere, allowing meteorologists to unravel the mysteries of weather forecasting with increasing precision.

Clouds, in their multitude of shapes and sizes, provide vital clues about atmospheric conditions, from temperature and humidity to air pressure and wind patterns. By understanding the different types of clouds and their characteristics, meteorologists can decipher the language of the skies, predicting everything from clear skies to impending storms.

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Decoding the Science Behind Weather Prediction

Reading time3 min
Views539

Weather, a perennial topic of conversation, influences our daily lives in myriad ways. From planning outdoor activities to safeguarding against natural disasters, understanding weather patterns is crucial. But have you ever wondered how meteorologists predict the weather with such accuracy? Let's delve into the fascinating world of weather prediction and uncover the science behind it.

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The color of the Moon and the Sun from space in terms of RGB and color temperature

Reading time17 min
Views3.6K
It would seem that the question of the color of the Moon and the Sun from space for modern science is so simple that in our century there should be no problem at all with the answer. We are talking about colors when observing precisely from space, since the atmosphere causes a color change due to Rayleigh light scattering. «Surely somewhere in the encyclopedia about this in detail, in numbers it has long been written,» you will say. Well, now try searching the Internet for information about it. Happened? Most likely no. The maximum that you will find is a couple of words about the fact that the Moon has a brownish tint, and the Sun is reddish. But you will not find information about whether these tints are visible to the human eye or not, especially the meanings of colors in RGB or at least color temperatures. But you will find a bunch of photos and videos where the Moon from space is absolutely gray, mostly in photos of the American Apollo program, and where the Sun from space is depicted white and even blue.

Especially my personal opinion is nothing but a consequence of the intervention of politics in science. After all, the colors of the Moon and the Sun from space directly relate to the flights of Americans to the Moon.

I searched through many scientific articles and books in search of information about the color of the Moon and the Sun from space. Fortunately, it turned out that even though they do not have a direct answer to RGB, there is complete information about the spectral density of the solar radiation and the reflectivity of the Moon across the spectrum. This is quite enough to get accurate colors in RGB values. You just need to carefully calculate what, in fact, I did. In this article I will share the results of calculations with you and, of course, I will tell you in detail about the calculations themselves. And you will see the Moon and the Sun from space in real colors!
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Celestia: Bugs' Adventures in Space

Reading time6 min
Views1K
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Celestia is a three-dimensional space simulator. Simulation of the space allows exploring our universe in three dimensions. Celestia is available on Windows, Linux and macOS. The project is very small and PVS-Studio detected few defects in it. Despite this fact, we'd like to pay attention to it, as it's a popular educational project and it will be rather useful to somehow improve it. By the way, this program is used in popular films, series and programs for showing space. This fact, in turns, raises requirements to the code quality.
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