10 Surprising and Intriguing Facts About Our Solar System - Our Sun and Its Family of Planets - You Didn't Know About!
Remember those models of the solar system that you studied? The solar system is even cooler! Here are 10 things you may not know.
- The hottest planet is not closest to the Sun. Many people know that Mercury is the closest planet to the Sun. Therefore, there is nothing mysterious about why people consider Mercury to be the hottest planet. We know that Venus, the second planet from the Sun, is on average 45 million kilometers farther from the Sun than Mercury. The natural assumption is that, being farther away, it must be colder. But the assumptions may be wrong. Mercury has no atmosphere, no insulating "blanket" to help keep the Sun warm. On the other hand, Venus is enveloped in an unexpectedly thick atmosphere that is 100 times thicker than Earth's.
This, in itself, would serve to prevent some of the solar energy from returning back to space and thus raising the overall temperature of the planet. But in addition to the thickness of the atmosphere, it is composed almost entirely of carbon dioxide, a potent greenhouse gas. Carbon dioxide freely transmits solar energy, but is much less transparent to long-wave radiation emitted by a heated surface. The temperature thus rises to levels much higher than expected, making Venus the hottest planet.
In fact, the average temperature on Venus is about 875 degrees Fahrenheit (468.33 Celsius), enough to melt tin and lead. The maximum temperature on Mercury, the planet closest to the Sun, is about 800 degrees Fahrenheit (426.67 Celsius). In addition, the absence of an atmosphere causes the temperature of Mercury's surface to change by hundreds of degrees, while the thick mantle of carbon dioxide keeps the surface temperature of Venus stable, hardly changing at all, anywhere on the planet or at any time of the day or night!
- Pluto is smaller than the US. The longest distance between the borders of the United States is almost 4,700 km (Northern California to Maine). By the best current estimates, Pluto is just over 2,300 km across, less than half the width of the United States. Of course, it's much smaller than any major planet, which is probably why it's a little easier to understand why it was "downgraded" and stripped of planet status a few years ago. Pluto is now referred to as a "dwarf planet"
- "Asteroid fields". In many science fiction films, spacecraft are often endangered by dense asteroid fields. In fact, the only "asteroid field" known to us exists between Mars and Jupiter, and although there are tens of thousands of asteroids (perhaps more) in it, there are huge distances between them, and the probability of asteroid collision is small. In fact, spacecraft must be deliberately and carefully directed towards asteroids in order to have a chance to even photograph them. Given this, it is highly unlikely that spacecraft will ever encounter asteroid swarms or belts in deep space.
- You can create volcanoes using water as magma. Mention volcanoes and everyone immediately thinks of Mount St. Helens, Mount Vesuvius, or perhaps Mauna Loa's lava caldera in Hawaii. Volcanoes require the molten rock to be called lava (or "magma" when it's still underground), right? Not really. A volcano forms when an underground reservoir of hot, liquid mineral or gas erupts onto the surface of a planet or other non-stellar celestial body. The exact composition of the mineral can vary greatly.
On Earth, most volcanoes have lava (or magma) with silicon, iron, magnesium, sodium, and a variety of complex minerals. The volcanoes of the moon Io appear to be composed primarily of sulfur and sulfur dioxide. On Saturn's moon, Neptune's moon Triton, and many others, the driving force is ice, good old frozen H20!
Water expands when it freezes, and tremendous pressure can build up, much like a "normal" volcano on Earth. When the ice breaks to the surface, a "" is formed. Thus, volcanoes can operate both on water and on molten rock. By the way, we have relatively small eruptions of water on Earth called geysers. They are associated with superheated water that comes into contact with a hot reservoir of magma.
- The edge of the solar system is 1000 times further than Pluto. You can still think that the solar system extends to the orbit of the much loved dwarf planet Pluto. Today, astronomers do not even consider Pluto as a full-fledged planet, but the impression remains. However, astronomers have discovered many objects orbiting the Sun that are significantly further away than Pluto.
These are "Trans-Neptunian Objects", or "". The Kuiper Belt, the first of two reservoirs of solar cometary material, is thought to extend 50-60 astronomical units (AU, or Earth's mean distance from the Sun). Even more distant in the solar system, the huge cloud of Oort comets can extend as far as 50,000 AU. from the Sun, or about one and a half light years - more than a thousand times further than Pluto.
- Almost everything on Earth is a rare element. The elemental composition of the planet Earth is iron, oxygen, silicon, magnesium, sulfur, nickel, calcium, sodium and aluminum. Although these elements have been found in places throughout the universe, they are only trace elements that are largely dwarfed by the much higher abundances of hydrogen and helium. Thus, the Earth, for the most part, consists of rare elements. However, this does not mean that the Earth has any special place. The cloud from which the Earth formed had a much higher abundance of hydrogen and helium, but being light gases, they were expelled into space by the heat of the sun when the Earth was formed.
- There are rocks of Mars on Earth. Chemical analysis of meteorites found in Antarctica, the Sahara desert and elsewhere has shown that they originated on Mars. For example, some contain pockets of gas that are chemically identical to the Martian atmosphere. These meteorites may have been blasted away from Mars due to a stronger meteorite or asteroid impact on Mars, or due to a huge volcanic eruption, and then collided with Earth.
- Jupiter has the largest ocean in the solar system. Orbiting in cold space, five times farther from the Sun than Earth, Jupiter retained much higher levels of hydrogen and helium when it formed than our planet. In fact, Jupiter is mostly made up of hydrogen and helium. Given the mass and chemical composition of the planet, physics requires hydrogen to turn into a liquid. In fact, there must be a deep planetary ocean of liquid hydrogen. Computer models show that it is not only the largest ocean known in the solar system, but also about 40,000 km deep - about as deep as the entire Earth!
- Even small space bodies can have moons. It was once thought that only planet-sized objects could have natural satellites or moons. In fact, the existence of moons, or the ability of a planet to gravitationally control a moon in orbit, has sometimes been used as part of the definition of what a planet really is. It just didn't seem reasonable that smaller celestial bodies would have enough gravity to hold the moon. After all, Mercury and Venus don't have them at all, and Mars only has tiny moons. But in 1993, the Galileo probe noticed near the 35 km wide asteroid Ida, its one and a half kilometer moon - Dactyl. Since then, moons have been found orbiting about 200 other minor planets, making it even more difficult to determine the "true" planet.
- We live inside the sun. We usually think of the Sun as a big, hot ball of light 150 million kilometers away. But in fact, the outer atmosphere of the Sun extends far beyond the visible surface. Our planet revolves around this faint atmosphere, and we see evidence of this as gusts of solar wind create the Northern and Southern Lights. In this sense, we definitely live "inside" the sun. But the solar atmosphere doesn't end on Earth. Auroras have been observed on Jupiter, Saturn, Uranus and even on distant Neptune. In fact, the outer solar atmosphere, called the "heliosphere", is supposed to extend at least 100 astronomical units. This is almost 16 billion kilometers. In fact, the atmosphere is probably drop-shaped, due to the movement of the Sun in space, with a “tail” stretching for tens and hundreds of billions of kilometers.
The solar system is cool. These were 10 facts about the solar system that you might not know.
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> Omega Centauri
What does it look like globular cluster Omega Centauri constellation Centaurus: description, characteristics with photo, diameter, how many stars, origin, age, facts.
(NGC 5139) is a globular cluster 15,800 light years distant. It lives on the territory of Centaurus and occupies the first positions in terms of luminosity, size and massiveness in the entire galaxy.
With a diameter of 150 light years, the globular cluster of the constellation Centaurus contains 10 million stars. At least 200 globular clusters can be found in the Milky Way, but Omega Centauri has a different origin. Many believe that it was formed from the remnant of a dwarf galaxy that was destroyed in a collision with ours.
Such clusters move in orbit around the galaxy without entering the disk. They contain tens of thousands and millions of stars, united by gravity. Usually their age is almost the same, but in Omega Centauri diversity reigns: from 12 billion years to very young.
This situation led scientists to suggest that we are not facing a typical globular cluster, but a dwarf galaxy devoid of external stars.
The Omega Centauri Cluster is home to several million Population II stars. Age - 12 billion years. It is believed that stars appeared within 2 billion years with several peaks of activity. The center is so strongly compressed that the gap between the members is 0.1 light year.
In 2008, researchers used data from the Gemini Observatory and the Hubble Telescope to find an intermediate-mass black hole at the cluster's core. The images showed a large stellar concentration moving at high speeds.
It was clear that an object was hiding in the center of the globular cluster, contacting the stars with the help of gravity. It was 40,000 times as massive as the sun. Only a black hole was suitable for such parameters. Later analyzes attempted to challenge the results, but failed to rule out the presence of a hole. But the maximum mass was limited to 12,000 solar.
Omega Centauri can be found without the use of technology, but it is better to take a telescope with you. In a dark sky, it will cover the visible Moon in size. Residents of the northern hemisphere can only observe at a specific time. The favorable period for the review is April-June. You can also watch from January to April, but it is shown before sunrise. If you live south of the equatorial line, then track from March to October.
Use Spica (brightest in Virgo) to search. Together they reach the highest point in the sky in the south. The cluster is 35 degrees south of the star. Be sure to use the online star chart on the site to find Omega Centauri yourself through a telescope.
With a mass of 5 million solar masses, Omega Centauri is 10 times more massive than a typical member of its kind (almost like a galaxy). In terms of massiveness, it is surpassed only by Mayall II (in M31). Also, the cluster has a much higher rotation speed, and the shape is slightly flattened.
Facts about the star cluster Omega Centauri
In 1667, Edmund Halley from Saint Helena discovered the cluster in the constellation Centaurus. He became the first to name it a non-stellar object. He added it to a list of six "luminous spots". Even earlier, Ptolemy correlated with the star.
Johann Bayer used Ptolemy's information. For the first time, the name Omega Centauri was reflected in his Uranometry (1603). The object was not recognized as a globular cluster until 1826. James Dunlop called it "a beautiful ball of compressed stars". As a result, John Herschel used his powerful telescope in the 1830s and finally cemented the modern status.
In 1746, Jean Philippe de Chezo lists it as one of the 21st nebula, and in 1755 Nicolas Louis de Lacaille catalogs it as L I.5.
One of the closest stars to us, Kaptein, is believed to have formed within the cluster. We are talking about a red dwarf, removed by 13 light years (Painter).
Unfortunately, from the middle latitudes of the Northern Hemisphere of the Earth, only part of the constellation Centaurus is visible, and objects in it, due to their low position above the horizon, can be observed with certain inconveniences.
Centaurus - screenshot from the planetarium program
On a long spring night, the constellation Centaurus (sometimes called the Centaur) rises low, low above the southern horizon. For most residents of the Northern Hemisphere, this area of \u200b\u200bthe sky is inaccessible, since the declination of the constellation is from -30 to -64 degrees. At mid-northern latitudes, only half of the constellation Centaurus is visible.
The main stars of the constellation
The brightest star in the constellation is α Cen. This is a star with an apparent total brightness of -0.27m. is a physically multiple star system consisting of three components: α Cen A, α Cen B and , which is usually considered separately.
Proxima Centauri, Hubble image
Components A and B in all their astrophysical parameters are similar to our luminary - the Sun, they are in close classes and similar in size. Moreover, the star α Cen B has . Proxima, on the other hand, is a red dwarf located just 4.24 light years from the Sun.
The brightest luminary visible from middle latitudes is the star ν Cen (Menkent). The star has a brightness of 2.1 magnitudes and can be easily found if the straight line connecting Vindematrix (ε Vir) and (α Vir) is extended to the Southeast.
Deep space objects seen from mid-latitudes
The constellation Centaurus is unusually rich in deep space objects, but only two of all this abundance are available to an observer from the Northern Hemisphere. One of them is the brightest globular cluster NGC 5139, known since ancient times as ω Cen.
History of Omega Centauri
The history of its appearance in the sky as a cluster is replete with many paradoxes. It has long been considered a star, and in the 2nd century AD it was included by Claudius Ptolemy in his Almagest under the name ω Centauri. Abbot Nicola Louis de Laical, who observed it, recorded the cluster in his "Catalogue of non-stellar objects" under the index 1.5. In 1677, Edmund Halley, observing ω Cen, called it a nebula, and only in the first half of the 19th century did John Herschel identify it as a globular cluster.
In order to find NGC 5139, you must first find the stars μ and ζ Cen. From ζ Cen to the West, visually set aside a segment equal to the distance between these stars. In that place, even with the most modest binoculars, a rather bright foggy ball of light can be seen. Although the cluster has a magnitude of 3.7, finding it with the naked eye at mid-latitude is not an easy task. It rises above the horizon no higher than five degrees, and the projection of the cluster onto the celestial sphere can be seriously affected by atmospheric refraction or, even slight, near-horizontal illumination.
Observations of NGC 5139
Journey to NGC 5139
In more powerful binoculars, the cluster shows a certain graininess due to its incomplete resolution to individual luminaries. According to some amateur astronomers, it is possible to completely resolve ω Cen to the stars, provided it is sufficiently high above the horizon, already in a 100 mm telescope. At a latitude of 45 degrees (+-)5, comfortable observations would require an optical instrument with an aperture of more than 5” (125 mm). It is quite interesting to compare Omega Centauri with the Great Globular Cluster in Hercules!
Centaurus A
Galaxies Centaurus A. Photo with a total exposure of 120 hours!
The next target in this constellation is the fifth brightest galaxy in the earth's sky - NGC 5128 or Centaurus A. This is a fairly close to us lenticular S0-type galaxy with a polar rim (belt), which is also the most powerful source of radio and X-ray radiation, in fact case, there is an active galaxy closest to us (not to be confused with AGN).
Virtual journey to the galaxy
Centaurus A is a more accessible object than ω Cen, as it has a declination of -43.1 degrees with an apparent brightness of 6.6 magnitudes. With all these parameters, observations of NGC 5128 in the middle northern latitudes are very difficult. At the 50th parallel, with 10x50 binoculars, you can recognize a vague, almost circular patch of light, five degrees West of μ Cen. It will not be possible to distinguish such a noticeable dust lane (the same polar rim) due to the low location of the object above the horizon.
A Deep Look at Centaurus A
Centaurus A in different ranges of the spectrum
Southern objects of Centauri
In the part of the constellation invisible from the middle latitudes, there are a considerable number of objects of deep space worthy of attention. The vast majority of these are open clusters, such as, for example, NGC 5617, Tr22 and Lynga2, located between Rigel Centaurus and Hadar (α and β Cen). On the territory occupied by the Centaurus, there is another attraction of the Southern sky - the Great Coal Sack. Partly this dark nebula (the largest dust pocket in the Milky Way) is located in the constellation , partly in Centaurus. It is excellently visible to the naked eye.
Briefly about the constellation
constellation history
All globular star clusters are impressive, but Omega Centauri is incredible. Sparkling with 10 million stars, it is the largest "globe" of the Milky Way.
With a mass of 5 million suns, Omega Centauri is 10 times more massive than a typical globular cluster. Omega Centauri has a diameter of 230 light years. It is a starry city sparkling with 10 million stars.
Globular clusters usually have stars of the same age and composition. However, studies of Omega Centauri show that there are different stellar populations in this cluster that form at different time periods. Perhaps Omega Centauri is the remnant of a small galaxy that has merged with the Milky Way.
How to see Omega Centauri. Omega Centauri, the largest and brightest star cluster in the Milky Way, is visible far to the south, in the dome of the sky. It is perfectly visible from 40 degrees north latitude to the south (the latitude of Ankara, Turkey).
From the Southern Hemisphere, Omega Centauri appears to be much higher in the sky and is a great sight to behold. If you are in the Northern Hemisphere and want to see this cluster, be aware that Omega Centauri can only be seen at certain times of the year. It is best seen in the evening sky from the Northern Hemisphere in late April, May and June evenings. Residents of the northern hemisphere can also see Omega Centauri from January to April, but they must be prepared to stay up after midnight or get up before dawn.
Spica, the brightest star in the constellation Virgo, will serve as your guide star in your search for Omega Centauri. When Spica and Omega Centauri move south and reach the highest point in the sky, they do it in unison. However, Omega Centauri lies about 35 degrees south of (or below) the sparkling, blue-and-white Spica. For reference, your fist at arm's length is about 10 degrees in the sky. .
Omega Centauri is a globular, not an open star cluster. The symmetrical, round appearance of Omega Centauri distinguishes it from clusters such as the Pleiades and Hyades, which are open clusters of stars.
An open star cluster is a free collection of tens to hundreds of young stars in the disk of the Milky Way galaxy. Open clusters are weakly held together by gravity and tend to disperse after a few hundred million years. Globular clusters orbit the Milky Way outside the galactic disk. They contain tens of thousands or millions of stars. Closely bound by gravity, globular clusters remain unchanged after 12 billion years. As a rule, open clusters visible to the naked eye are from hundreds to several thousand light-years away. By contrast, globular clusters are typically located tens of thousands of light-years away.
At 16,000-18,000 light-years from Earth, Omega Centauri is one of the few of our galaxy's 200 or so globular clusters that are visible to the naked eye. It looks like a dim, fuzzy star, but the mere presence of Omega Centauri is a testament to its size and majesty. Like any globular cluster, Omega Centauri is best.
In summary, the Omega Centauri globular star cluster is by far the largest known globular star cluster visible from Earth. It is about 10 times larger than a regular globular cluster. It is best seen from Earth's Southern Hemisphere, but we in the Northern Hemisphere can also see it at certain times of the year.
Position of Omega Centauri - right ascension: 13 h 26.8 m; declination: 47 degrees 29′ south.
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Observations by the Hubble Space Telescope and the Gemini Ground Telescope have provided strong indications that a black hole with a mass of about 30,000-50,000 solar masses is located in the star cluster Omega Centauri. This, firstly, confirms that Omega Centauri is not an ordinary globular cluster of our Galaxy, but the remnant of a dwarf galaxy captured by ours. Secondly, the mass of an open black hole fits perfectly into the known dependence of this quantity on the mass of the spherical component in galaxies, allowing this correlation to be extended to the region of small (by galactic standards) masses. Previously, such small masses were not reached.
Omega Centauri (ω Centauri), or NGC 5139, is a giant star cluster with a mass of about 5 million solar masses. It looks like a globular in shape, but a detailed analysis of its properties has long made scientists doubt that we are simply dealing with the largest globular cluster in our Galaxy. It is believed that Omega Centauri is a small galaxy captured by ours about 10 billion years ago and “ripped off”, that is, we see only a dense core, and the outer stellar shells of the dwarf galaxy were destroyed by tidal forces and the stars from them became part of our Galaxy.
This origin is indicated by many properties of Omega Centauri, for example, a diverse stellar composition, which requires several episodes of star formation (stars in globular clusters have approximately the same age and chemical composition, although more recently some diversity of stellar populations has begun to be found in ordinary "globular clusters").
Omega Centauri is not the only cluster for which it is assumed that in the past it was a galaxy in its own right. In addition, we now see the process of absorption of a dwarf galaxy in the constellation Sagittarius (the globular cluster M54 may be the core of this galaxy). Nevertheless, Omega Centauri is the largest of these clusters, and its study is of particular interest.
If this cluster was once a galaxy in its own right, then it is reasonable to suspect that there is a massive black hole at its center, since modern data tell us that every galaxy with a massive bulge (spherical component; from English bulge "bulge, swelling") has a black hole. The more massive the bulge, the more massive the black hole.
The authors of the article conducted a detailed study of the distribution of stellar density in the cluster, as well as the velocities of stars. The fact is that the presence of a large central mass leads to a small peak - a cusp (from English cusp "peak, ledge") - in the distribution of stars, and in addition, a massive object will make the stars rotate faster - that is, the velocity dispersion in the most central region of the cluster will increase (unfortunately, it is difficult to measure the speeds of individual stars in the cluster due to their high spatial density, therefore, determine the dispersion).
On fig. Figure 1 at the beginning of the article shows two density distributions in the cluster. The lower curve corresponds to the distribution of stars - luminous matter (roughly speaking, we counted the number of stars per unit volume and thus estimated the mass). The upper curve reflects the contribution of the dark (invisible) mass component. This curve was obtained from the results of studying the distribution of stellar velocities in the central part of the cluster. After all, the speeds of stars do not depend on whether the substance that attracts them glows or not. The stellar velocity dispersion is determined from the spectrum. Spectral lines that are shifted due to the Doppler effect are investigated. By measuring the velocity dispersion of stars at different distances from the center of the cluster, one can construct a mass distribution profile in it.
The significant difference between the two curves indicates that there is an invisible mass at the center of the cluster. The dark component dominates only in the center, which indicates that its mass is small compared to the total stellar mass of the cluster, and also that the invisible matter is highly concentrated in the central part.
So, from the picture it is clear that something dark "sits" in the central part of the cluster. What could it be? Of course, it could be one massive black hole. But maybe there are some alternatives? For example, it could be a cluster of 10,000 stellar remnants (neutron stars or black holes). An analysis of this possibility using numerical models shows that such a structure could not have formed in Omega Centauri. So we are dealing with a single black hole.
Let me remind you that there are two types of black holes: stellar-mass and supermassive. The former are formed after the collapse of massive stars. Accordingly, the masses of such black holes range from units to several tens of solar masses. The latter are located at the centers of many galaxies (see review). Supermassive black holes gain their mass by accreting gas and dark matter, and by merging with other central black holes when galaxy mergers occur. If the galaxy is massive enough, then a black hole can grow to several billion solar masses. However, there are still many ambiguities in resolving the problem of the growth of the mass of supermassive black holes (see, for example, articles 0705.2269 and astro-ph/0506040). In addition, astrophysicists talk about black holes of intermediate masses. First, this is discussed when discussing the so-called. Second, intermediate-mass black holes are suspected in two globular clusters. In the case of Omega Centauri, we are most likely dealing with a relative of supermassive black holes. That is, the mechanism of formation of a black hole was the same as that of its "relatives" in the centers of galaxies. Such a mechanism should not work for ordinary globular clusters, since the history of their formation and life is different.
On fig. Figure 3 shows the known relationship between black hole masses and stellar velocity dispersion.
The dispersion is determined from spectral observations. To determine the masses of black holes, there are several methods that give fairly good estimates (uncertainties are shown by the "whiskers" at the points). For example, the method of reverberation mapping or the most interesting method associated with a detailed study of the properties of the disk around a black hole using lensing data. But talking about all the methods for determining the masses of supermassive black holes would take us far away.
In addition to galaxies, points for two globular clusters and for Omega Centauri are also plotted on the graph. It can be seen that the points for black holes in clusters and in galaxies lie approximately on the same straight line. That is, the "family portrait" of black holes confirms their "kinship".
It would be interesting to see some kind of black hole activity, for example in the X-ray or infrared ranges. "Our" black hole, being a very calm monster, nevertheless betrays itself by its activity. True, the mass of the black hole in Omega Centauri is a hundred times less than the mass of the black hole at the center of our Galaxy, and, in addition, there is less gas in this cluster that could accrete onto the black hole. So the observational manifestations of a freshly discovered hole will most likely be weaker - it’s not for nothing that no manifestations of the “monster” have been noticed in all the years of research into Omega Centauri. But since there is a motive for a deeper search, something similar may be discovered in Omega Centauri. After all, now the real hunt for an outlandish beast will begin.
