Tag Archives: Sun

The Sun is the star at the center of the Solar System. It is by far the largest object in the solar system. It contains more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest). Its diameter is about 109 times that of Earth (Equatorial radius: 695,700 km/432,288 mi, Equatorial circumference: 4.379×106 km/2,720,984.45 mi), and its mass is about 330,000 times that of Earth.

It is often said that the Sun is an “ordinary” star. That’s true in the sense that there are many others similar to it. But there are many more smaller stars than larger ones; the Sun is in the top 10% by mass. The median size of stars in our galaxy is probably less than half the mass of the Sun.

The Sun

About three quarters of the Sun’s mass consists of hydrogen; the rest is mostly helium, with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.

The Sun is a G-type main-sequence star (G2V) based on spectral class and is informally referred to as a yellow dwarf. It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense, that it eventually initiated nuclear fusion in its core. It is thought that almost all stars form by this process.

The Sun is roughly middle-aged and has not changed dramatically for over four billion years, and will remain fairly stable for more than another five billion years. However, after hydrogen fusion in its core has stopped, the Sun will undergo severe changes and become a red giant. It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury, Venus, and possibly Earth.

Planets and the sun - size comparison

Planets and the sun – size comparison

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Top 6 Biggest Stars in the Universe

What is the biggest star in the Universe? In fact, it is really hard to give an exact answer to this question since the universe is big, neighboring and the other galaxies are billions of light years away from us. But, we can give it a try. Here are the top 6 biggest stars in the Universe currently known by radius.

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Watch: what other stars would look like in the place of the Sun

The Sun is the primary source of energy for Earth’s climate system, and the life on Earth. With a diameter of about 1.39 million kilometers (864,337 miles, i.e. 109 times that of Earth), and a mass about 1.9885×1030 kg (330,000 times that of Earth, accounting for about 99.86% of the total mass of the Solar System), it may be the biggest thing in this neighborhood, but it is actually just a medium-sized star among the hundreds of billions of stars in the Milky Way galaxy. In the video published by the CAMENGAT creative astronomy below, you can see some dwarf stars and other giants compared to the Sun at the edge of its sphere: at 150 million kilometers (1 AUNotes 1) with a 50 mm objective. The stars are the Sun, Alpha Centauri A, Sirius, Vega, Pollux, Arcturus, Aldebaran, Rigel, Antares, and Betelgeuse. The scenario: Astronomical Observatory of Paranal, Chile.
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Total Solar Eclipse 2017 Images From Space

On Monday, August 21, an estimated 2 million to 7.4 million Americans traveled to see the first total solar eclipse in 99 years to go coast to coast in the United States, which went from Lincoln Beach, Oregon, to Charleston, South Carolina. But, some of them were unlucky, as the weather was overcast in some places. But, luckily for them (and for us), NASA captured some amazing and beautiful images of the eclipse and published them on their website.

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How Earth Could Die – 8 Horrible Ways

Now we’re living on a warm, hospitable planet. As Carl Sagan has said “That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.” We, humans, are the unquestionable rulers of our little oasis in a hostile universe. But all things must pass. The life on Earth, even the planet itself, won’t last forever. What’s more, the humans may go extinct before our planet (and probably before the life on it) dies out. Here some possible (and horrible) ways how planet Earth could die.

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Leaving Solar System at the Speed Of Light

Our Solar system is big, and vast, despite it is really small compared to our galaxy, not to mention the complete universe. To put this into a perspective, you can think yourself as a photon emitted by the Sun. It takes about 8 minutes to reach the Earth after a photon has been emitted from the Sun’s surface. And it takes 5 hours to get out to Pluto from the Earth. The edge of the Solar System is far beyond the orbit of Pluto.

But, where’s the edge of the Solar System? Well, It’s complicated. Informally, the term “solar system” is often used to mean the space out to the last planet – Neptune. Some scientists thinks says the solar system goes out to the Oort Cloud, the source of the comets. The inner edge of the main part of the Oort Cloud could be as close as 1,000 AU (Astronomical Unit, the distance between the Earth and the Sun, which is around 93 million miles or 150 million kilometers) from our sun. The outer edge is estimated to be around 100,000 AU.

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The Size Of Earth Compared to Other Planets and Stars (and the Universe)

When it comes to big numbers, very big numbers, the human brain is weak. In fact, our brains cannot deal with the really large numbers. That’s why when the subject is Earth, planets, Solar System, galaxies, and in general, the Universe, we cannot truly conceptualize the things. A lot of people think we’re “conquering” space (we are far, far away from that – and maybe we never will), or the “aliens” are regularly visiting Earth as if it is just an hour’s drive from there. In fact, these people don’t truly understand what are they talking about, how big is the universe, how far the stars are, and how the Earth is a tiny, tiny spot in a vast space we are still striving to understand.

But we can try to understand and conceptualize. To put things into a perspective, YouTube user morn1415 prepared a video (he updated a previous video with the new findings in the astronomy).

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Earth: a fast-moving Spacecraft

In fact, we’re all living in a fast-moving spacecraft named Earth. Our planet is moving around our sun in an elliptical (an ellipse which is very close to a circle) orbit. The Sun is (our solar system, the Sun, Earth and all the other planets and objects) whirls around the center of our galaxy. And, our galaxy and the other galaxies in our neighborhood are also rushing towards a structure called the Great Attractor, a region of space roughly 150 million light-years (one light year is about six trillion miles) away from us. This Great Attractor, having a mass 100 quadrillion times greater than our sun and span of 500 million light-years, is made of both the visible matter that we can see along with the so-called dark matter that we cannot see.

So, even when you’re resting on your armchair, you’re flying through space faster than the fastest human-made object. But how fast actually?

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