Fun With the Sun Trivia Quiz

Answer: 4.5 billion years

There are various ways that scientists can use to determine the age of the sun. One way is to determine the age of the Earth. It is believed that the Earth and the sun formed at the same time. Using trace amounts of radioactive isotopes found in the Earth's crust, as well as meteorites, scientists can calculate the half-lives of the radioactive elements, and analyze how much remains, and determine a fairly accurate age estimate.

Another way to estimate the age of the sun is to measure the rate at which it is converting mass to energy, and then look at the elements that make up the sun. Most scientists believe the sun and the solar system were formed about 4.5 to 4.6 billion years ago.

Answer: It is composed partly of material from earlier stars

Our sun is basically a very large ball of gas; it consists of about 74.9% hydrogen, and about 23.8% helium. The remainder is composed of heavier elements. The sun contains a very high amount of these heavier elements; they could not have been formed inside a star the size of our sun. Most scientists believe that one or more massive supernovas - the explosion of stars many times larger than our sun - occurred in our area of space at the time of our sun's formation, and that the sun incorporated some of the elements released by these earlier stars. That means that much of the material in the sun, and in our world, including our bodies, may have at one time been part of a giant star that no longer exists!

Answer: False

Our sun is classified as a "yellow dwarf," but that is misleading. The sun is actually larger and more massive than 90% of all known stars. The stars you see in the night sky, however, are almost all much bigger than the sun. Most of them are hundreds or thousands of light years away, and are only visible because of their huge size.

The vast majority of stars are red, brown, or white dwarfs, and much smaller than the sun.

Answer: Gravity

Aristotle, that old hack, really did a cop-out on this one. He said that matter in space was different than matter on earth, so the sun, "a ball of ether," could just go on shining forever. Not a very satisfactory explanation. Some thought the sun was a gigantic burning lump of something - coal, for example. But as scientists developed ways of measuring the size of the sun, and its distance from Earth, it became clear that wasn't the case. Someone calculated that if the sun were made of coal, it would have burned itself out in a mere 1,500 years.

Some scientists proposed that matter was constantly falling into the sun, and that the energy of these impacts kept the sun shining. The problem with this theory was that 100 trillion tons would have to crash into the sun every hour (!), and there didn't seem to be that much matter available. Furthermore, this would have resulted in an increase in the sun's mass, and also its gravity, which would have caused Earth's year to shorten. This obviously wasn't happening.

In 1854, a German scientist named Hermann von Helmholtz proposed that the sun was shrinking under the force of its own gravity. He calculated that if the sun shrank at the rate of one inch every three hours, enough energy would be released to keep the sun shining for 30 million years. This theory was generally accepted up until about 1920, when Francis W. Aston discovered that a helium nucleus weighs less than four hydrogen atoms. This led another British scientist, Sir Arthur Eddington, to propose that the sun could shine by converting hydrogen atoms to helium.

Answer: Nicolaus Copernicus

Some ancient Greeks, notably Aristarchus and Seleucus of Seleucia, had argued for the idea that the Earth orbits around the sun, but the Earth-centered, or Ptolemaic system, won out. This placed the Earth at the center of the universe, and declared that everything else - the sun, moon, planets, and stars - revolved around it. In order to make make this theory fit the observed motion of heavenly bodies, a very complex system of orbits was necessary.

In 1543, Polish astronomer Nicolaus Copernicus published a book called "On the Revolutions of the Heavenly Spheres," which postulated that the sun, not the Earth, was the center of the solar system. Copernicus' ideas were slow to catch on, but when telescopes were invented and it was found that planets move in ellipses instead of circular orbits, it became clear that Copernicus was right.

Answer: 11

When early astronomers began looking at the sun through telescopes, they saw blemishes on its surface - dark areas they called sunspots. Eventually, it became clear that the number of sunspots varied in a regular 11 year cycle. When there are a lot of sunspots, the sun radiates more energy.

When there are fewer sunspots, it radiates less. The sun's energy output varies by about 0.1% to 0.3% over one of these cycles. Some scientists believe that there may be other, longer cycles that affect solar activity. From about 1300 to 1870, temperatures were much lower than they are now.

This period is sometimes called "the Little Ice Age." Some scientists believe a decrease in solar radiation of about 0.6% may have caused it. In a similar vein, some scientists attribute so-called "global warming" to solar activity rather than greenhouse gasses, although they are in the minority at present.

Answer: 99.86 %

Almost all of the matter in the solar system is concentrated in the sun. The Earth, the other planets, and all other solar bodies are just insignificant leftovers.

Answer: 60 light years

The brightness of stars is measured in orders of magnitude; the lower the magnitude, the brighter the star. There are two types of magnitude: visual magnitude and absolute magnitude. Visual magnitude is a measure of how bright an object looks to an observer from a particular point in space. The sun appears very bright because it is so close to us; the sun's visible magnitude is -26.74. The visual magnitude of the brightest full moon is about -12.7. The mathematics are too complicated to explain here, but the scale is not linear; a difference 14 degrees of magnitude means that the sun appears about 400,000 times brighter than the brightest full moon when viewed from Earth.

Absolute magnitude is a measure of how bright various stars would appear if they were viewed at a distance of ten parsecs (32.6 light years). The absolute magnitude of the sun is 4.83. If it were viewed from a distance of 32.6 light years, it would be a faint, but easily visible star. By way of comparison, at that distance the sun would be about as bright as the fainter stars that make up the Little Dipper, or Ursa Minor. Assuming there was nothing to block its light, the sun would continue to be visible to the naked eye up to a distance of about 60 light years.

Answer: Leo

Each of the signs of the zodiac has a heavenly body that is said to "rule" that sign. There aren't enough planets and luminaries to go around, so some signs have to share; for example, both Aries and Scorpio are ruled by Mars. But the sun is the exclusive property of Leo. Leo, not surprisingly, is a fire sign (the other fire signs are Aries and Sagittarius). Leos are supposed to be vain, outgoing, generous, and love to be the center of attention.

In the twenty-first century, very few people take astrology seriously, but in medieval times it was regarded as a real science.

In Elizabethan England, casting the Queen's horoscope was a capital offense!

Answer: It will become a white dwarf

Scientists have a fairly good idea of what will eventually happen to the sun. It will continue on the "main sequence" for another five billion years or so; in other words, it will continue to exist as it is now for many billions of years. Eventually, the sun will exhaust its supply of hydrogen, and start fusing helium into heavier elements. When this happens, the sun will cool and begin to expand; it will eventually become so large that it will swallow up the inner planets (maybe even the Earth). The sun will lose much of its mass, and eventually collapse to form a white dwarf star, which will endure for trillions of years before fading out completely.

The sun is not large enough to explode as a nova or supernova, or form a black hole.