Tag: corona

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Interesting Sun Facts

Interesting Sun FactsWe all know some things about the Sun. We know it is powered by thermonuclear fusion, that it is a G-2 type spectral star, and that it is the primary energy source for the Earth. Many of us have seen a solar eclipse when the Moon blocks out the photosphere of the Sun and lets us see its corona. We know that the Sun is not just a ball of fire but a complex globe. Here are some more interesting Sun facts that are relatively new to us:

The light that we see coming from the Sun is from its photosphere. The photosphere is a thin incandescent layer that is just 200 miles (322 km) thick. That is less than one four-thousandth of the Sun’s diameter and is like the outer skin of an onion, only thinner than that.

The energy of the Sun is created in its core, which is a very small sphere, just one two-hundredth of the Sun’s volume. Every second that small ball emits the energy of 96 billion 1-megaton hydrogen bombs. The Sun’s weight decreases by 4 million tons every second as mass is turned into energy and radiated from the photosphere.

The Sun spins on its axis once a month, just as the Moon does. The center 70% of the Sun spins uniformly like a solid ball. The remaining 30% has different spins with the poles turning more slowly than the equator. These zones spinning at different speeds meet in a recently discovered zone 130,000 miles (209,000 km) below the surface. That zone is called the tachocline, and it’s where the Sun’s magnetic field originates.

Sunspots are areas where the local magnetic field is 5,000 times stronger than on the rest of the surface. The stronger magnetic field constricts the Sun’s plasma. When sunspots are rare, it seems that Earth’s climate becomes colder. Starting in 1645 there were few sunspots for 70 years. During that time, Earth became colder, people abandoned fishing colonies in Iceland and Greenland, and the Thames River and Venice canals went through periods of freezing solid.

As scientists probe more in-depth, they learn many interesting Sun facts. Just as in many other areas, the more we learn, the more questions we have. What effect do sunspots have on life on Earth? How can they affect our climate? What will happen in the next sunspot cycle? Tomorrow, we will look more into questions about sunspots. As we learn more interesting Sun facts, we realize the amazing design wisdom of the Creator to make life on this planet possible.
— John N. Clayton © 2019

Data from Astronomy magazine, July 2019, page 20.

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Opportunity of a Lifetime Experience

Opportunity of a Lifetime
On August 21, there will be an opportunity of a lifetime for many people across the United States. They will get to see a total solar eclipse! This will be the first total eclipse of the Sun visible in the continental United States since 1979 and the first to cross the country since 1918.

The total solar eclipse will begin its travel on land on the west coast of Oregon and move at about 1800 miles per hour to the east coast of South Carolina. Because the Moon moves across the sky from east to west, the shadow will move from west to east crossing the country in about an hour and a half. It will be total for only a little more than two minutes at any location on the path of totality. The path will be about 70 miles wide through the center of the country.

A total eclipse is much different from a partial eclipse. On a clear day with a 90 percent eclipse coverage, the Sun would still be brighter than on most cloudy days. Even a 99 percent eclipse does not have the same impact as a total eclipse. When the Moon completely blocks the Sun, it will be like nighttime. When this eclipse is at totality, Jupiter, Mercury, Mars, and Venus will be visible along with bright stars.

The most impressive sight will be one that you can only see during a total eclipse—the Sun’s corona. The corona contains particles of matter ejected from the Sun and traveling thousands of miles out into space. The particles follow the magnetic field of the Sun, and they are constantly changing with that field. The corona is always there, but it’s normally blocked from view by the scattered light in Earth’s atmosphere. Even though the corona is much dimmer than the surface (photosphere) of the Sun, it is many times hotter.

This is also the opportunity of a lifetime to see the darkness of night in the middle of the day. Looking around on the ground during totality, animals and insects may begin their nighttime activities. There will only be a 360-degree sunset-like glow on the horizon from refraction of sunlight outside of the full shadow (umbra) of the Moon.

For the moments of totality (in this case a little more than two minutes), you will be able to look directly at the Sun without special solar filters. Except for the brief time of totality DO NOT LOOK DIRECTLY AT THE SUN. Of course, if you are not in the area of the TOTAL eclipse, it is NEVER safe to look at the Sun. Many universities, libraries, and science centers have special glasses available to block the visible and UV light which could permanently damage your eyes. DO NOT USE SUNGLASSES! They will not protect your vision.
To see an animated flyover of the path of totality click HERE. To see a NASA animation of the eclipse from space click HERE. There is an interactive app that you can put on your Android or iPhone to monitor the eclipse. Just go to your app store and search for “Eclipse Safari.” NASA will be live-streaming the eclipse from across the country. You can find the live stream through Eclipse Safari or by going to nasa.gov or NASA’s YouTube channel or Facebook page.

We hope you will enjoy this opportunity of a lifetime to observe one of the wonders of God’s creation SAFELY.
–Roland Earnst © 2017

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Marvelous Coincidence or Design?

Marvelous Coincidence or Design?
Yesterday we talked about the upcoming total solar eclipse and the fact that the Moon can completely hide the Sun from view. That seems very strange since the Sun is about 390 times larger than the Moon. By a “marvelous coincidence” the Sun is 390 times farther away than the Moon. Since the Sun is 390 times farther away, it appears to be 390 times smaller. For that reason, when we see the Moon and the Sun in the sky, they appear to be the same size.

The Moon can exactly cover the Sun’s disc which we call the photosphere. At the same time, in a total eclipse, we can see the chromosphere, which is the very bright atmosphere surrounding the Sun. We can also see what is called the corona–jets of hot gas which follow the lines of the Sun’s magnetic field. Under normal circumstances, the chromosphere and corona are invisible because of the glare from the photosphere.

Scientists have learned much about the Sun by studying what we can see only during total solar eclipses. Only during a total solar eclipse can scientists study the “solar wind” which sends out streams of particles called coronal mass ejections (CME). CMEs can travel all the way to Earth and knock out communication satellites or terrestrial power grids. Just as scientists work to predict weather on Earth to avoid catastrophes, they want to learn how to predict CMEs to prepare for something that could potentially knock out power or communication to large areas of our planet.

Scientists have also learned some interesting things about the Sun’s temperature during total eclipses. They had measured the temperature of the Sun’s surface to be 6,700 to 11,000 degrees F (3,700 to 6,200 degrees C). However, by observations made during total eclipses, they found that the temperature of the chromosphere is up to 14,000 degrees F (7,700 degrees C) and the corona is 3.5 million degrees F (2 million degrees C)! They are still trying to discover how that is possible.

Was it mere coincidence that the Moon can exactly cover the Sun? We think that God designed it that way so that we can learn how “the heavens declare the glory of God” (Psalms 19:1). We think it is not just a “marvelous coincidence,” but another example of wisdom and purpose in design. Tomorrow we will tell you about what is probably the most significant scientific discovery made during a total solar eclipse.
–Roland Earnst © 2017