Comets!

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Comet Swift-Tuttle

It’s a bird!? It’s a plane!? It’s a comet! A comet is a small solar system body that is made up of frozen gasses and dust. Comets orbit the sun and are heated up causing them to release dust and gases, giving a comet a visible tail. Comets are frequently confused with asteroids and meteoroids, but they have very different characteristics. Asteroids are basically big rocks that are in orbit around the sun. The major difference between asteroids and comets is the tail. Asteroids do not release gas, since they are not made of ice. Meteoroids are similar to asteroids, only much smaller. Comets are truly unique in the solar system, and can likely be found in the Kuiper belt and farther in the Oort Cloud. It is estimated that there are billions of comets in our solar system, but there are only about 3,500 known comets. Keep an eye out, and maybe you will be lucky enough to see one!

The Future of Space Travel

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Shuttle Launch

Space exploration is something that intrigues us all because, as Star Trek coined many years ago; “Space: the final frontier… To boldly go where no man has gone before”. We’ve traveled to space many time before, with the Apollo 11 moon landing being one of the most famous expeditions. This trip was so famous because it was the first time anyone has ever stepped food on another celestial body other than Earth. However, since then, we have not stepped foot anywhere else. So what is the next place mankind will go? According to Elon Musk and SpaceX, Mars is our next destination. We have already sent objects to Mars, such as the Mars Rover, but now it is time to send people to Mars. SpaceX intends to send send a cargo mission to Mars in 2022, with a second cargo and crew mission in 2024. There are a ton of ethical questions that come with travel like this, but only time will tell of what is to come next.

The Energy within the Sun

Nuclear Fusion in the Sun

The sun is a main sequence star, which means it is powered through the process of nuclear fusion. Nuclear fusion is the process of multiple (two or more) nuclei combining to form a completely different nuclei. This process occurs under extreme conditions and releases immense amounts of energy.

The sun, at its core (literally), is just a ball of burning gas. The core of the sun is made up mostly of hydrogen atoms, which are just lone protons, and the heat of the sun cause these hydrogen atoms to fuse together and turn into helium atoms. This process emits a tremendous energy. The heat and light that the sun sends across our solar system is the result of energy radiated from its core.

The sun emits astronomical amounts of energy, and does not destroy the solar system in the process. So, why don’t we try to replicate this power on Earth? Well, fusion power has been an idea since the 1940’s. The issue with it, is that nuclear fusion can only occur under extreme temperature and pressure. The sun does this naturally, but for these conditions to be possible on Earth, it requires a ton of energy. We use electrical energy to create the conditions to produce nuclear energy. Since, these conditions are so difficult to obtain, there is actually a net negative energy output while trying to start the nuclear fusion process. Although it is not practical yet, I am hopeful that one day we will be able to replicate the sun’s energy source, and feasibly have fusion power on Earth.

Celestial Navigation: How Our Ancestors Used to Travel

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Earth’s Celestial Sphere

Before the time of GPS, and all the modern forms of navigation we use today, people used to travel with the stars. Through the use of angular measurements, the sun, moon, planets, and stars could be used to find a position on earth. By looking at the angles between these celestial bodies the horizon, and your current location, you can find your position on the earth. This information allows you to pinpoint where you are and plot a course for where you want to go. Celestial navigation was a way to travel from point A to point B that relied strictly on what you were able to see and your environment around you. As a result, it is still a practice used today by groups such as the navy. It is a reliable means of navigation that does not depend on modern technology, such as electricity. Although, we have forms of navigation that are much more accurate, celestial navigation can be depended on when you have nothing else available. It is good technique to learn because, as the aphorism goes: “If it ain’t broke, don’t fix it”. The stars are not going anywhere anytime soon, so we might as well use them to our benefit.

Historical Astronomers in Context

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Wikipedia

Galileo Galilei was born on February 15, 1564 and died on January 8, 1642. During his lifetime he made monumental contributions to the world of astronomy. He did not invent the telescope, but he made improvements to it and this allowed him to observe the universe, like no one had ever done. Some of the things that he observed was the 4 moons of Jupiter, craters on the moon, the phases of Venus, and much more.

While Galileo was busy making contributions in the world of science, so much was going on around him. During his lifetime, Jamestown, Virginia was settled by England, setting up the first, permanent English Colony in North America. Also, the King James version of the Bible was created. This is also a major event because that version of the Bible is still used by the Catholic Church today! So much was going on at this time, it was really jammed pack with events. Along with all these event, many other significant figures were around during this time. For instance, William Shakespeare was actively writing and becoming one of the greatest authors in the English language. It really puts time into perspective when you realize how much is going on at any given moment.

It is absolutely crazy when you look back into time and see how much was happening at once. It is still like that today, history is literally being created every day. I always enjoy thinking of this in terms of the Cosmic Calendar. The entire history of human civilization has only been the last few seconds of the last day of the year. It is amazing when you think about how much happens in such a short amount of time, relative to the age of the universe.

The Cosmic Calendar

Wikipedia

The Cosmic Calendar is the life of the universe condensed into a calendar year. It begins on January 1st at midnight and ends on December 31st just before midnight. The noteworthy time on this calendar is 8pm on December 1st: the start of human life. The universe is approximately 14 billion years old, so humans have only been alive for an extremely small portion of this time. Neil deGrasse Tyson hosted a documentary, that describes the life of the universe in detail and I highly recommend that you watch the documentary if you want to learn more about the Cosmic Calendar!