Nearby Star Hosts & Earth-Size Planets

Taylor Keck

Biology 1610

Dr. Michaela Gasdik-Stofer

March 1, 2017

            In an article found on Scientific American, astronomers have discovered a nearby star 40 light years away that is has 7 planets orbiting around it’s center. They call this TRAPPIST-1 system. They believe something amazing is happening on these planets and they believe it is nothing like anyone has heard of before. This extraordinary discovery consists of not only one, but seven planets around the same size as earth. It is believed that some of these planets could support life like earth does.

Over several of years, astronomers have searched for similar planets with rocky surfaces and atmospheres similar to ours. The atmosphere couldn’t be too thick or thin, and would have to possess the perfect amount of nitrogen, oxygen, argon, and Carbon dioxide, in order to support human life. The right amount of distance away from its center star would also need to be considered, because the ideal planet couldn’t be too hot or too cold, and would need the perfect amount of starlight. The world would need to be required to harbor and support a temperate climate in which lakes, oceans, and rivers could be made. Several planets have been considered to convey some of these characteristics and the planets in TRAPPIST-1 could be those possible earthlike structures.

Out of these seven comparable to earth worlds, three of the planets are in the habitable zone as far as temperature wise goes. All show to be the same composition, size, and mass as earth. As of now, the planets have not been name, they are only classified as planets a, b, c, d, e, f, g, and h. As the astronomers get to know the planets better and learn what they compose of, they will be able to better understand them and come up with names. They are so overwhelmed with this evidence of possible life beyond our solar system on these planets. For the first time we will have seven more terrestrial planets to study, rather than just four we already know about (Mercury, Venus, Earth, Mars). we can study and better understand what they entail. Not only do these discoveries answer scientific questions about the universe, but it will also answer many questions from philosophers, such as “how frequent life is in the universe”.

The article explained how these astronomers first found these exoplanets while using the transit technique. This type of technique measures the minute dimming of a star as planets orbit it, and during this process it detects the planets. As this orbit happens, it casts a shadow to us. We measure the size of the shadow and the diming of the star. Also measuring the density of these planets let’s astronomers know if the planet is rocky, because life cannot exist on a gaseous planet. When they found these exoplanets they determined that all of these planets are most likely rocky based on the density. They find the density of the planets as they orbit the star. There gravity pulls on each other causing them to speed up and slow down, looking at that it tells you how much mass each planet has. Once the volume and mass is determined you can calculate the density. Looking at the density of these planets, they noticed that the density is very similar to earths. Of course reading through the rest of this article, density isn’t the only important thing in determining if these planets can support life, determining if it is habitable and the gases in its atmosphere is also important. In fact, NASA will hopefully be launching a new telescope in 2018 that will allow them to look at the planets and actually measure the gases in the atmosphere.

Lots is to be done to determine more information about these planets, but NASA is very hopeful, and believes they are in a good spot. I enjoyed learning more about astronomy in this article. Usually I am not super interested in space and the all that comes with it, but it really caught my eye and I just kept coming back to this article and wanted to learn more about this subject of the new discovery on these planets. This article has definitely given me a new understanding of astronomy and all that goes into it and I found it very interesting.