Current Event: “Cosmic Census Finds Billions of Planets That Could Be Like Earth”

The article I read is on the recent discovery of as many as 40 billion planets in our galaxy that could have Earth-like qualities, meaning they have the possibility of sustaining life that resembles life on Earth. The data that supports this theory comes from NASA’s Kepler spacecraft, which was launched in 2009 to perform a type of “cosmic census,” recording the brightness of different, far-away stars. Erik Petigura, a graduate student at the University of California, Berkeley, was the one who made the calculations, with supervision by Geoffrey Marcy, also of the University of California, Berkeley. Mr. Petigura discovered that of every five sun-like stars in the galaxy, one has an Earth-size planet circling in a zone where temperatures would support the existence of liquid water. He also had help from a report written earlier in the year by David Charbonneau and Courtney Dressing, both of whom work at the Harvard-Smithsonian Center for Astrophysics. Charbonneau and Dressing discovered that about 15 percent of red dwarf stars have Earth-like planets in their habitable zones; Petigura now has revised this previous calculation to about 22 percent, depending on how you define the habitable zone. Considering there are 200 billion plus stars that exist in the Milky Way galaxy, this leaves a large number that have the possibility of supporting planets that are like Earth. However, these planets may still have conditions that would not support Earth-like life. For example, since no one knows what the masses of any of the newly discovered planets are, it is also unknown whether they are rocky (like Earth), or icy, or gassy. Just this last week, an Earth-size planet named Kepler 78b with the same density as Earth and an orbit of 8.5 hours was discovered, but it is infernally hot, meaning it can’t support life. Kepler was derailed by a mechanical pointing malfunction last May and was not able to finish collecting the data it was launched to find. However, the amount of data it has already collected will take another year to analyze, according to the scientists on the project. Although much is still unknown about this new discovery, Mr. Petigura’s work is backed up with data that he has done himself, as well as with the previous discoveries of other scientists.

            This article is relevant to our society because if habitable planets that are within our ability to travel to were to be discovered in the future, it could have a life-changing effect on Earth as we know it. This scenario is obviously very unlikely to occur within our lifetimes, and so would not have a direct effect on us. However, it is still important for us to learn about these new discoveries, if only to remind us that we are part of a much bigger picture. By learning about these planets that in fact might be just like Earth, we can be reminded that Earth is simply one planet in a very large galaxy. In terms of the distant future, these planets could be vital in the survival of humans if global warming keeps getting progressively worse, as it has been in recent years.

            This article fascinated me, because I had never before considered that human-like life could exist anywhere but Earth. This article offered a whole new perspective for me. I thought that it was well written and not too complicated to read, because I understood most of the scientific terms that the author talked about. I thought that a major strength of the article was that it drew the reader in with the intriguing title and first few sentences. After reading just the first paragraph I was very interested to learn more about the topic. One of the weaknesses of the article I thought was that it didn’t give a ton of information on these newly discovered planets. The article elaborated a lot on the data collecting process and spoke of past discoveries, but didn’t identify much information on the 40 billion newly discovered Earth-like planets. However, overall I thought that it was a very captivating article as well as topic, and I can’t wait to learn more about it.

Overbye, Dennis. "Cosmic Census Finds Billions of Planets That Could Be Like Earth." New York Times 4 Nov. 2013. Harvard Smithsonian Center for Astrophysics. Web. 4 Nov. 2013.

http://www.nytimes.com/2013/11/05/science/cosmic-census-finds-billions-of-planets-that-could-be-like-earth.html?ref=science&_r=0