The Milky Way Feasted on a Smaller Galaxy 10 Billion Years ago

Isabella Bouvard

Core Biology 10H|Block C-Odd/Mr. Ippolito

11/7/18

Current Events #7

Grossman, Lisa. “The Milky Way Feasted on a Smaller Galaxy 10 Billion Years Ago.” Science News, Magazine of the Society for Science & the Public, 1 Nov. 2018, www.sciencenews.org/article/milky-way-feasted-smaller-galaxy-10-billion-years-ago.

In this article, Lisa Grossman describes the research that was recently conducted as to the Milky Way’s inhabitants. It was concluded that the Milky way, during its younger days, devoured a smaller galaxy. Two research centers were used in order to conduct this study, one in space and one on Earth. Amina Helmi of the University of Groningen in the Netherlands analyzed the speeds and positions of tens of thousands of stars in the Milky Way within about 33,000 light-years of the sun, using data from the European Space Agency’s Gaia space telescope. This is a space observatory of the European Space Agency designed for astrometry. Based on this data, it was calculated that a group of about 30,000 stars seemed to be moving in the opposite direction, instead of rotating around the galactic center with the sun and the rest of the stars in the Milky Way. This was continued at the Apache Point Observatory Galactic Evolution Experiment, or APOGEE, which was conducted in an astronomical observatory in New Mexico. It used the spectrum of light that stars emit to infer their chemistry and ages. The stars that had been previously measured by the Gaia telescope were further inspected, and it was observed that the backward-moving stars had fewer heavy elements than stars like the sun. “It was just so clean. You immediately knew these stars really formed elsewhere.” Helmi notes. The final conclusion of the research was that this collision occurred ten billion years ago and explains why the Milky Way is currently split into different components. The galaxy was later given the name of Gaia-Enceladus, after a Greek Myth describing a giant buried under a large mountain in Italy.

Lisa Grossman provides very useful insight into the galaxy that our earth inhabits. The study conducted serves as a foundation of new knowledge in terms of the Milky Way. There is so much that surrounds our Earth that we have yet to discover, and this advancement broadens our spectrum of how we understand the universe. This might cause humanity to invest more into space exploration, as we now know that our galaxy contains so much more than we originally intended. While we have only recently discovered that these two galaxies once merged, it gives ordinary people much more of an idea based upon the possibilities of our universe and reasons as to why we should continue to explore it. This also might give us insight as to additional galaxies that are elsewhere in the universe. I think that it is important that we have the ability to be aware of our surroundings, not just speaking in terms of the environment but the galaxy that surrounds us.  

In general, I think the author did a very good job of providing the right amount of information to get the point across to the reader. Grossman provided multiple quotes from the experiment itself that makes it less difficult and very clear for the reader to understand. Her writing is very sophisticated, as this topic is not an easy one to explain while making the article very interesting. However, I feel as if there are a few areas in which Grossman can improve upon. When reading about the Gaia space telescope and the Apache Point astronomical observatory, I was confused as to what each of them meant while she did not provide direct background information. In order to obtain the correct definition of each of these, I had to do further research. I feel like if this information was included, it would make it easier for the reader to understand. Although Grossman generally did a good job of explaining certain terms, both of these were crucial to the experiment and it would really enhance her writing if such background information was included. Also, the general organization of the article was not as refined, and sometimes when mentioning a new topic the author seemed to discuss another topic in the next paragraph about something discussed prior in the article. This could be fixed simply by switching the order of some of this information or making it more concise. Overall, this article was extremely interesting to review and I hope to see where this new research takes route in further studies.