Astronomers May Have Spotted the First Known Exoplanet in Another Galaxy

 

Kailee Fino

11/1/21

Mr. Ippolito

Chemistry 9H

Grossman, Lisa. “Astronomers May Have Spotted the First Known Exoplanet in Another Galaxy.” Science News, Science News, 29 Oct. 2021, https://www.sciencenews.org/article/first-exoplanet-discovery-outside-milky-way-galaxy-astronomy. 

While we have discovered many planets within our galaxy, it is very rare that we ever discover planets outside of it. In fact, it’s so rare that it has never happened. Until now. This week, scientists have discovered the first planet outside of our galaxy. Located in the Whirlpool (M51) galaxy, the planet is estimated to be the size of Saturn. The planet, which has been dubbed M51-ULS-1b, rotates around a two-star system in which there is a live and dead star, called an x-ray binary — which is actually how it was found in the first place. To elaborate, as aforementioned above, an x-ray binary system is a system in which there are two stars – a live star, and the remains of a dead one. In the system, The dead star, which is either a neutron star or black hole cannibalises the live star, gobbling its energy and heating it up to a point where it can, and does produce radiant x-rays, which make these systems distinguishable from other star systems. It also makes these systems ideal locations for planet hunting, because these regions of x-ray light are often so small thatsmall, that a large planet can obstruct them. This means, researchers can, through finding data pointsdatapoints in which there was an obstruction of these x-ray binaries,potentially find planets — even those as far away as those in other galaxies, like M51-ULS-1b, which is located a whopping 28 million light-years away from earth. This remarkable logic was the result of astrophysicist Rosanne Di Stefano, at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass; and her colleague, astrophysicist Nia Imara, at the University of California, Santa Cruz, who suggested that using these x-ray binaries could possibly find planets. Through use of  data collected by NASA’s Chandra X-ray telescope, which looked at three different galaxies – the pinwheel galaxy , M101; the sombrero galaxy, and M104; and the whirlpool galaxy, they were able to find one succinct datapoint of an obstruction of an x-ray binary; an obstruction that would result in this discovery. Apparently, on September 20, 2012, there had been a three hour long obstruction of the x-rays emitted by the M51-ULS-1 system; and while both Di Stefano and Amara have ruled out the possibility that the obstruction may be a gas cloud, or some other factor, some researchers believe that the discovery is rather suspect, as for it relied on a plethora of coincidences to come into fruition, in other words; a perfect storm. One scientist, or rather, astrophysicist at the Swinburne University of Technology in Melbourne by the name of Matthew Bailes points out the orbit of M51-ULS-1b being perfectly in line with earth at the exact time that Chandra was observing it. However, Di Stefano counters with the logic that the universe is vast, and that the presence and potency of intergalactic planets is immeasurable. She points out that the fact that they found a planet in such a small dataset indicates the sheer abundance of exoplanets even beyond our own milky way galaxy, and makes the probability of finding planets like M51-ULS-1b very, very high.  “Maybe we were lucky, But I think it’s very likely that we were not special. We looked and we found something because there was something to find,” admits Di Stefano. She also acknowledges the fact that seeing this particular planet is a once-in-a-lifetime event, with her focus not on re-finding this planet, but finding others like it. 

This article was a four horsemen threat in the sense that it was captivating, well written, comprehensive, and informative. It gave ample details and a more-than-adequate amount of background information about the discovery. It identified the significance of the discovery well, and explained it in detail. It cited a plethora of sources, including one that contradicted her narrative — that this was indeed the first extragalactic planet discovered. She presents the information in a manner that allows the reader to truly conceptualise the information given, and visualise the discovery, M51-ULS-1b.  She details the inner workings of the study beautifully, and in a chronological manner, which allowed me to picture the study, and make a mental timeline of the events within it. She had a relevant title image. As for the relevance of the article to science and beyond, this discovery is nothing short of massive. confirming the existence of planets outside of our galaxy is a massive discovery, though obvious. As stated in previous current events, it is discoveries like this one that help further our understanding of the cosmos, and is vital to concepts like the Drake Equation, and its response, the Fermi Paradox. In short, it may help us locate habitable planets, and even extraterrestrial life. Furthermore, the x-ray binary method conceptualized in the study could be vital to finding more planets like M51-ULS-1b in the future.   

While i have nothing but accolades for the article Astronomers may have spotted the first known exoplanet in another galaxy, by Lisa Grossman, it’s not necessarily perfect. It’s one downfall, for me, is the lack of imagery. She only uses one image, which is the cover image. This forces the reader to imagine what the study and discovery looked like; and while her words allowed the reader to do a good job at that, the lack of imagery really felt like it was a big thing missing. It felt like a hole in an otherwise perfect article, one that could have easily been filled by an image or two within the article. Images, especially those documented within the study would have made this article perfect. So, if Lisa Grossman were to change anything about the article, it would be a better utilisation of images. 

All in all the discovery, and Lisa Grossman’s beautiful article discussing it was nothing short of fascinating. The fact that a physical planet in another galaxy has been discovered is nothing short of revolutionary for science, and astronomy nerds like myself. It’s a discovery, that, theorized about in the past, to the point where it is common knowledge and regarded as fact, is finally proven to be true. The fact that such a thing was discovered is a testament to science, and its cutting nature, while also being a testament to the amazing people and instruments that brought the discovery into fruition. 

And plus, new planets are cool!