Before this conceptual objective, I really never thought about the scale and size of the universe. In my head, everything just summed up to be very, very big. Just thinking about the Sun’s size and how big it is compared to the Earth is already mind-boggling, but recently I found out that our G2V star is actually on the smaller, low-mass scale. Talk about mind-blown. To take this a step further, in this conceptual objective, we focused on the size and structure of the Milky Way. In perspective of our galaxy, as we learned in a lecture tutorial, Milky Way Scales, the Sun is like a grain a sand plotted approximately 25,000 light years away from the center of our galaxy. It’s nothing, like a speck of dust!
Tha galaxy is a fascinating place and in “Hubble’s most galactically-amazing photo yet“, it’s revealed that scientists are currently doing everything they can to model what the Milky Way would actually look like. From what we learned in class, it’s really hard to study our own galaxy because we’re living inside of it. As stated in the article, scientists would have to send a spacecraft “millions of light years [from] its former home” to capture a picture. It already takes us 9 years to get to Pluto so to travel light years away to get a better look of the Milky Way is certainly not happening anytime soon. What is happening, however, is that scientists are able to learn more about our galaxy by looking at other galaxies, as well as looking at the patterns of the universe and making inferences/predictions (with evidence of course) on how our galaxy functions. The article mentions by looking at two distant galaxies, “[it] offers a glimpse of what our Milky Way galaxy would look like to an outside observer.”
The Milky Way is, unfortunately, not really made up of milk, but millions of solar systems. Astronomers estimate that the Milky Way harbors several billions of stars. Although we can’t really see it for ourselves to be sure, by studying distant galaxies we’ve been able to learn more and more about our galaxy. We measure the distance from us to globular clusters just outside of the Milky Way as well as the distribution of hydrogen gas to be able to estimate the size and structure of the galaxy. From research, we’ve been able to match up our findings of other galaxies with our own, finding that the Milky Way is spiral shaped and is approximately 150,000 light years in diameter. In the spiral’s arms, there are active star formation, giving the galaxy a bluish tint to it, while at the very center, the nuclear bulge, there are older stars. Also, by looking out and viewing the globular clusters that orbit our galaxy, it can also tell us the mass of the galaxy. This follows the same method of finding different masses of celestial objects that we learned in previous conceptual objectives.
Learning about the structure and size of the galaxy, it really makes me appreciate the work astronomers do. As you can already tell, the universe is a vast, vast place and the Earth is microscopic in comparison, yet we’ve already been able to spot distant solar systems like the Trappist-1 and distant galaxies like NGC 4302 and NGC 4298. With the advancement of modern technology, we’ve been able to accurately study the “spiral nebulas” and derive more information from celestial clusters. As we continue to look up and out with Hubble, we’re going to continue to make great discoveries, even if it’s just one star at a time.