Previous month:
March 2021
Next month:
May 2021

April 2021

Current Events: The Tides of the Moon and the Suez Canal

By Stacy Palen

How delightful! The phases of the Moon were in the news in late March, giving all of us an opportunity to teach students about the practical applications of astronomy in the modern world. You will likely recall the giant container ship that was stuck in the Suez Canal for almost a week, disrupting supply chains around the world. The arrival of spring tide helped float the ship off the bank where it was wedged, setting it free.

CNN reported about this news, although there are other outlets as well. 

I have included some snippets about this news with some questions on my final exam, asking students to sketch the relative positions of the Earth, Moon, and Sun during spring tide, and to make a sketch that demonstrates why so-called “supermoons” result in extra-high spring tides. Sketches like these are very quick to grade, so I like to use them during any times of the semester when I have a large grading load.

I can also code these questions as addressing the “Science and Society” general-education learning outcome, so that the crowd that does our general-education assessment will be able to check the box on their report.

I have in mind that I could build an entire assignment around this event, for future semesters, but I haven’t done it yet. Like you, I am just trying to put one foot in front of the other to get to the end of this semester!

Current Events: NASA Releases Stunning Hi-Res Photos of Jupiter's Swirling Atmosphere

By Stacy Palen

Sometimes, you just want to look at a lot of pretty pictures. Juno’s got ‘em. This is a nice intersection of science and society because there are issues of intellectual property rights here that can prompt students to think a little more deeply about who owns science and scientific data.

Below are some questions to ask your students based on this article.

1). What is a “citizen scientist?”

Answer: A citizen scientist helps scientists analyze raw data or produce images from raw data.

2). The images shown in the article have been processed to create “visually pleasing work for the public.” Click through to the dedicated Juno website to look at a few raw images. How do these processed images differ from the raw images?

Answer: The processed images have much greater contrast and are more colorful. The colors are often changed.

3). What information is lost when the images are processed in this way, and what information is made more available? 

Answer: Information about composition is lost, especially if the color is changed, but information about wind patterns is enhanced and made more visible.

4). Is it “honest” to process images in this way and present them as images of Jupiter?

Answer: Answers vary.

5). Are these images art, science, or something in between? Support your answer with an argument about the purpose of art and/or science.

Answer: Answers vary, but something in between is most likely.

6). What is the benefit of making “visually pleasing work for the public?”

Answer: Answers vary, but I expect to see something about public support for science.

7). You may have heard the term “intellectual property”; this is the concept that gives rise to copyright law, for example, where artists and writers own their work. Historically, images from NASA spacecraft have been part of the public domain—because the public paid for the spacecraft, they own its products, and anyone could use them to make posters or T-shirts. These images, though, have a more complicated origin. The raw data comes from the spacecraft, but the processing has been done by an unpaid graphic artist who has done something absolutely unique with each image. Who do YOU think “owns” these images: the public or the artist?  Explain and support your viewpoint.

Answer: Answers vary, but I’m looking for something “well-reasoned and insightful.”

Current Events: Hubble Uncovers Concentration of Small Black Holes

By Stacy Palen

Astronomers have long been on the hunt for “intermediate-mass” black holes. These are black holes with masses between a few hundred and a few ten-thousands of solar masses. It was thought that these should exist in globular clusters. While looking for these, astronomers have instead found a swarm of smaller black holes, forming a mini-cluster in the center of a globular cluster!

Below are some questions to ask your students based on this article.

1). What is the approximate range of masses for an intermediate-mass black hole?

Answer: Tens to hundreds of thousands of solar masses.

2). How old is this globular cluster? 

Answer: This globular cluster is almost as old as the universe itself, so nearly 13.7 billion years old.

3). How do astronomers find the age of a globular cluster?

Answer: They make an H-R diagram and find the main-sequence turnoff.

4). How does the team of astronomers from the IAP know that there is not one single black hole at the center, but rather a swarm of black holes?

Answer: The shape of the orbits of nearby stars shows that the mass at the center is extended in size, rather than point-like.

5). How do they know that those masses in the core are black holes and not stars?

Answer: They used the theory of stellar evolution, combined with the fact that the mass is invisible.

6). Why are all the black holes in the cluster found near the core?

Answer: Because of dynamical friction, where they lose momentum to other less-massive stars.

7). How might astronomers further test this idea about the core of this globular cluster?

Answer: Mergers of these black holes might be detected by LIGO/VIRGO.