Giuseppe Bertini, Galileo Galilei Showing the Doge of Venice How to use the Telescope, 1858.
Credit: Wikimedia Commons.
… for the Galaxy is nothing else but a mass of innumerable stars planted together in clusters.
—Galileo Galilei, Sidereus Nuncius (Starry Messenger), 1610
Ancient astronomers constructed explanations of the motions of the celestial bodies based on mathematics, philosophy, and careful observations of the skies as visible to the human eye. They recorded the positions of these heavenly bodies over time. Based on this method, ancient astronomers concluded that Earth was the center of the universe and that all other objects in the sky revolved around it.
In the 2nd century CE, a Roman astronomer named Ptolemy refined this view, stating that all planets moved in perfect circles, attached to perfect spheres, all of which rotated around the Earth: a theory that predicted the paths of the planets fairly well. This view, accepted for 1,400 years, was challenged by new astronomers, aided by instruments that enabled them to see the skies as they had never been seen before. Chief among them was Galileo, bolstering his observations with a revolutionary telescope he invented.
He carefully explored the night sky, turning his telescope to what looked like “dark” parts and discovering that they were filled with stars too dim to be seen without the telescope’s enhancement. In 1610, he published his observations of the solar system and distant stars in a volume called Sidereus Nuncius, or Starry Messenger.
In this lesson, students will practice close reading of passages from Galileo’s Starry Messenger concerning his observations of the stars and constellations through a telescope. They will develop an understanding of how he constructed his arguments to challenge the established views of his time using new technology and logical reasoning.
At the end of this lesson students will be able to:
CCSS.ELA-Literacy.CCRA.R.1: Read closely to determine what the text says explicitly and to make logical inferences from it; cite specific textual evidence when writing or speaking to support conclusions drawn from the text.
Science and Technical Subjects:
In addition to addressing content in Earth and Space Science as articulated in the Next Generation Science Standards, the lesson also supports the development of ideas pertaining to Scale and Proportion, one of the NGSS’s crosscutting themes. For example, in Starry Messenger, Galileo reported that he saw at least ten times as many stars through the telescope as with the naked eye. From his observations he deduced that the nebulae and the Milky Way were collections of stars too small and far away to be seen as individual stars by the naked eye.
This lesson also helps to support the development of the following science and engineering practices as articulated in the National Research Council’s A Science Framework for K–12 Science Education:
Prerequisite skills: By the end of Grade 5, students should know that stars range greatly in size and distance from Earth and this can explain their relative brightness. You may wish to review these concepts with the class before beginning this lesson.
Students utilize close reading strategies, using passages from Galileo’s Sidereal Messenger (Sidereus Nuncius) in which he records his early observations of the moon, the stars (the belt of Orion and the Pleiades), and the moons of Jupiter. The science content will focus specifically on the stars and constellations. The student activity version (Launchpad) may be used to guide students through a sequence of activities outlined below. The activities may be taught with or without this aid.
The teacher may also wish to give students a brief explanation concerning the Sword and Belt of Orion, which Galileo mentions in Section 5 of the close reading of Activity 2. The Star Search interactive for Orion from the AAAS’s Science NetLinks may also be used.
Other Tools and Worksheets
Lesson Extension (Optional)
This activity is designed to introduce students to the general state of astronomy up to the time of Galileo. Students listen, look, and read the text of the Stargazing video closely to discover key concepts and vocabulary as they progress.
The following questions for students after viewing the video necessitate an understanding of the academic vocabulary listed on both the teacher and student versions of the vocabulary handout.
Bridge to Activity 2.
In order to bring together what students have learned through the video about the state of astronomical observation and the close reading of Starry Messenger in Activity 2, assign a short homework assignment in looking at the night sky.
To help students gain an understanding of key scientific terms and concepts, as well as integrate textual and visual information, the teacher will model a guided close reading activity using the first of seven sections from Galileo’s Starry Messenger, which deals with his observations of the stars through a telescope.
Suggested reading methods are given in the teacher’s version of the close reading. The teacher may also wish to give students a brief explanation concerning the Sword and Belt of Orion, which Galileo mentions in Section 5 of the close reading. (Note: vocabulary items appear in most of the focus questions and on the teacher’s and student’s vocabulary lists.)
Have the students as a group think back to the state of astronomy before Galileo in Activity 1, and compare that to what he has noted here about the nature of the stars as seen through a telescope (as opposed, for example, to the planets). Ask them to write down some examples from the text that point to his overall argument for using such a scientific device. Encourage the class to refine their own answers and come to consensus about the best responses to the questions
Student will compare and contrast their knowledge about the Pleiades gained from a NASA photograph with that gained from Galileo’s drawings and descriptions of them in the Starry Messenger. The goal is to engage them in an analysis of the accuracy of the astronomer’s conclusions about these systems.
Have students use the star comparison graphic organizer, (also available from the student Launchpad), to compare and contrast Galileo’s drawings of the Pleiades system with the NASA photograph taken using modern space telescopes. (Optional vocabulary appears in the teacher’s and student’s vocabulary lists but not on the Launchpad.)
Ask students to individually write a short paragraph stating how accurate Galileo was in his conclusions about the placement of the stars; their scale, and clarity, based upon modern astrophotography.
Students will incorporate their comparison of images from Activity 3 into their comparison of a news release from a NASA story about the Pleiades (“Hubble Refines Distance to Pleiades Star Cluster”). This story presents new scientific information about measuring distances to distant stars developed as a result of analysis of images from the Hubble Space Telescope. It will serve as a comprehensive review of student’s general understanding of measurement and distance obtained through their comparisons of the close reading with the drawing and the photograph.
After reading the news story, have students comment about the progress of astronomical observation by writing a short (one- to two-page) analysis comparing the current state of knowledge regarding the Pleiades nebula to what Galileo wrote in the passages from Sidereus Nuncius in Activity 2. Remind them to incorporate their comparison of images from Activity 3.
Working with the constellation Orion presents a visually more challenging extension of the culminating activity of this lesson and will deepen students’ skills in analyzing complex scientific media and in making more subtle observations about the actual state of galaxies, with their dust and gas clouds.
This activity should be done by pairs of students or by individual students.
Instruct students to read the NASA story about the Orion nebula (“Hubble Panoramic View of Orion Nebulae Reveals Thousands of Stars”), which presents new scientific information on the density and variety of stars in the Orion nebula developed as a result of analysis of images from the Hubble Space Telescope.
After reading the news stories, have students comment about the progress of in astronomical observation of the understanding of the constellation by writing a short (one- to two-page) analysis comparing the current state of knowledge regarding the Orion nebula to what Galileo wrote about the constellation in the passages from Sidereus Nuncius in Activity 2. Instruct students to incorporate their comparison of images from the earlier part of this extension activity.
3 class periods