This lesson provides a way for students to determine the relationship between the distance from a light source and its brightness. Once students discover the relationship, they can begin to understand how astronomers use this knowledge to determine... (View More) the distances to stars and far away galaxies. (View Less)

In this lesson, students measure the size of several galaxies to reproduce a plot of Hubble's Law. The goal of this lesson is to give students the chance to simulate the process that led to the notion that the universe is expanding, provide insight... (View More) into how this idea was reached, and inform students about the nature of our universe. This lesson is part of the Cosmic Times teacher's guide and is intended to be used in conjunction with the 1929 Cosmic Times Poster. (View Less)

In this investigation, students use "point-source" light, light meters, and graphing software to quantify the reduction in light over distance. Through careful measurement of light received at several distances, students discover the best fit of the... (View More) data is the inverse square rule. Using this rule, students then calculate the distance between the light source and the light meter at random placements. Finally, students extend this principle to model the manner in which distances to Cepheid variable stars are measured. The distance between the Cepheid (here the light source) and the Earth (the light meter) can be determined by comparing the output of the source to the amount of light received. An historic scientific breakthrough occurred when the period-luminosity relationship of Cepheids was quantified throughout the early 1900s. This breakthrough allowed astronomers to gain a more correct understanding of the dimensions of our galaxy and the universe beyond. This activity is part of the "Cosmic Times" teacher's guide and is intended to be used in conjunction with the 1929 Cosmic Times Poster. (View Less)

In this lesson, students simulate an experiment in which the discovery of dark energy can be made by plotting modern supernova distances on a Hubble Diagram. Data is provided in an Excel spreadsheet (see related resources). In order to complete this... (View More) activity, students should be familiar with Hubble's Law and the concepts of absolute luminosity, apparent luminosity, and Doppler shift (particularly redshift). This activity can be done using either a computer graphing program or manually with graph paper. This lesson is part of the "Cosmic Times" teacher's guide and is intended to be used in conjunction with the 2006 Cosmic Times Poster. (View Less)

In this two-part investigation, students explore the concept of transits. In the first part, they discover that a transit is an event where one body crosses in front of another, like when a planet goes in front of a star. In the second part,... (View More) students investigate how a planet's size and orbit affect the transit and then learn how to interpret transit graphs. Extension activities, an explanation of the mathematics used in the activity, background information, real data from NASA missions, and an answer key are included. (View Less)

In this activity, students compare two images of the Crab Nebula taken more than 40 years apart. By measuring the motion of some of the knots of glowing gas in the neubla, students will be able to determine the date of the supernova explosion that... (View More) set the Crab Nebula into motion. This is Activity 2 of the "Supernova Educator's Guide" developed by the XMM-Newton and GLAST E/PO programs. The guide features background information, assessment rubrics, student worksheets, extension and transfer activities, and alignment to national education standards. Note: In 2008, GLAST was renamed Fermi, for the physicist Enrico Fermi. (View Less)

In this activity, students use Newton's Laws of Motion, and the motions of the planets, to determine the mass of the sun. They then use the same techniques to determine the mass of a galaxy. In doing so, students convert among different units of... (View More) measure used in astronomy. This activity includes a student worksheet and background information for the teacher. It is activity 6d in the "Hidden Lives of Galaxies" information and activity booklet. (View Less)

In this activity, students will use a simulator of an orbiting X-ray observatory to observe a supernova remnant, the expanding gas from an exploded star. They will take X-ray spectral data, analyze them, and answer questions based on that data. This... (View More) resource consists of a manual and software for the Introductory Astronomy Lab Exercise, from CLEA (Contemporary Laboratory Experiments in Astronomy). The manual includes introductory activities for students, background information, an instructor's guide, a student handout, an answer key, a software user's guide, and a glossary. The student section of the activity starts on page 13. See Related & Supplemental Resources for a link to download the software. Note: the software is only available for Windows. (View Less)

In this activity, students use rulers to measure distances between hypothetical galaxies and then use these distances to calculate the velocities of the galaxies. This activity is part of the "Cosmic Questions" educator's guide that was developed to... (View More) support the Cosmic Questions exhibit. This activity can be in conjunction with, or independently of, the exhibit. (View Less)

In this activity, students examine the first line of evidence, galactic motion, for the notion of an expanding universe. By examining the spectrum of light from a galaxy, students can determine whether a galaxy is moving toward or away from us, and... (View More) how fast. Students will look at optical images of four galaxies, compare the emission spectra from these same four galaxies, and measure the wavelength of the red hydrogen line for each galaxy. This activity is part of the "Cosmic Questions" educator's guide developed to support the Cosmic Questions exhibit. This activity can be used in conjunction with, or independently of, the exhibit. (View Less)