Category: Books Online
AC1C. Stay Current—Cosmic Cataclysms
Staying current for Chapter 1 { A Changing Cosmos Contents } SEE ALSO: Life & Climate Chapter 9, What Happened to the Dinosaurs? and General Astronomy Resources Articles from 2002 – present 2024-01-31. Planets around dead stars offer glimpse of the Solar System’s future—after the Sun swallows us up. [https://www.science.org/content/article/planets-around-dead-stars-offer-glimpse-solar-system-s-future-after-sun-swallows-us] By JONATHAN O’CALLAGHAN, Science. Excerpt: In […]
AC9.4. Counting Galaxies
Investigation AC9.4 { A Changing Cosmos Contents } [by Rich Lohman] Materials: How many galaxies are there in the Universe? You may have heard some numbers. If you have (or even if you haven’t) write down a number right here that you think is the number of galaxies in the Universe. My guess or recollection […]
AC9.3. Hubble’s Law
{ A Changing Cosmos Contents } { All GSS Books } What’s the evidence that our Universe is expanding, contracting, or staying the same? Materials Worksheet “Spectra of Fast-Moving Galaxies” Worksheet “Hubble’s Law” The line spectrum of hydrogen, the most common element in the Universe, has characteristic lines (wavelengths or frequencies) in the regions red, […]
AC9. The Cosmos Begins…and Ends?
Chapter 9 { A Changing Cosmos Contents } Where did the Universe come from? How did it start? What were things like way back when? Will the Universe end and if so, how? And when? Contemplating such questions is a realm of study called cosmology. Getting at answers can take us to the very largest […]
AC8.1. Exoplanet Transits
Investigation 8.1 { A Changing Cosmos Contents } Who would have guessed that from simply measuring brightness changes in a star, we could find not only whether the star has a planet, but a host of interesting properties of that planet as well. Even whether or not the planet might be inhabitable by life forms! […]
AC8. Search for Habitable Planets
Chapter 8 { A Changing Cosmos Contents } We know of one habitable planet in the Universe, habitable meaning suitable for supporting life such as that we are familiar with. That one habitable planet is our own: Earth. For centuries, some people have speculated that there may be many many such planets in other planet-star […]
AC7.2. Asteroid Search
{ A Changing Cosmos Contents } { All GSS Books } In Chapter 1, we saw how asteroids can be major threats to the well being of life on Earth. You can find out more about the NASA efforts concerning near Earth asteroids at the NASA Center for Near Earth Object Studies: https://cneos.jpl.nasa.gov/ The Hands-On Universe (HOU) […]
AC7.1. Tracking Jupiter’s Moons
Investigation AC7.1 { A Changing Cosmos Contents } Galileo discovered the four largest moons of Jupiter in 1610, and they are often referred to as the Galilean Moons. He was using a simple telescope and a keen mind. He noticed that Jupiter and these four dimmer lights, which he assumed were stars, were stretched out […]
AC7. Planet-Star Systems
Chapter 7 { A Changing Cosmos Contents } We wonder “Where did we come from, in the big scheme of things?” That leads to questions of how our planet began, which in turn leads to the question, “Where did our Solar System come from?” and “Where did the Universe come from?” That last question will […]
AC6.1. Finding Supernovae
Investigation AC6.1 { A Changing Cosmos Contents } Here are a series of exercises on finding supernovae, starting with simple specially prepared images and progressing to real life image analyses. Materials I. Comparing Images By Subtracting Our first exercise uses two images for which Aligning, Subtracting Sky Background, and Normalizing Brightness are not necessary. We […]