Galaxy Evolution Explorer: Studying Star Formation in the Universe

1. TABLE OF CONTENTS Table of Contents • Mission Overview • Timeline • Scientific Objectives • Links Image from NASA Artist’s rendition of GALEX

2. MISSION OVERVIEW • The Galaxy Evolution Explorer is an orbiting space telescope that makes observations at ultraviolet wavelengths to measure the history of star formation in the universe 80 percent of the way back to the Big Bang. Since scientists believe the universe is about 13 billion years old, the mission will study galaxies and stars across about 10 billion years of cosmic history. Image from NASA GALEX image of the Southern Pinwheel glaxy. Back to Table of Contents

3. TIMELINE • GALEX launched April 28th, 2003 aboard a Pegasus rocket. • Although originally planned as a 29-month mission, the NASA Senior Review Panel in 2006 recommended that the mission lifetime be extended. Image from NASA A cartwheel galaxy imaged by GALEX. Back to Table of Contents

4. SCIENTIFIC OBJECTIVES • The spacecraft's mission is to observe hundreds of thousands of galaxies, with the goal of determining how far away each galaxy is from Earth and how fast stars are forming in each galaxy. A galaxy’s ultraviolet brightness tells us how fast its stars are forming. Andromeda, the Galaxy Next Door

5. SCIENTIFIC OBJECTIVES • Mission scientists will be trying to find stars that have recently formed, so they will be looking for stars whose appearance reveals them to be young. These are the most massive stars, which are so hot they shine in ultraviolet wavelengths. Gravitational Dance: NGC 1512 and NGC 1510 Back to Table of Contents

6. LINKS • http://www.galex.caltech.edu/index.html • http://www.nasa.gov/centers/jpl/missions/galex.html Image from NASA Artist’s rendition of GALEX Back to Table of Contents