Presented By Molly Nipper

1. IBEX (Interstellar Boundary Explorer) Presented By Molly Nipper http://www.dailymail.co.uk/sciencetech/article-1079003/NASA-launches-satellite-scan-solar-systems-outer-limits.html

2. What is IBEX? • IBEX- Interstellar Boundary Explorer. • A NASA-funded Small Explorer satellite mission to orbit Earth and map the boundary of the Solar System. • IBEX was launched on October 19, 2008. • Collects particles which stream inward toward Earth called Energetic Neutral Atoms (ENAs), particles with no charge that move very fast • Particles that are collected by IBEX allows us to study the entire edge of our Solar System all at once.

3. What defines the boundary of our Solar System? • Scientist use the interaction between the solar wind and the interstellar medium to define the boundary of our Solar System. http://www.nasa.gov/vision/universe/solarsystem/voyager_heliosphere.html

4. What is the Solar Wind? • The solar wind particles flow off the Sun’s corona. High temperatures from the corona cause particles to move extremely fast. • The solar wind streams off of the Sun in all directions at speeds of about 400 km/s (about 1 million miles per hour). • Due to particles moving extremely fast , the Sun’s gravity is not strong enough to hold them down , and they fly off, becoming part of the solar wind. XRT Full Sun (Synoptic). (Credit: Images courtesy of JAXA, NAOJ, PPARC and NASA.)

5. The solar wind continued… • The solar wind is a stream of charged particles, called plasma. • Plasma is similar to gas, but its particles have a different structure and charge. • Plasma is formed when a gas becomes extremely hot. This also cause the particles to have very high energy. • The energy causes the electrons to detach from the nuclei and this is when the gas becomes ionized . Plasma is an ionized gas. http://solarscience.msfc.nasa.gov/SolarWind.shtml

6. What is the interstellar medium? • The interstellar medium (ISM) is space between the stars. • It contains traces of gas and dust. • The ISM is mostly made of clouds of hydrogen and helium. http://www.space.com/php/multimedia/imagegallery/igviewer.php?imgid=3725&gid=272&index=0

7. What is IBEX’s mission? • IBEX will detect particles Energetic Neutral Atoms (ENA) traveling inward from the boundary toward our region of the Solar System. • This will allow IBEX to map the boundary of our Solar System from Earth’s point of view looking outward. • IBEX will travel to the edge of the protective “bubble” around the solar system called heliosphere, in the ISM around our Solar System.

8. What is a heliosphere? • The solar wind blows against this material and clears out a bubble-like region in this gas. • This bubble that surrounds the Sun and the Solar System is called the heliosphere. • The edge of this bubble is called the heliopause, which is the boundary of the Solar System.

9. An artist’s rendition of our heliosphere Image credit: Walt Feimer, NASA GSFC http://www.nasa.gov/multimedia/podcasting/IBEXBoundaries.html

10. How does IBEX collect these particles? • Using two sensors, called IBEX-Hi and IBEX-Lo, the spacecraft measures and counts the ENAs. It detects ENAs from 0.01 to 6 keV. • The sensors also detects the direction it came from. • IBEX spins once every 15 seconds, and moves around the Sun along with the earth once a year so that the sensors are exposed to each part of the heliosphere. • IBEX-Hi measures particles of higher energies in six energy bands. IBEX-Lo measures lower energy particles in eight energy bands. Images from: http://www.nasa.gov/mission_pages/ibex/index.html

11. IBEX first heliospheric results and sky maps Scientists can create maps of the boundary using this information. http://ibex.swri.edu/

12. What does the map show? • A range of ENA energies, using data collected over the course of six months. • There are 5 maps superimposed on this picture. • The map shows ENAs detected at five different energy levels from ~0.6-5.6 keV across the whole sky. • In each map: • Red=highest number of ENAs measured by the spacecraft. • Yellow and green = lower numbers of ENAs • Blue and purple = lowest number of ENAs.

13. ENAs may be significantly enhanced in highly localized regions at the interstellar boundary. ENA fine details in the ribbon. Credit: Southwest Research Institute

14. Bright ribbon on the map. • Large amount of ENAs showing up as a bright ribbon on the map. • The ribbon extends over a broad range of ecliptic latitudes and longitudes. • It is observed at energies from 0.2 to 6 kilo–electron volts. • The ribbon is a factor of 2 to 3 times higher than that of the more diffuse, globally distributed heliospheric ENA flux. • This ribbon was a surprise to the scientists and was not predicted by any existing models. • The scientists’ job now is to make new models based on these maps to figure out what is happening at the edge of a Solar System.

15. Hydrogen and oxygen atoms drifting in from the interstellar medium, outside the heliosphere. First observation of interstellar neutral Hydrogen and Oxygen. Credit: University of New Hampshire/Boston University

16. Neutral atoms discovered outside the heliosphere • IBEX has made the first direct observations of other neutral atoms—hydrogen and oxygen atoms drifting in from the interstellar medium, outside the heliosphere.

17. Why is IBEX’s mission important? • IBEX will be the first spacecraft to map the entire region of the Solar System boundary. • Mapping the heliopause will help scientists to determine what this protective boundary is like. • The heliopause protects our Solar System from cosmic rays. • Knowing more about the protective abilities of the heliopause will help us plan for future long-term space travel that is safer for humans.

18. What is in store for IBEX’s future? • IBEX’s primary mission will last for two years. • If the spacecraft is healthy in mid-2010, and if NASA’s budget permits, then the mission may be extended. • Scientists are eager to make several maps of the heliopause.

19. References • Angrum, Andrea. (2009, November 14). Voyager 2 Proves Solar System Is Squashed . Retrieved on November 14, 2009, from http://voyager.jpl.nasa.gov/news/voyager_squashed.html • Christian, Eric and McComas, Dave. (2008, July 30). IBEX: What Are Our Solar System's Boundaries. Retrieved on December 6, 2009 from http://www.nasa.gov/multimedia/podcasting/IBEXBoundaries.html • Fuselier et al., (2009, November 13). Width and variation of the ENA flux ribbon observed by the interstellar Boundary Explorer. Science, 326, 962-964. • Hathaway, David H. (2007, January 18). Solar wind. Retrieved on December 6, 2009 from http://solarscience.msfc.nasa.gov/SolarWind.shtml • McComas, Dave. (2009, October 15). IBEX : Interstellar Boundary Explorer. Retrieved on November 10, 2009, from http://ibex.swri.edu/ • McComas et al., (2009, November 13). Global observations of the interstellar interaction from the Interstellar Boundary Explorer (IBEX). Science, 326, 959-962.

20. References • Moebius et al., (2009, November 13). Direct obersvations of interstellar H, He, and O by the Interstellar Boundary Explorer. Science, 326, 969-971. • Schwadron et al., (2009, November 13). Comparison of Interstellar Boundary Explorer observations with 3-D Global Heliospheric Models. Science, 326, 966-968. • University College London (2009, November 22). Solar winds triggered by magnetic fields. ScienceDaily. Retrieved December 7, 2009, from http://www.sciencedaily.com­/releases/2009/11/091102112048.html