This document discusses Voyager 1 and 2's journey beyond the outer planets to reach interstellar space and the edge of the solar system. It summarizes the Voyagers' missions, key findings so far indicating Voyager 1 reached interstellar space in 2012, and what further observations and understanding is expected going forward from continued Voyager measurements at the solar system boundary. The speaker thanks the audience for their attention and invites questions.

1. “Are we there yet?”
Thomas P Armstrong
July 27, 2013
Galaxy Forum
The Kansas Cosmosphere
Sponsored by
Ad Astra Kansas Foundation

2. The BIG questions
1. Where does the solar system end and the
galaxy begin?
2. How will we know when we get there?
3. What new science and human understanding
can be expected from “getting there”?

3. Voyager Launch from
Cape Kennedy in 1977
• Voyager 1 flew
by Jupiter in
March
1979, followed
by Voyager 2 in
August.
 V2 flew by
Saturn in
August
1980, followed
by V1 in
October.

4. Voyager 1 and 2 Travelogue

5. History
• After its Saturn flyby, Voyager 1 was targeted
to follow a trajectory to reach the outer
heliosphere “quickly”.
• After its Saturn flyby, Voyager 2 was targeted
to fly by Uranus in 1986 and Neptune in 1989.
• After the planetary missions were
complete, both spacecraft were
reprogrammed to continue recording radio
waves, plasma, and radiation arriving at the
spacecraft.

6. Heliospheric Regions and Boundaries
holoscience.com

8. Answers (as of today!)
• The “cliff” last September was probably the
“edge”
• When the low energy (heliospheric—
i.e., made by the Sun) radiation went
away, that was a very strong indication of the
“edge”
• When the high energy radiation (galactic
cosmic rays) increased, that was a very strong
indication of the “edge”

9. “Embargoed”
• Awaiting publication are results from Voyager
1 Plasma Wave System (local radio receiver)
that tend to corroborate the “cliff” hypothesis.

10. Yet to be explained
• The magnetic field at Voyager 1 is much
stronger than has been expected from
astronomical observations of the polarization
of starlight, and its direction appears to be
controlled by the orientation of the Sun’s axis!

11. Important Links
• http://voyager.jpl.nasa.gov/
• http://sd-www.jhuapl.edu/VOYAGER/
• http://www.ftecs.com/Related-
sites.html#voyager
• http://bbc.in/19i35Pw
• http://saturn.jpl.nasa.gov/education/saturnob
servation/viewingsaturn/

12. What next?
• Voyager 1 observations will continue and
develop more certainty.
• Voyager 2 observations will continue and a
“cliff” crossing is expected one of these years.
• More modeling and analysis of the details of
the composition and spectra of galactic
radiation will continue, seeking clues from its
elemental and spectral composition.

13. Thank you for your attention.
Questions?

17. Earth viewed from Cassini at Saturn
• Carolyn Porco the Cassini Imaging Team leader
arranged to have Earth’s family portrait done
on July 19. Wide angle and narrow angle
views follow