The Voyager Journey to the Giant Planets and Interstellar Space E. C. STONE HST- Orion 8/11/11
Gary Flandro 1965
Plasma Science (Voyager 2) J.D. Richardson, J. W. Belcher, L. F. Burlaga, A.J. Lazarus, R. McNutt, E.C. Sittler, Jr., C. Wang Low-Energy Charged Particles S.M. Krimigis, T.P. Armstrong, R.B. Decker, G. Gloeckler, D.C. Hamilton, L.J. Lanzerotti, B.H. Mauk, R. McNutt, E.C. Roelof Cosmic Ray Subsystem E.C. Stone, A.C. Cummings, N. Lal, F.B. McDonald, W.R. Webber Magnetometer N.F. Ness, L.F. Burlaga, J.P. Connerney, R.P. Lepping, C. Smith, F.M. Neubauer Plasma Wave Subsystem D.A. Gurnett, W.S. Kurth
Topics The Giant Outer Planets The Heliosphere Approaching the Boundary The Local Interstellar Medium
Voyager- Jupiter
Io is Volcanically Active Sheds 1 ton/second of Sulfur and Oxygen Voyager- Io
Voyager- Io
80 km Galileo Mission
Voyager- Enceladus
Europa (Galileo)
Voyager- Saturn
Enceladus
Enceladus (Cassini)
Voyager- Titan
ESA/Huygens Probe
Titan (Cassini)
Voyager- Uranus
Voyager- Uranus
Voyager- Miranda
Voyager- Neptune
Voyager- Triton
Uranus from Keck Observatory
HUBBLE SPACE TELESCOPE
HUBBLE SPACE TELESCOPE KECK Courtesy: L. Sromovsky
Voyager
Keck Voyager
SOHO
An Interstellar Wind Will Create a Comet-like Heliosphere Interstellar Wind Parker 1961
Muller, Zank Interstellar Wind
HST- Orion
WISE- Zeta Ophiuchi
The Heliosphere in a Kitchen Sink Solar Wind - radial flow Interstellar Space Termination Shock Heliosheath- flow turn toward drain Heliopause- boundary of heliospheric bubble 4/30/2010-3
V2 V1
Side view of the heliosphere TS What s in the heliosheath? Hot (100,000 K), fast (~100 km/s), wind The speed in the outward direction decreases as the flow turns to flow down the tail (green flow arrows) Opher et al. Sun is ~1500 times larger than scale
Acceleration of interstellar pickup ions at the termination shock (Fisk et al., 1974; Pesses, Jokipii, & Eichler, 1981) 40
Evolution of energy spectra of H, He, and O at V1 TSP TSP ACR ACR GCR ACR GCR GCR Just after TSX Only low energy TSPs accelerated at shock where V1 crossed Higher energy ACRs observed at 1 AU are accelerated elsewhere and have been increasing away from shock 41
TSP 113 AU TSP V2 V1 TSPs steady for 3 years, but decreasing since 2010.3 Diffusive leakage across nearby heliopause?
N -R T
V1 orientation with Rigel Kentaurus lockstar N T
V1: 53-85 kev 2007/345 V Decker et al.
-17 km/s Decker et al. SH23D-02
The Heliosheath Solar Wind Has Turned the Corner Since mid-2010, the radial wind speed has been essentially zero The average Tangential (longitudinal) speed hasn t changed The Normal speed (latitudinal) is unmeasured Decker et al. SH23D-02
Krimigis et al. 2011
Transition layer - close to or at the heliopause? Krimigis et al. 2011
Side view of the heliosphere R N TS The speed in the outward direction decreases as the flow turns in the N direction to flow down the tail (green flow arrows) Opher et al. Sun is ~1500 times larger than scale 7/20/2011-4
N 10 revolutions about R axis CCW as viewed from Sun 2000 seconds per revolution. Intensity of low energy ions normal to roll axis measured every 48 sec -R T
3.1±0.2% 2.3±0.2% N N 59±4 V -T 62±5 -T
0.9±0.2% 0.4±0.2% N N 44±13 -T -T
N N 2008/071 2009/069 59±4 V 62±5 -T -T N N 44±13 2010/218 2010/309 -T -T Flow is not turning northward, is just slowing V1 is in stagnation region
Interstellar B Flat current sheet Flows deflected to parallel the blunt heliopause Radial component except near stagnation point V1 north of stagnation point Dynamical effect? Opher et al.
V1 at 117.8 AU in Boundary Region Inner Edge 113 AU Radial extent is unknown V1 moves outward 1 billion km every 2 years Outer Edge- any day or several years 7/20/2011-6
What Is Outside In Local Interstellar Space?? H Termination Shock Particles Anomalous Cosmic Rays He O Sources inside heliosphere Intensities lower outside Low Energy Galactic Cosmic Rays C Nearby OB association source Intensity higher outside? 57
~20 km/s 26 km/s Frisch & Huff
B ~20 km/s 60º 26 km/s Frisch & Huff Local interstellar magnetic field associated with the shell of the Scorpius Centaurus superbubble P. Frisch 2009
Side view of the heliosphere TS Local Interstellar Medium Cooler (7000 K), slower (~26 km/s), denser interstellar wind from explosion of giant super novae 5 to 10 M years ago Interstellar ions deflected around heliosphere Interstellar magnetic field (black arrows) ~4 µg and inclined to ecliptic plane Opher et al. Opher et al. Sun is ~1500 times larger than scale Electrical power beyond 2020 V1: 150 AU (23 billion km) V2: 125 AU (19 billion km)
The Journey to Interstellar Space Continues