[FPSPACE] Interstellar Dust Inside and Outside the Heliosphere

[LARRY KLAES]

Interstellar Dust Inside and Outside the Heliosphere

Authors: Harald Krueger, Eberhard Gruen

(Submitted on 26 Feb 2008)

Abstract: In the early 1990s, after its Jupiter flyby, the Ulysses 
spacecraft identified interstellar dust in the solar system. Since then the 
in-situ dust detector on board Ulysses continuously monitored interstellar 
grains with masses up to 10e-13 kg, penetrating deep into the solar system. 
While Ulysses measured the interstellar dust stream at high ecliptic 
latitudes between 3 and 5 AU, interstellar impactors were also measured with 
the in-situ dust detectors on board Cassini, Galileo and Helios, covering a 
heliocentric distance range between 0.3 and 3 AU in the ecliptic plane.

The interstellar dust stream in the inner solar system is altered by the 
solar radiation pressure force, gravitational focussing and interaction of 
charged grains with the time varying interplanetary magnetic field. The 
grains act as tracers of the physical conditions in the local interstellar 
cloud (LIC). Our in-situ measurements imply the existence of a population of 
'big' interstellar grains (up to 10e-13 kg) and a gas-to-dust-mass ratio in 
the LIC which is a factor of greater than 2 larger than the one derived from 
astronomical observations, indicating a concentration of interstellar dust 
in the very local interstellar medium.

Until 2004, the interstellar dust flow direction measured by Ulysses was 
close to the mean apex of the Sun's motion through the LIC, while in 2005, 
the data showed a 30 deg shift, the reason of which is presently unknown. We 
review the results from spacecraft-based in-situ interstellar dust 
measurements in the solar system and their implications for the physical and 
chemical state of the LIC.

Comments:  10 pages, 2 b/w figures, 1 colour figure; submitted to Space 
Science Reviews

Subjects:  Astrophysics (astro-ph)

Cite as:  arXiv:0802.3787v1 [astro-ph]

Submission history

From: Harald Krueger [view email]

[v1] Tue, 26 Feb 2008 11:00:16 GMT (225kb,D)

http://arxiv.org/abs/0802.3787