The methods of local interstellar medium investigation
Astro Space Centre, Lebedev Physical Institute, Russian Academy of Sciences, ul. Profsoyuznaya 84/32, Moscow, 117997, Russian Federation
The question of the Sun motion relative to the local interstellar medium (LISM) is examined. Results from Russian, US and French satellites and space probes on the observation of scattered solar radiation in hydrogen Lyman-alpha ($\lambda$ = 1215.7 Å) and helium ($\lambda$ = 584 Å) lines are presented. Data are briefly discussed on the direct registration inside the solar system of neutral helium atoms entering from LISM; as well as of helium pick up ions and of fast neutral hydrogen atoms. The fast neutral hydrogen atoms arise in the region of solar wind—LISM interaction.