ScienceJuly 20, 2026
heliosphere
ˈhiːliəsfɪər
Definition
The vast, bubble-like region of space dominated by the sun, defined by the reach of the solar wind and the magnetic fields emanating from the sun.
Etymology
The term is derived from the Greek 'helios' (sun) and 'sphaira' (globe or ball). It was constructed in the 20th century to describe the specific extent of solar influence in the vacuum of space.
In the news
In this article, the heliosphere is described as a protective boundary for the solar system that extends well beyond Pluto. It highlights the current scientific debate regarding the true, irregular shape of this bubble as it moves through interstellar space.
Science word of the day: Heliosphere
Read the full article ↗Live Science