heliopause


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Related to heliopause: termination shock, Bow shock

heliopause

(hee -lee-oh-pawz) See heliosphere.

heliopause

[′hē·lē·ə‚pȯz]
(astronomy)
A shock front about 50 astronomical units from the sun, where the thermal pressure of the interstellar gas which surrounds the solar system overcomes the pressure of the solar wind, which is mostly ram pressure due to its high-velocity flow.
References in periodicals archive ?
This means that while Voyager 1 did cross the heliopause in 2012, it is still traveling through this "muddied" magnetic field region and won't reach the "pristine" region of interstellar space until at least 2025.
Notes Schwadron, who serves as the lead scientist for the IBEX Science Operations Center at UNH, "Our analysis confirms two things for the first time: that the center of the IBEX ribbon is the direction of the interstellar magnetic field and, secondly, that Voyager 1 is now beyond the heliopause.
Scientists believe Voyager 1 has not yet crossed the heliopause into interstellar space.
From the speed of the clouds and the time it took them to reach the heliopause, Gurnett's team calculated the distance to the edge.
Intriguingly, notes Frisch, the hydrogen atoms observed at the heliopause, along with other atoms, molecules, and ions-all refugees from interstellar space-invade the solar system and dominate much of interplanetary space.
Eventually, Gurnett suggests, the bulkier solar wind reached the heliopause.
Electronic interference may make signals even harder to read when and if the craft reach the far side of the heliopause.
But wherever that shock wave lies, just outside it will almost surely be the heliopause (SN:10/7/89, p.
Many scientists believe that such a shock wave exists on a vastly larger scale in a region called the heliopause, where a similar "wind" from other stars meets the distant limits of the sun's own magnetic field, or magnetosphere.
No one knows just how far away the heliopause lies, but officials estimate that Voyager's radio messages may remain detectable from Earth until about the year 2020.
Another envisioned mission is the Interstallar Probe, to venture beyond the heliopause -- the "edge" of the sun's influence -- to study the interstellar medium.
It could study the heliopause, the ultimate outer limit of the solar system, the boundary where the solar wind peters out and the sun ceases to dominate the physics of space.