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The Advanced Composition Explorer
The Advanced Composition Explorer was launched August 25, 1997 carrying six high-resolution spectrometers that measure the elemental, isotopic, and ionic charge-state composition of nuclei from H to
Voyager 1 Observes Low-Energy Galactic Cosmic Rays in a Region Depleted of Heliospheric Ions
Observations of energetic ions and electrons by Voyager 1 suggest that a sharp and distinct boundary was crossed five times over ∼30 days, indicating that Voyager 1 had not crossed the heliopause but had entered a region in the heliosphere that serves as a magnetic highway along which low-energy ions from inside stream away and galactic cosmic rays flow in from interstellar space.
The advanced composition explorer
The Advanced Composition Explorer (ACE) was recently selected as one of two new Explorer‐class missions to be developed for launch during the mid‐1990’s ACE will observe particles of solar,
Voyager 1 Explores the Termination Shock Region and the Heliosheath Beyond
The intensity of anomalous cosmic ray (ACR) helium did not peak at the shock, indicating that the ACR source is not in the shock region local to Voyager 1, and the intensities of ∼10–megaelectron volt electrons, ACRs, and galactic cosmic rays have steadily increased since late 2004.
Crossing the Termination Shock into the Heliosheath: Magnetic Fields
Magnetic fields measured by Voyager 1 show that the spacecraft crossed or was crossed by the termination shock on about 16 December 2004 at 94.0 astronomical units, and the cosmic ray intensity increased when B was relatively large in the heliosheath.
> 25 MeV Proton Events Observed by the High Energy Telescopes on the STEREO A and B Spacecraft and/or at Earth During the First ∼ Seven Years of the STEREO Mission
Using observations from the High Energy Telescopes (HETs) on the STEREO A and B spacecraft and similar observations from near-Earth spacecraft, we summarize the properties of more than 200 individual
An asymmetric solar wind termination shock
The intensity of 4–5 MeV protons accelerated by the shock near Voyager 2 was three times that observed concurrently by Voyager 1, indicating differences in the shock at the two locations.
Composition of Anomalous Cosmic Rays and Other Heliospheric Ions
Interstellar pickup ions accelerated by the termination shock of the solar wind dominate the anomalous cosmic-ray (ACR) intensities observed by the Voyager spacecraft in the outer heliosphere. Using
Measurement of the Secondary Radionuclides 10Be, 26Al, 36Cl, 54Mn, and 14C and Implications for the Galactic Cosmic-Ray Age
We report on abundance measurements of ^(10)Be, ^(26)Al, ^(36)Cl, and ^(54)Mn in the Galactic cosmic rays (GCRs) using the Cosmic-Ray Isotope Spectrometer (CRIS) instrument aboard the Advanced
Since 2012 August Voyager 1 has been observing the local interstellar energy spectra of Galactic cosmic-ray nuclei down to 3 MeV nuc-1 and electrons down to 2.7 MeV. The H and He spectra have the