AGU: Voyager 1 has left the solar system, sudden changes in cosmic rays indicate
Thirty-five years after its launch, Voyager 1 appears to have travelled beyond the influence of the Sun and exited the heliosphere, according to a new study appearing online today. The heliosphere is a region of space dominated by the Sun and its wind of energetic particles, and which is thought to be enclosed, bubble-like, in the surrounding interstellar medium of gas and dust that pervades the Milky Way galaxy.
On August 25, 2012, NASA's Voyager 1 spacecraft measured drastic changes in radiation levels, more than 11 billion miles from the Sun. Anomalous cosmic rays, which are cosmic rays trapped in the outer heliosphere, all but vanished, dropping to less than 1 percent of previous amounts. At the same time, galactic cosmic rays -- cosmic radiation from outside of the solar system -- spiked to levels not seen since Voyager's launch, with intensities as much as twice previous levels.
The findings have been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
"Within just a few days, the heliospheric intensity of trapped radiation decreased, and the cosmic ray intensity went up as you would expect if it exited the heliosphere," said Bill Webber, professor emeritus of astronomy at New Mexico State University in Las Cruces. He calls this transition boundary the "heliocliff."
In the GRL article, the authors state: "It appears that [Voyager 1] has exited the main solar modulation region, revealing [hydrogen] and [helium] spectra characteristic of those to be expected in the local interstellar medium."
However, Webber notes, scientists are continuing to debate whether Voyager 1 has reached interstellar space or entered a separate, undefined region beyond the solar system.
"It's outside the normal heliosphere, I would say that," Webber said. "We're in a new region. And everything we're measuring is different and exciting."
The work was funded by NASA's Jet Propulsion Laboratory in Pasadena, Calif.
Source: American Geophysical Union
- So, has Voyager 1 left the Solar System? Scientists face offfrom News @ NatureFri, 22 Mar 2013, 15:30:32 EDT
- So, has Voyager 1 left the Solar System? Scientists face offfrom News @ NatureThu, 21 Mar 2013, 14:01:29 EDT
- Voyager 1 space probe reaches outer fringe of solar systemfrom Reuters:ScienceThu, 21 Mar 2013, 13:30:15 EDT
- Why Voyager 1's Solar System Exit Is So Hard to Predictfrom Live ScienceThu, 21 Mar 2013, 10:30:26 EDT
- Why Voyager 1's Solar System Exit Is So Hard to Predictfrom Space.comThu, 21 Mar 2013, 8:30:29 EDT
- Voyager 1 space probe enters 'new realm' – videofrom The Guardian - ScienceThu, 21 Mar 2013, 7:30:33 EDT
- Voyager 1 has left the solar system — almostfrom LA Times - ScienceWed, 20 Mar 2013, 23:30:22 EDT
- NASA’s Voyager 1 Not Yet Out of the Solar Systemfrom NY Times ScienceWed, 20 Mar 2013, 18:10:05 EDT
- NASA denies report that Voyager left solar systemfrom PhysorgWed, 20 Mar 2013, 17:31:26 EDT
- NASA's Voyager 1 probe may have left solar system: studyfrom CBSNews - ScienceWed, 20 Mar 2013, 17:30:24 EDT
- Voyager 1 space probe reaches outer fringe of solar systemfrom Reuters:ScienceWed, 20 Mar 2013, 16:20:17 EDT
- Voyager 1 at edge of our solar systemfrom UPIWed, 20 Mar 2013, 16:00:44 EDT
- Voyager 1 has left the solar systemfrom CBC: Technology & ScienceWed, 20 Mar 2013, 16:00:21 EDT
- Voyager 1 probe boldly goes, and goes – but is still in the solar system, says Nasafrom The Guardian - ScienceWed, 20 Mar 2013, 15:30:33 EDT
- ScienceShot: Has Voyager 1 Left the Solar System?from Science NOWWed, 20 Mar 2013, 15:10:08 EDT
- Voyager 1 has entered a new region of space, sudden changes in cosmic rays indicatefrom Science BlogWed, 20 Mar 2013, 15:00:20 EDT
- NASA Voyager Status Update on Voyager 1 Locationfrom NASA Jet Propulsion LaboratoryWed, 20 Mar 2013, 14:32:08 EDT
- Has Voyager 1 Left The Solar System? Cosmic Rays Say Yesfrom Scientific BloggingWed, 20 Mar 2013, 14:01:18 EDT
- Voyager 1 has entered a new region of space, sudden changes in cosmic rays indicatefrom Science DailyWed, 20 Mar 2013, 14:00:28 EDT
- Voyager 1 has left the solar system, sudden changes in cosmic rays indicatefrom PhysorgWed, 20 Mar 2013, 13:31:03 EDT
- NASA's Voyager 1 Probe Has Left Solar System: Studyfrom Space.comWed, 20 Mar 2013, 13:00:37 EDT
- Voyager craft exits the Solar Systemfrom BBC News: Science & NatureWed, 20 Mar 2013, 12:31:17 EDT
Latest Science NewsletterGet the latest and most popular science news articles of the week in your Inbox! It's free!
Check out our next project, Biology.Net
From other science news sites
Popular science news articles
- New research sees zebrafish earn their stripes in the fight against muscular dystrophy
- Climbing plants disturb carbon storage in tropical forests
- Measurements of dinosaur body temperatures shed new light on 150-year debate
- UF researchers learn how to keep pathogens, pests from traveling with grain
- RNA editing technique treats severe form of muscular dystrophy
- The reason why middle class people are more likely to play music, paint and act revealed
- Arctic mosquitoes thriving under climate change, Dartmouth study finds
- 'Tree of life' for 2.3 million species released
- Arctic sea ice summertime minimum is fourth lowest on record
- Sierra Nevada snowpack lowest in five centuries