Report: Voyager 1 has left solar system
NASA's venerable Voyager I spacecraft may have become the first man-made object to leave the solar system, an astronomer suggests.
But NASA isn't buying it, at least not yet.
Scientists have been anticipating this moment for years, but the boundary between the edge of the solar system and what's called interstellar space has been something of a moving target. Astronomers say it's the point where the stream of electrically changed particles from our sun, called the solar wind, peter out and the cosmic rays from distant exploding stars coming from other directions become the dominant form of radiation.
The distances are somewhat mind-boggling. Pluto is about 3.7 billion miles from the sun. Voyager is now about 17 billion miles away, where any signal it sends takes 17 hours to reach Earth.
For several years, the spacecraft, launched in 1977, has been crossing through the edge of the “heliosphere,” the bubble of charged solar particles created by the solar wind that shields our solar system from these distant galactic rays. The size of the heliosphere expands and contracts depending on the strength of the solar wind.
On Aug. 25, astronomers reported in the Geophysical Research Letters journal that galactic cosmic ray intensity suddenly doubled as measured by the spacecraft, indicating it had traveled beyond the protection of the solar wind. This boundary marks the edge of the sun's heliosphere.
“The cosmic ray intensity went up as you would expect if it exited the heliosphere,” said astronomer Bill Webber of New Mexico State University in Las Cruces, in a statement. The observation had been presented in December a scientific meeting but hadn't been accepted for publication into a scientific journal, until now.
But the scientists behind the Voyager mission are taking issue with the finding. “The Voyager team is aware of reports today that NASA's Voyager 1 has left the solar system,” said Caltech's Edward Stone, in a statement on the newly released study. “It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space. In December 2012, the Voyager science team reported that Voyager 1 is within a new region called ‘the magnetic highway' where energetic particles changed dramatically. A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space and that change of direction has not yet been observed.”
Further, a Voyager mission guest investigator, astrophysicist Merav Opher of Boston University, disputes the idea that the spacecraft has left the solar system.
“The magnetic field it measures is one completely dominated by the sun's influence,” she says.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.
- Suspect in killings of wealthy D.C. family arrested
- Romney throws hat into different ring to fight Holyfield
- 5 big banks plead guilty to currency manipulation
- Senators push for full funding for Amtrak
- Ex-Va. lawmaker plans to wed teen in sex scandal
- Boston doles out justice to terrorist Tsarnaev in form of death penalty
- Former bin Laden aide sentenced to life
- 1 critical, 3 hospitalized after fatal Marine Corps crash
- Capitol Police get training to remember to retain guns after using bathroom
- Legislators continue to slow trade proposal
- House OKs 7th straight year without pay raise for Congress