Mysterious 'energy ribbon' at solar system's edge baffles scientists

First spotted by a NASA spacecraft, a bizarre ribbon of high-energy particles could help unlock secrets about the boundary between our solar system and interstellar space. 

|
NASA/IBEX/UNH
A model of the interstellar magnetic fields – which would otherwise be straight – warping around the outside of our heliosphere, based on data from NASA's Interstellar Boundary Explorer. The red arrow shows the direction in which the solar system moves through the galaxy.

A strange ribbon of energy and particles at the edge of the solar system first spotted by a NASA spacecraft appears to serve as a sort of "roadmap in the sky" for the interstellar magnetic field, scientists say.

By comparing ground-based studies and in-space observations of solar system's mysterious energy ribbon, which was first discovered by NASA's Interstellar Boundary Explorer (IBEX) in 2009, scientists are learning more details about the conditions at the solar system's edge. The study also sheds light into the sun's environment protects the solar system from high-energy cosmic rays. [Photos and Images from NASA's IBEX Spacecraft]

"What I always have been trying to do was to establish a clear connection between the very high-energy cosmic rays we're seeing [from the ground] and what IBEX is seeing," study leader Nathan Schwadron, a physicist at the University of New Hampshire, told Space.com.

Previously, maps from ground-based observatories showed researchers that clusters of cosmic rays — extremely high-energy particles that originate from supernovas — are correlated with the IBEX ribbon. The ribbon is roughly perpendicular to the interstellar magnetic field while cosmic rays stream, on average, along the interstellar magnetic field. (The particles themselves are created from interactions between the solar wind and interstellar matter.)

In the longer term, Schwadron said work like this will help scientists better understand more about the boundary between our solar system and interstellar space. This is a region that only one mission — NASA's Voyager 1 spacecraft — has reached so far, and scientists know little about what that environment is like.

Travelling through the transition zone

The sun's sphere of influence in the solar system is known as the heliosphere. The sun's "solar wind" of high-energy particles flows within the heliosphere and pushes back against high-energy cosmic rays originating in interstellar space. The transition zone between these two regions is called the heliosheath.

Here's where a mystery arises: Voyager 1's measurements of the magnetic field from the edge of interstellar space show a starkly different direction of the magnetic field inferred in the IBEX ribbon, Schwadron said.

"At that point, you say to yourself what’s wrong? What could possibly be the issue? It seems like we now have good independent confirmation that the IBEX ribbon is ordered by the interstellar magnetic field, and we know that Voyager 1 takes fairly good measurements," Schwadron said.

The few studies examining this issue, showing little consensus. An October paper co-authored by Schwadron in Astrophysical Journal Letters argued that Voyager 1 could be measuring interstellar plasma coming in through magnetic field lines, but may still be in the heliosheath itself. This stands in contrast to findings from NASA and other science groups saying Voyager 1 is definitively in interstellar space.

The researchers noted that Voyager 1 is picking up its information "at a specific time and place", but IBEX's data is collected and averaged across vast distances, so that could also lead to discrepancies.

"What is really missing here is our understanding of the physics," Schwadron said, adding that reconnection between magnetic field lines could be an example of something that changes the conditions of the boundary region.

The research was published today (Feb. 13) in the journal Science Express and includes participation from several United States research institutions.

Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. We're also on Facebook and Google+. Original article on Space.com.

Copyright 2014 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Mysterious 'energy ribbon' at solar system's edge baffles scientists
Read this article in
https://www.csmonitor.com/Science/2014/0214/Mysterious-energy-ribbon-at-solar-system-s-edge-baffles-scientists
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe