Archive

Posts Tagged ‘Interstellar’

NASA Voyager: ‘Tsunami Wave’ Still Flies Through Interstellar Space

December 16, 2014 Leave a comment

Artist's concept. Image credit: NASA/JPL-Caltech

Artist’s concept. Image credit: NASA/JPL-Caltech

• The Voyager 1 spacecraft has experienced three shock waves

• The most recent shock wave, first observed in February 2014, still appears to be going on

• One wave, previously reported, helped researchers determine that Voyager 1 had entered interstellar space

The “tsunami wave” that NASA’s Voyager 1 spacecraft began experiencing earlier this year is still propagating outward, according to new results. It is the longest-lasting shock wave that researchers have seen in interstellar space.

“Most people would have thought the interstellar medium would have been smooth and quiet. But these shock waves seem to be more common than we thought,” said Don Gurnett, professor of physics at the University of Iowa in Iowa City. Gurnett presented the new data Monday, Dec. 15 at the American Geophysical Union meeting in San Francisco.

Link To Full Story And Video

Advertisements

New Milky Way Maps Help Solve Stubborn Interstellar Material Mystery

August 14, 2014 Leave a comment

An international team of sky scholars, including a key researcher from Johns Hopkins, has produced new maps of the material located between the stars in the Milky Way. The results should move astronomers closer to cracking a stardust puzzle that has vexed them for nearly a century.

The maps and an accompanying journal article appear in the Aug. 15 issue of the journal Science. The researchers say their work demonstrates a new way of uncovering the location and eventually the composition of the interstellar medium—the material found in the vast expanse between star systems within a galaxy.

This material includes dust and gas composed of atoms and molecules that are left behind when a star dies. The material also supplies the building blocks for new stars and planets.

“There’s an old saying that ‘We are all stardust,’ since all chemical elements heavier than helium are produced in stars,” said Rosemary Wyse, a Johns Hopkins professor of physics and astronomy who played a prominent role in the research and helped shape the Science paper. “But we still don’t know why stars form where they do. This study is giving us new clues about the interstellar medium out of which the stars form.”

Link To Full Story

Stardust Discovers Potential Interstellar Space Particles

August 14, 2014 Leave a comment

Seven rare, microscopic interstellar dust particles that date to the beginnings of the solar system are among the samples collected by scientists who have been studying the payload from NASA’s Stardust spacecraft since its return to Earth in 2006. If confirmed, these particles would be the first samples of contemporary interstellar dust.

A team of scientists has been combing through the spacecraft’s aerogel and aluminum foil dust collectors since Stardust returned in 2006.The seven particles probably came from outside our solar system, perhaps created in a supernova explosion millions of years ago and altered by exposure to the extreme space environment. The particles would be the first confirmed samples of contemporary interstellar dust.

The research report appears in the Aug. 15 issue of the journal Science. Twelve other papers about the particles will appear next week in the journal Meteoritics & Planetary Science.

“These are the most challenging objects we will ever have in the lab for study, and it is a triumph that we have made as much progress in their analysis as we have,” said Michael Zolensky, curator of the Stardust laboratory at NASA’s Johnson Space Center in Houston and coauthor of the Science paper.

Link To Full Story
Link To Another Story

NASA’s Voyager 1 Reaches Interstellar Space

September 19, 2013 Leave a comment

NASA’s Voyager 1 spacecraft officially is the first human-made object to venture into interstellar space. The 36-year-old probe is about 12 billion miles (19 billion kilometers) from our sun.

New and unexpected data indicate Voyager 1 has been traveling for about one year through the plasma, or ionized gas, present in the space between the stars. Voyager is in a transitional region immediately outside the solar bubble, where some effects from our sun are still evident. A report on the analysis of these new data, an effort led by Don Gurnett and the plasma wave science team at the University of Iowa, Iowa City, is published this week in the journal Science.

“The crossing is like Voyager leaving the hot, million-degree atmosphere of the sun and entering into a region dominated by the ‘cold,’ 5,000-degree atmosphere of the galaxy,” says APL’s Stamatios (Tom) Krimigis, principal investigator for Voyager’s Low-Energy Charged Particle (LECP) instrument. “It’s like the first time a satellite [Sputnik] went beyond Earth’s atmosphere to an altitude of some 600 miles; Voyager is now leaving the solar bubble at an altitude of 11.3 billion miles. It’s another historic milestone.”

Link To Full Story.

IBEX Spacecraft Measures Changes In The Direction Of Interstellar Winds Buffeting Our Solar System

September 6, 2013 Leave a comment

Data from NASA’s Interstellar Boundary Explorer (IBEX) spacecraft reveal that neutral interstellar atoms are flowing into the solar system from a different direction than previously observed.

Interstellar atoms flow past the Earth as the solar system passes through the surrounding interstellar cloud at 23 kilometers per second (50,000 miles per hour). The latest IBEX measurements of the interstellar wind direction were discovered to differ from those made by the Ulysses spacecraft in the 1990s. That difference led the IBEX team to compare the IBEX measurements to data gathered by 11 spacecraft between 1972 and 2011. Statistical testing of the Earth-orbiting and interplanetary spacecraft data showed that, over the past 40 years, the longitude of the interstellar helium wind has changed by 6.8 ± 2.4 degrees.

“We concluded it’s highly likely that the direction of the interstellar wind has changed over the past 40 years. It’s also highly unlikely that the direction of the interstellar helium wind has remained constant,” says Dr. Priscilla Frisch, lead author of the study and a senior scientist in the Department of Astronomy and Astrophysics at the University of Chicago.

Full Story: http://www.swri.org/9what/releases/2013/ibex-wind.htm#.UilbyiywUV0

NASA’s Voyager 1 Explores Final Frontier Of Our ‘Solar Bubble’

July 2, 2013 1 comment

Artist's concept. Image Credit: NASA/JPL-Caltech

Artist’s concept. Image Credit: NASA/JPL-Caltech

Data from Voyager 1, now more than 11 billion miles (18 billion kilometers) from the sun, suggest the spacecraft is closer to becoming the first human-made object to reach interstellar space.

Scientists have seen two of the three signs of interstellar arrival they expected to see: charged particles disappearing as they zoom out along the solar magnetic field, and cosmic rays from far outside zooming in. Scientists have not yet seen the third sign, an abrupt change in the direction of the magnetic field, which would indicate the presence of the interstellar magnetic field.

“This strange, last region before interstellar space is coming into focus, thanks to Voyager 1, humankind’s most distant scout,” said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. “If you looked at the cosmic ray and energetic particle data in isolation, you might think Voyager had reached interstellar space, but the team feels Voyager 1 has not yet gotten there because we are still within the domain of the sun’s magnetic field.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-209
Also: http://www.jhuapl.edu/newscenter/pressreleases/2013/130627.asp

New “Retention Model” Explains Enigmatic Ribbon At Edge Of Solar System

February 13, 2013 Leave a comment

Since its October 2008 launch, NASA’s Interstellar Boundary Explorer (IBEX) has provided images of the invisible interactions between our home in the galaxy and interstellar space. Particles emanating from this boundary produce a striking, narrow ribbon, which had yet to be explained despite more than a dozen possible theories. In a new “retention model,” researchers from the University of New Hampshire and Southwest Research Institute suggest that charged particles trapped in this region create the ribbon as they escape as neutral atoms.

The Sun continually sends out a solar wind of charged particles or ions traveling in all directions at supersonic speeds. IBEX cameras measure energetic neutral atoms (ENAs) that form when charged particles become neutralized.

As solar wind ENAs leave the solar system, the majority move out in various directions, never to re-enter. However, some ENAs leave the solar system and impact other neutral atoms, becoming charges particles again. These newly formed pickup ions begin to gyrate around the local interstellar magnetic field just outside the solar system. In the regions where the magnetic field is perpendicular to their initial motion, they scatter rapidly and pile up. From those regions, some of those particles return to the solar system as secondary ENAs — ENAs that leave the solar system and become charged and then re-neutralized, only to travel back into the solar system as ENAs a second time.

“The syrup you pour on a pancake piles up before slowly oozing out to the sides,” says Dr. David McComas, IBEX principal investigator and assistant vice president of the SwRI Space Science and Engineering Division. “The secondary ENAs coming into the solar system after having been temporarily trapped in a region just outside the solar system do the same thing. As they pile up and get trapped or retained, they produce higher fluxes of ENAs from this region and form the bright ribbon seen by IBEX.”

Full Story: http://www.swri.org/9what/releases/2013/ribbon.htm
Also: http://www.eos.sr.unh.edu/news/indiv_news.shtml?NEWS_ID=1370