* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: Voyager crosses heliosphere


L

Posts: 131433
Date:
Voyager crosses heliosphere
Permalink  
 


NASA Holds Teleconference About Conditions At Edge Of Solar System
 
NASA will host a media teleconference at 1 p.m. EDT on Thursday, June 9, to discuss a new computer model that shows the edge of our solar system is not smooth, but filled with a turbulent sea of magnetic bubbles.
Read more



__________________


L

Posts: 131433
Date:
Permalink  
 

Boston University astronomer Merav Opher is to discuss the latest findings about the edge (the heliosheath) of the solar system.
New computer models of the solar system based on data from the Voyager space probes indicates that the heliosheath filled with a turbulent sea of magnetic bubbles.
The NASA media teleconference is scheduled for 1 p.m. EDT on Thursday, June 9, 1011.



__________________


L

Posts: 131433
Date:
Permalink  
 

Voyager: Still dancing 17 billion km from Earth

The extraordinary Voyager 1 spacecraft is demonstrating its nimbleness more than 30 years after leaving Earth.
At the astonishing distance of 17.4 billion km, the Nasa probe is the most far-flung object made by humans.
But it seems age and remoteness are no barriers to this veteran explorer.
Voyager is executing a series of roll manoeuvres to get one of its instruments into the optimum position to measure particles sweeping away from the Sun.

Read more

__________________


L

Posts: 131433
Date:
Voyager 1
Permalink  
 


Voyager Seeks the Answer Blowin' in the Wind

In which direction is the sun's stream of charged particles banking when it nears the edge of the solar system? The answer, scientists know, is blowing in the wind. It's just a matter of getting NASA's Voyager 1 spacecraft in the right orientation to detect it.
To enable Voyager 1's Low Energy Charged Particle instrument to gather these data, the spacecraft performed a manoeuvre on March 7 that it hadn't done for 21 years, except in a preparatory test last month.
At 9:10 a.m. PST (12:10 p.m. EST), humanity's most distant spacecraft rolled 70 degrees counterclockwise as seen from Earth from its normal orientation and held the position by spinning gyroscopes for two hours, 33 minutes. The last time either of the two Voyager spacecraft rolled and stopped in a gyro-controlled orientation was Feb. 14, 1990, when Voyager 1 snapped a family portrait of the planets strewn like tiny gems around our sun.

Read more

__________________


L

Posts: 131433
Date:
RE: Voyager crosses heliosphere
Permalink  
 


Title: Voyagers 1 and 2 in a Shrunken and Squashed Heliosphere
Authors: W.R. Webber, D.S. Intriligator

We have extended our earlier calculations of the distance to the Heliospheric Termination Shock (HTS) - which covered the period from the launch of V1 and V2 in 1977 to 2005 - to the period from 2006 to 2011. During this latter period the solar wind speed, ram pressure and magnetic field decreased to the lowest levels in recent history, related to the sunspot minimum in 2008-2009. The HTS distance has decreased correspondingly so that V1, which was crossed by the HTS at 94 AU in late 2004, would now, in early 2011, be expected to reach the HTS at a distance ~80 AU, when the HTS distance would be expected to be at its minimum. Similarly V2, which was crossed by the HTS at 84 AU in mid 2007, would, in early 2011, reach the HTS at a distance of only 74 AU. These distances, in early 2011, are ~15% less than those at which V1 and V2 initially reached the HTS. The distance to the Heliopause (HP) is more uncertain but recent calculations place its equilibrium distance at between 1.4-1.6 times the HTS distance. Allowing for an additional 1 year for the HP to reach its equilibrium minimum distance relative to the HTS would mean that, assuming this distance remains a constant fraction larger than the HTS distance, the HP distance would be at its minimum distance of (1.4-1.6) x 80 AU = 112-128 AU at V1 in early 2012. At this time V1 will be at a distance of ~120 AU so that there is a possibility that V1 could cross the HP and enter interstellar space at the time 2012.0 \pm 1 year. If the crossing does not happen during this time period, then it is unlikely that V1 will reach this defining boundary before about 2016 because of the expected outward motion of the HTS and the HP towards their more normal distances of 85-96 and ~120 -140 AU coincident with the maximum of the new sunspot cycle.

Read more (773kb, PDF)

__________________


L

Posts: 131433
Date:
Permalink  
 

NASA Probe Sees Solar Wind Decline En Route To Interstellar Space
The 33-year odyssey of NASA's Voyager 1 spacecraft has reached a distant point at the edge of our solar system where there is no outward motion of solar wind.
Now hurtling toward interstellar space some 10.8 billion miles from the sun, Voyager 1 has crossed into an area where the velocity of the hot ionised gas, or plasma, emanating directly outward from the sun has slowed to zero. Scientists suspect the solar wind has been turned sideways by the pressure from the interstellar wind in the region between stars.
The event is a major milestone in Voyager 1's passage through the heliosheath, the turbulent outer shell of the sun's sphere of influence, and the spacecraft's upcoming departure from our solar system.



__________________


L

Posts: 131433
Date:
Permalink  
 

Voyager Celebrates 20-Year-Old Valentine to Solar System

Image2-10.jpg
Expand (33kb, 620 x 500)
Credit:    NASA/JPL


On Feb. 14, 1990, NASA's Voyager 1 had sailed beyond the farthest planet in our solar system and snapped an image that was a parting valentine to our string of planets.
Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

The solar system is passing through an interstellar cloud that physics says should not exist. In the Dec. 24th issue of Nature, a team of scientists reveal how NASA's Voyager spacecraft have solved the mystery.

"Using data from Voyager, we have discovered a strong magnetic field just outside the solar system. This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all" - lead author Merav Opher, a NASA Heliophysics Guest Investigator from George Mason University.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Twenty years ago, Voyager 2 left Neptune behind. The robotic spacecraft had taken advantage of a rare alignment of the outer planets that enabled it to visit Jupiter, Saturn, Uranus and Neptune in a single shot.
Voyager 2 had launched before its sister ship, Voyager 1, on August 24, 1977. Voyager 1 lifted off just a few days later, on September 5, 1977, on a faster trajectory headed for Jupiter, Saturn and the latters enigmatic moon, Titan.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Winds of charged particles race outwards from the sun at 300,000 miles per hour. They are so faint that, here on the outer edge of the solar system, they would be undetectable if it were not for the very sensitive instruments carried by spacecraft.
From this distant, dark void, the sun is 100 times farther away than it is from Earth. Even so, our star is a million times brighter than Sirius, the brightest star seen from Earth. All around is a near-perfect vacuum, with only the most capable of instruments able to detect an ambient magnetic field that is 200,000 times weaker than the field back on Earth. To top off the loneliness factor, nothing from Earth has ever journeyed this far from home.

Read more

__________________
«First  <  1 2 3 4  >  Last»  | Page of 4  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard