Voyager Has Left the Building....

Kall asked the question in last week's RUNDOWN segment, where exactly IS Voyager?

Well now, according to Reuters, new research indicates that the craft left the confines of the Solar System last year.  Making it the first man made object to do so.  

This new research is based on conclusions by physicist Marc Swisdak of  the University of Maryland.  Up until this point, scientists have based Voyager's position to magnetic fields.  These fields, according to computer models, will flow away from the sun as long as Voyager is in the Solar System. These fields should stop and the flow then should come from the interstellar medium and flow towards the solar system.  

However Swisdak's findings suggest that Solar System magnetic flows and interstellar's flow are aligned enough that "you can actually pass through without seeing a huge change in direction,"

If this is indeed the case then Voyager's position can only be based upon the amount of particles from Sol or cosmic rays flowing toward the Solar System from the interstellar medium.  This very scenario occurred with Voyager last year, hence the conclusion by Swisdak that Voyager has indeed left the Solar System and did so last year when Voyager detected a sharp drop in particles from Sol and   a corresponding increase in particle influx toward the Solar System. 

From the article:

• Voyager lead scientist Edward Stone, now retired from NASA's Jet Propulsion Laboratory in Pasadena, California, said Swisdak's research is interesting but different computer models are portraying different scenarios to explain the Voyager data.

Read complete Reuters article HERE

Jupiter to Blame for Mars Being so Small?

It would appear that Jupiter may be to blame for the planet Mars being so low in mass, when in truth it should be somewhere between Venus and Earth in mass. Also the gas giant is most likely responsible for the unusual makeup of the asteroid belt.

Now first is the fact that we have found an inordinate amount of systems that have gas giants very close in to their primary. Instead of it being an aberration, this makeup would appear to be more normal than not.

A research team from Southwest Research Institute ran a series of simulations that demonstrated the effects of Jupiter moving in towards the Sun during the early days of the solar system.

If, shortly after Jupiter formed, was drawn in towards the sun only to reverse the inward spiral at about 1.5 times the distance of Earth's orbit by the formation of Saturn, then most of the planet building material would have been swept up except what existed inside of Earth's orbit. Limiting what was available for Mars.

The question that isn't answered so far is, does this model also explain the asteroid belt?

Dr. Kevin Walsh, leader of the Southwest Research Institute team said: (from the IO9 article)

• "...we started to do a huge number of simulations. The result was fantastic. Our simulations not only showed that the migration of Jupiter was consistent with the existence of the asteroid belt, but also explained properties of the belt never understood before."

The team's conclusions are that not only does their roving Jupiter model explain the lack of mass in Mars but also the existence and weird makeup and distribution of elements.

Nature.com link, IO9 complete article

Outside In - Saturn flyby

The Dvice blog brought this neat project to my attention. The Outside In project is a full-length feature IMAX film that aims to take the watcher on a breath taking tour of the Solar System. What will make this project truly unique will be the source material. No CGI will be used. Instead the movie will be built up from literally thousands of photographs taken of the Solar System by a variety of space craft. The whole project is dependant completely on donations, but instead of waiting for the money the film's producers have worked on completing part of the film consisting of a fly-by of the Saturn system using Cassini photos. This short alone is spectacular! The composites are flawless in my opinion. Check this short out and take a look at the film's web site here.

Outside In Concept Teaser Trailer from stephen v2 on Vimeo.

New Asteroids found in Neptune's Orbital "Dead Zones"

Here is some space trivia that I have always found fascinating. Every planet / sun combination has a few "weird" places in their orbits. These areas are for all intents gravity free zones. These places quite literally are gravity balanced places where the gravity attraction of the sun and the planet are canceled out. What is fascinating is there are not just one but five for every planet orbiting around the sun (and of course if there are moons, those too play into even more neutral areas) They exist several degrees ahead and behind the planet, 180 degrees or on the exact opposite side of the sun, between the sun and the planet and finally at a point out side the orbit of the planet where the planet and sun's gravity cancel each other out. These areas are called Lagrangian points or L points for short. The most studied are L4 just ahead of a planet and L5 behind, because they are the most stable.1 (L1 is between the planet and the sun, L2 is at the point outside the orbit with the sun & planet balancing and L3 is at 180 degrees)

L4 &5 ten to gather the most junk, but up to this point L4 & 5 points of Neptune's orbit have been very difficult to study as they are so very far away and Neptune's L5 is on direct line of sight with the bright center of our galaxy.

Scientist's have been persistent and with the recent blocking of the light from the galaxy center being blocked by dust have discovered a bonanza of large objects in Neptune's L5. These "Trojan" asteroids are about 100 kilometers in size and that there are about 150 Trojans of similar size. These Lagrangian points as so stable that these objects were most likely captured during the formation of our solar system.

What makes this discovery particularly noteworthy is best described by the article on IO9

• (the Trojan objects were likely captured)...before planets were brought onto a single orbital plane and Neptune itself revolved around the Sun in an orbit similar to that of the asteroids today. As the planets eventually locked into their current orbits, the asteroids were "frozen" in place at the points, but their eccentric orbits remained as evidence of a more chaotic time in the history of the solar system.

Now that is what I call cool stuff. Because up to this time I had assumed that there had always been a single orbital plane and the planets just cleaned up around them......Now we find that not only did some of the planets orbit off the plane but may have had non keplerian orbits to boot! Good stuff!

read complete IO9 article here

Voyager 2 is confused....

The Voyager 2 prob has become somewhat confused in its old age. According to an article in Tech Republic the 30 year old explorer has begun sending back confusing data, almost certainly due to the result of cosmic rays hitting the probe's computer memory and causing it to report conflicting data. The good news is that the command and control sections of the craft are still functioning so trouble shooting should be able to figure out the area of malfunction. Voyager 1 and 2 are still of major interest to the scientific community mainly because they are due, in the next five years, to exit the solar system ( the solar system's boundaries are determined by the " heliopause " or the area where the sun's solar wind is equaled by that of stellar wind) .

The two craft have traveled apx 13 billion kilometers which means that it takes 26 hours to send a command and receive a reply. Think about that....in 30 years, the fastest craft that man ever built has only traveled 13 hours away and hasn't even left the back yard yet, let alone the neighborhood. Space is incomprehensibly vast. Even if we construct a craft to go a hundred times faster, it would still take thousands of years to leave "the neighborhood".

Mercury and Mars - Leftover Planets.

Adding another wrinkle to the difficult task of categorizing planets, a new computer model suggests that Mercury and Mars were formed from particles ejected during the formation of Earth and Venus.

The computer model by UCLA astronomer Brad Hansen was a result of flaws in the traditional of assumption of an evenly distributed particle disk during planetary formation. One obvious flaw being that this should have resulted in the rocky planets all being essentially the same size. Hansen "proposes that the dust disk fragmented into bands of debris at various distances from the sun—much like the rings of Saturn." In this theory Earth and Venus formed in one large band, hence their similar sizes, while Mercury and Mars were formed mostly from particles ejected from the main band by the gravity of the larger planets.

One good aspect of theory is that it makes predictions that can be tested. This model predicts that "the composition of the solar system's four rocky planets should be strikingly similar" while the standard model predicts that they should vary in accordance with their distance from the sun.

<Read more at National Geographic>

The 3 Bears effect on our Solar System

As Goldilocks, and now a new computer study, found out - certain things have to be just right. For our lady in curls, it was the oatmeal, chairs and beds, but for our solar system, far from being average, events had to fall into place just right for it to form the way it did. Leading ultimately to our arrival on the scene.

In an article in Science Daily, astronomers from Northwestern University are the first to run computer simulation of solar system formation, from beginning to end, starting with the generic disk of gas and dust that is left behind after the formation of the central star and ending with a full planetary system.

Recently published in the journal Science, their study showed that the average solar system's genesis was filled with as they put it a great deal of "violence and drama", but that the formation of something like our solar system required conditions to be "just right."

The first extra solar systems discovered didn't look at all like our Solar System. The orbits were elongated and planets were not where they were expected to be. The simulation suggests that the early proto planets interacted more than was initially thought, fighting as it were for resources, being pushed relentlessly toward the central star and also reacting with each other to force some into the central mass or slingshoting others our of the system all together.

<- more ->

(Credit: NASA/Jet Propulsion Laboratory)

Smaller Version of the Solar System Is Discovered

From the NYTimes.com

Astronomers report that they had found a miniature version of our own solar system 5,000 light-years across the galaxy — the first planetary system that really looks like our own, with outer giant planets and room for smaller inner planets. In the newly discovered system, a planet about two-thirds of the mass of Jupiter and another about 90 percent of the mass of Saturn are orbiting a reddish star at about half the distances that Jupiter and Saturn circle our own Sun. The star is about half the mass of the Sun. Neither of the two giant planets is a likely abode for life as we know it. But warm rocky planets — suitable for life — could exist undetected in the inner parts of the system.

click here for complete article

Youngest Solar Systems Detected by Astronomers

Astronomers at the University of Michigan have found what are believed to be some of the youngest solar systems yet detected.

The systems are around the young stars UX Tau A and LkCa 15, located in the Taurus star formation region just 450 light years away. Using a telescope that measures levels of infrared radiation, the researchers noticed gaps in the protoplanetary disks of gas and dust surrounding these stars. They say those gaps are most likely caused by infant planets sweeping those areas clear of debris.

A paper on the findings by astronomy doctoral student Catherine Espaillat, professor Nuria Calvet, and their colleagues is published in the Dec. 1 issue of Astrophysical Journal Letters.