To very simple questions, there are often no easy answers.

Where, for example, is actually our solar system to the end? Somewhere far behind the last planet Neptune, it has to be, somewhere far behind the small degraded Pluto and all the other objects of the so – called Kuiper belt, the lumber room of our cosmic neighborhood, by the Nasa probe “New Horizons” planet flies.

A reference to the fact that it is at least in the direction of the edge of the solar system on the way, however, there is – and has to do with the solar wind. Our star sends a stream of particles in space: protons, electrons and helium nuclei. At the height of the earth, depending on the activity of our sun in about one to ten million particles per cubic meter. This solar wind is practically way also a protective case, which keeps most of the dangerous cosmic radiation away from us.

“Everything we see is new” move

the more the particles of the solar winds but the sun, the more they are decelerated. This is because the sun and planets move, in turn, by the so-called interplanetary Medium, consisting mainly of Gas and dust in low concentration. And somewhere, in about 120 Times further from the sun than the earth, the stream of Particles from the Depths of the universe more powerful than the weakening of the particles of the solar wind.

our solar system is not the end, but the inner area of influence of our star.

And this Zone, the so-called Heliopause, the Nasa spacecraft “Voyager 2”, apparently, recently. At the annual meeting of the American Geophysical Union, Washington meeting, researchers from the U.S. space Agency, have presented the findings on Monday. They are based mainly on measurements of the “Plasma Science experiment” aboard in the summer of 1977, launched the probe.

“Voyager 2” outside of the solar system

“By working with ‘Voyager 2’ I feel like an Explorer,” says John Richardson, of for the Instrument, competent the chief scientist from the Massachusetts Institute of Technology in Cambridge. “Everything we see is new.”

The “Plasma Science Experiment” still works today – even if, in the meantime, a whole 16 hours and 36 minutes elapse before the signals from the probe to reach the antennas of the Deep Space Network on earth. As long as it takes for the radio waves, the back 18 billion kilometers – even though you are at the speed of light. The exact distance of the probe, you can find here.

waste of the solar wind particles

“Voyager 2” is the second man-made object that reached the area of the Heliopause. About six years ago, it was already managed your twin, “Voyager 1”. This was faster, because they flew off on a different course from the earth – and so the edge of the solar system rather. The “Plasma Science Experiment” on Board “Voyager 1”, however, was failed in 1980 – why is Nasa so fond of the current data from the “Voyager-2”.

The meter was on 5. November reported a strong drop in the number of the measured solar wind particles 25 particles per second to about 5. Since these particles can be in the environment, “Voyager 2” even less evidence. Also measurements of other devices on Board the spacecraft, you look at the magnetic field and cosmic radiation, indicate that these have reached the area of the Heliopause is actually.

waste of electric current

These other values can also be used with the “Voyager 1” to compare. Differences were in the Detail project scientist Ed Stone from the California Institute of Technology in Pasadena: “One of the good things of ‘the Voyager’ tells that we are always surprised.” The differences could for example be explained by the fact that the probes have reached the Heliopause at different locations and to different phases of the solar cycle. “I would have been surprised if we had seen the same thing.”

About ten years until the end of the probe

One must, however, be said that The solar system is the Heliopause yet. Do not approach way. Far beyond the planetary orbits, far beyond the Kuiper belt called the Oort cloud. Also which objects are affected by the Gravitation of the sun. Some of the comets should originate from here. The Oort cloud is approximately 100,000 times further out into space, extend as the distance from the earth and the sun.

reached by “Voyager-2” to the beginning of the Oort cloud, is likely to pass, according to estimates of Nasa, about 300 years. And until the probe has left the solar system, in fact, it may take even a further 30,000 years.

as long As the radio nuclide battery will not keep on Board of the probes. Now Voyager 2 is “” cold, at the same time the power supply is dropping constantly. “We believe that we have five or six, maybe even ten years,” says Suzanne Dodd, from the Jet Propulsion Laboratory in Pasadena. You will, however, have to turn off and gauges, in order to save energy, says Dodd: “We have difficult decisions ahead of us.”

Sam Yoon has many years of experiences in journalism. He has covered such areas as information technology, science, sports and politics. Yoon can be reached at 82-2-6956-6698.