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Back in 1958, at the dawn of the space age, physicist James Van Allen discovered that the Earth is ringed by high-energy charged particles. Held in place by the planet’s magnetic field, these bands of radiation were named the inner and outer Van Allen Belts. They’re of particular interest to NASA as they pose a potential danger to spacecraft.
Now a NASA mission also named for Van Allen has found something new about his belts. By looping through them repeatedly, the twin Van Allen Probes discovered a third band of radiation.
Or at least there were three. The two spacecraft uncovered the previously unknown structure in September. It consisted of fast-moving electrons, situated between the two previously known Van Allen Belts. The discovery was reported in the journal Science. [Daniel N. Baker et al., A Long-Lived Relativistic Electron Storage Ring Embedded in Earth's Outer Van Allen Belt]
But the new structure is no longer. Four weeks after the probes found it, the third ring was wiped out by a strong shock wave emanating from the sun. Still, the unexpected finding shows that the Van Allen Belts are more complex and variable than had been assumed. And that seemingly well-established knowledge about space still may have the capacity to surprise.
—John Matson
[The above text is a transcript of this podcast.]
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3 Comments
Add CommentI am really confused about the existence of time. The future directly converts into the past and no time for the present, where as we all live in present and present never exist. The time is just a relative term and not an absolute, it is just the comparison of the motion and speeds. our time on earth is just a comparative rate of speed to the motion of earth in 24 hours, nothing passing other than earth.In the universe time is just relative, a minute somewhere can be years at other place. Irrespective of our observation as relative if we consider the universe as a whole we cant see any time. Time only defines the contrast between speeds and it is just our observation and when we change the frame it becomes having no useful value. I am not a big scientist to prove the time not as the fourth dimension of space time but my own feelings are that it is just some comparison between the motions and nothing absolute in the universe. Probably time is illusion. If we can go out of the universe we are free of time.
Reply | Report Abuse | Link to thisMy other curiosity is whether the life generated on the earth or it was seeded form out side of earth, may be from Van Allen belt transferred to the earth through broken rock.
Reply | Report Abuse | Link to thisSalem, Muhammad...the notion of "time" has confounded thinkers for millenia. You might like to read from Julian Barbour's works, e.g.
Reply | Report Abuse | Link to thishttp://fqxi.org/data/essay-contest-files/Barbour_The_Nature_of_Time.pdf
Regards, JLR