Like city lights blinding the night sky, the sun blocks out a lot of the signals from our galactic neighborhood. Our star and its magnetic fields shield the planets from cosmic rays and the interstellar wind — by and large a good thing, but it's somewhat frustrating if you want to study the galaxy in greater detail. We cannot see, for instance, the hydrogen signals that serve as the birth pangs of stars in our neighborhood. Until now — the Voyager spacecraft have seen it for the first time.
The pangs in question are Lyman-alpha emissions, a phenomenon that occurs when single-electron hydrogen ions change their energy states. Lyman-alpha (Lyα) lines are most often seen in very distant galaxies, meaning very young galaxies, and often the type of galaxies thought to be precursors to Milky Way-like ones. (They're also used for studying dark matter distribution, but that's another topic.)
Alpha emissions are considered an indicator of star formation (and some other interesting phenomena) because they interact with and compress cold dust clouds and gas. So they would be a useful thing to study in our own galaxy, because they could provide information about the Milky Way's star-formation rate, among other characteristics.
The first glimpse of local Lyα lines is now the Voyagers' latest feat. The spacecraft are at the very edge of the solar system, and they have been noticing some bizarre things at the frontiers of interstellar space.
At roughly 40 AU — the mean distance of Pluto — the spacecraft's spectrometers started to notice these galactic emissions. And they're coming from the general direction of stellar nurseries, just as predicted. The Lyα hot spots span the constellations Scorpius and Ophiuchus, for those of you who are curious. Rosine Lallement and colleagues at the Paris Observatory and Université Versailles-St Quentin in Guyancourt, France, describe their findings in this week's issue of the journal Science.
So what is the point of all this? Understanding the local Lyα field can serve as a kind of cosmic yardstick, for one thing. Scientists can start to compare the Milky Way's star-formation rates and Lyα lines with other galaxies, and make comparisons to other star-forming regions in the universe.
"In the case of our Galaxy, a huge amount of information is available on stars, gas and dust. Milky Way Lyα data can be used to test the complex radiative transfer models that are developed for distant galaxies," the authors say.
Now for the bad news: The Voyagers aren't able to collect any more of this data, because they're running out of power, notes physicist Jeffrey L. Linsky at the University of Colorado-Boulder. Voyager 2's spectrometer has been shut off, and Voyager 1's can't scan the sky anymore, so it, too, will likely shut off soon. There's a bit more data that remains to be analyzed, but any new observations will have to be made by a new explorer, Linsky notes in an accompanying article in Science.
That will be up to NASA's New Horizons spacecraft, which is en route to Pluto for a 2015 arrival, and has a spectrometer that could make some of these hydrogen measurements.
So far out at the edge of interstellar space and we can't even get readings anymore. This is definitely more reason to get out into the universe. We won't be able to accurately study these things with limited capability subluminal velocity probes.
Exactly why an FTL vehicle should be built! We could be at Pluto in under a minute ;p
no really you think a ftl ship should be built huh, not so fricking easy as far as we lmow it its impossible, there might be a way around the problem like wormholes warp s or whtnot but...
no one knows yet how to do so
Figure out how to go lightspeed or faster even and youd be the richest man on earth heck just figure out a much lower cost way to orbit would do that
To say that FTL is impossible as far as we know is completely false. There is actually a proven mathematical formula that shows just how FTL is possible and what is needed to achieve this. Technically FTL is possible right now if we could produce the energy needed to power the drive, which at this point is calculated to be around the entire output of the planet earth for one jump. Before you say something is impossible you should do your research quesio2.
go to youtube and search Michio Kaku: Faster than light speed is possible
check out the vid and learn something.
More important than all of those technologies is bringing about practiced methods to be truly balanced in our consumption/production. Until we do this we will never be able to create the self sustaining environment necessary for any sort of long range space travel/colonization. At this point we can't even keep a handful of people on an orbiting tin can alive for more than 6mo-1yr without constant supply lines.
This is all the more reason that we need to expedite the research in lunar colonization. The moon is the perfect proving ground for these technologies. It is the harsh unforgiving territory requiring the environmental balance, but close enough that everyone isn't completely screwed in the event of catastrophic failure.
At this rate however i fear that the moon will more likely be the future venue of pirate governments and corporations seeking mineral rights rather than a light for future exploration.
we need to either get the politicians out of NASA and scientists back in, or burn it to the ground and let the corporations fight over the ashes.
Its amazing when you realize that this is 1970's technology that got it there, imagine how far we could ho today.
Its amazing when you realize that this is 1970's technology that got it there, imagine how far we could how today.