NASA may have to bust out an Enigma Machine to figure out what's going on with the Voyager 2 probe, the second most distant human-made object in space. On May 7th mission managers at the Jet Propulsion Laboratory in Pasadena announced that the craft recently started sending back science data in a format no one on Earth can decode. Voyager 2 has been switched to sending back only health and status reports while engineers at home try to figure out the glitch. t's no easy task, considering that Voyager 2 is about 8.6 billion miles (13.8 billion kilometers) from Earth. At that distance, it takes about 13 hours for a signal to reach the craft, and another 13 hours for it to reply. What the scientists do know so far is that the problem is in a part of the craft called the flight data center, the instrument that formats information for transmission to Earth. Voyager 2 launched in 1977, and it's been on the job exploring planets, moons, and now the very edge of the solar system for almost 33 years solid. But according to AP, the best guess is that the craft's troubles are not age related, but cosmic-ray related.
Another discovery made by Voyager is the fact that 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," explains lead author Merav Opher, a NASA Heliophysics Guest Investigator from George Mason University. "This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all." The discovery has implications for the future when the solar system will eventually bump into other, similar clouds in our arm of the Milky Way galaxy. Astronomers call the cloud we're running into now the Local Interstellar Cloud or "Local Fluff" for short. It's about 30 light years wide and contains a wispy mixture of hydrogen and helium atoms at a temperature of 6000 C. The existential mystery of the Fluff has to do with its surroundings. About 10 million years ago, a cluster of supernovas exploded nearby, creating a giant bubble of million-degree gas. The Fluff is completely surrounded by this high-pressure supernova exhaust and should be crushed or dispersed by it.
"The observed temperature and density of the local cloud do not provide enough pressure to resist the 'crushing action' of the hot gas around it," says Opher.
So how does the Fluff survive? The Voyagers have found an answer.
"Voyager data show that the Fluff is much more strongly magnetized than anyone had previously suspected—between 4 and 5 microgauss*," says Opher. "This magnetic field can provide the extra pressure required to resist destruction."
The fact that the Fluff is strongly magnetized means that other clouds in the galactic neighborhood could be, too. Eventually, the solar system will run into some of them, and their strong magnetic fields could compress the heliosphere even more than it is compressed now. Additional compression could allow more cosmic rays to reach the inner solar system, possibly affecting terrestrial climate and the ability of astronauts to travel safely through space. On the other hand, astronauts wouldn't have to travel so far because interstellar space would be closer than ever. These events would play out on time scales of tens to hundreds of thousands of years, which is how long it takes for the solar system to move from one cloud to the next.
"There could be interesting times ahead!" says Opher.
more on: http://blogs.nationalgeographic.com/blogs/news/breakingorbit/2010/05/voyager-2-speaking-in-code.html
or: http://science.nasa.gov/science-news/science-at-nasa/2009/23dec_voyager/
Another discovery made by Voyager is the fact that 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," explains lead author Merav Opher, a NASA Heliophysics Guest Investigator from George Mason University. "This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all." The discovery has implications for the future when the solar system will eventually bump into other, similar clouds in our arm of the Milky Way galaxy. Astronomers call the cloud we're running into now the Local Interstellar Cloud or "Local Fluff" for short. It's about 30 light years wide and contains a wispy mixture of hydrogen and helium atoms at a temperature of 6000 C. The existential mystery of the Fluff has to do with its surroundings. About 10 million years ago, a cluster of supernovas exploded nearby, creating a giant bubble of million-degree gas. The Fluff is completely surrounded by this high-pressure supernova exhaust and should be crushed or dispersed by it.
"The observed temperature and density of the local cloud do not provide enough pressure to resist the 'crushing action' of the hot gas around it," says Opher.
So how does the Fluff survive? The Voyagers have found an answer.
"Voyager data show that the Fluff is much more strongly magnetized than anyone had previously suspected—between 4 and 5 microgauss*," says Opher. "This magnetic field can provide the extra pressure required to resist destruction."
The fact that the Fluff is strongly magnetized means that other clouds in the galactic neighborhood could be, too. Eventually, the solar system will run into some of them, and their strong magnetic fields could compress the heliosphere even more than it is compressed now. Additional compression could allow more cosmic rays to reach the inner solar system, possibly affecting terrestrial climate and the ability of astronauts to travel safely through space. On the other hand, astronauts wouldn't have to travel so far because interstellar space would be closer than ever. These events would play out on time scales of tens to hundreds of thousands of years, which is how long it takes for the solar system to move from one cloud to the next.
"There could be interesting times ahead!" says Opher.
more on: http://blogs.nationalgeographic.com/blogs/news/breakingorbit/2010/05/voyager-2-speaking-in-code.html
or: http://science.nasa.gov/science-news/science-at-nasa/2009/23dec_voyager/
