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According to a new study published in The Monthly Notices of the Royal Astronomical Society, astronomers discovered that all disk galaxies rotate about once every billion years, no matter their size or mass. Astronomy Magazine reports: To carry out the study, the researchers measured the radial velocities of neutral hydrogen in the outer disks of a plethora of galaxies -- ranging from small dwarf irregulars to massive spirals. These galaxies differed in both size and rotational velocity by up to a factor of 30. With these radial velocity measurements, the researchers were able to calculate the rotational period of their sample galaxies, which led them to conclude that the outer rims of all disk galaxies take roughly a billion years to complete one rotation. However, the researchers note that further research is required to confirm the clock-like spin rate is a universal trait of disk galaxies and not just a result of selection bias. Based on theoretical models, the researchers also expected to find only sparse populations of young stars and interstellar gas on the outskirts of these galaxies. But instead, they discovered a significant population of much older stars mingling with the young stars and gas.

GeoGreg writes: On August 21, 2017, the contiguous United States will experience its first total solar eclipse since 1979. According to GreatAmericanEclipse.com's Michael Zeiler, approximately 200 million people live within one day's drive of the eclipse. Zeiler projects that between 1.85 to 7.4 million people will attempt to visit the path of totality. As the eclipse approaches, articles are appearing predicting the possibility of automobile traffic jamming rural roads. There is also concern about the ability of rural cellular networks to handle such a large influx. AT&T is bringing in Cell On Wheel (COW) systems to rural locations in Kentucky, Idaho, and Oregon, while Verizon is building a temporary tower in Jackson Hole, Wyoming. The disruption could be frustrating to those trying to get to the eclipse or share their photos via social networking. If cellular networks can't handle the data, apps like Waze won't be much help in avoiding the traffic. If communication is essential near the eclipse path, Astronomy Magazine recommends renting a satellite phone.

Mikkeles quotes a report from CBC.ca: Vera Rubin, a pioneering astronomer who helped find powerful evidence of dark matter, has died, her son said Monday. She was 88. Vera Rubin found that galaxies don't quite rotate the way they were predicted, and that lent support to the theory that some other force was at work, namely dark matter. Rubin's scientific achievements earned her numerous awards and honors, including a National Medal of Science presented by then-president Bill Clinton in 1993 "for her pioneering research programs in observational cosmology." She also became the second female astronomer to be elected to the National Academy of Sciences.

Flash Modin writes: In 1936, twenty years after Albert Einstein introduced the concept, the great physicist took another look at his math and came to a surprising conclusion. 'Together with a young collaborator, I arrived at the interesting result that gravitational waves do not exist, though they had been assumed a certainty to the first approximation,' he wrote in a letter to friend Max Born. Interestingly, his research denouncing gravitational waves was rejected by Physical Review Letters, the journal that just published proof of their existence. The story shows that even when Einstein's wrong, it's because he was already right the first time.

Flash Modin writes: NASA has poured considerable time and resources into Ridley Scott's The Martian — perhaps more than any other movie in history — going so far as to time a Mars human landing site selection workshop to coincide with the film. Jim Green, NASA's head of planetary sciences, was one of the consultants, with other astronomers fact checking every aspect of the set and script. The rockets, modules, and space suits were built — and 3-D printed — with heavy guidance from NASA. The filmmakers even hired Rudi Schmidt, former project manager of the European Space Agency's Mars Express spacecraft, to test the experiments done in the movie, including turning water into rocket fuel — which works. And, on the eve of The Martian's premiere at the Toronto International Film Festival this weekend, some of those scientists believe that this obsessive adherence to science fact will be enough to make NASA's Journey to Mars real for Americans. The space agency needs a Hail Mary because, in truth, the real program is nowhere near ready for prime time.

MarkWhittington writes: According to a story in Astronomy Magazine, NASA is contemplating sending flagship sized space probes to the so-called "ice giants" of Uranus and Neptune. These probes would orbit the two outer planets, similar to how Galileo orbited Jupiter and how Cassini currently orbits Saturn. The only time NASA has previously had a close encounter with either of these worlds was when Voyager 2 flew by Uranus in 1986 and then Neptune in 1989. Each of these missions would happen after the Europa Clipper, a flagship-class mission scheduled for the mid-2020s.

In 2013, the IceCube neutrino telescope detected dozens of high-energy neutrinos. Now, reports Astronomy magazine, researchers "have sorted through the billions of subatomic particles that zip through its frozen cubic-kilometer-sized detector each year to gather powerful new evidence in support of [those] 2013 observations confirming the existence of cosmic neutrinos." According to the report, Albrecht Karle from UW-Madison notes that while the neutrino-induced tracks recorded by the IceCube detector have a good pointing resolution, within less than a degree, the IceCube team has not observed a significant number of neutrinos emanating from any single source. ... “The plane of the galaxy is where the stars are. It is where cosmic rays are accelerated, so you would expect to see more sources there. But the highest-energy neutrinos we’ve observed come from random directions,” said Karle. “It is sound confirmation that the discovery of cosmic neutrinos from beyond our galaxy is real.”

Flash Modin writes: English cities are hard up for cash as the national government dolls out cuts. And in response, the country's councils — local governing bodies — have slashed costs by turning off an estimated 750,000 streetlights. Fans of the night sky and reduced energy usage are happy, but the move has also sparked a national debate. The Automobile Association claims six people have died as a direct result of dimming the lights. But a new study released Wednesday looked at 14 years of data from 63 local authorities across England and Wales and found that residents' chances of being attacked, robbed, or struck by a car were no worse on the darker streets.

Flash Modin writes: NASA built the twin Voyager spacecraft for a rare planetary alignment that put Jupiter, Saturn, Uranus, and Neptune within reach at once. Originally, Voyager 1 was programmed to see Pluto in 1986, but managers targeted Saturn's planet-like moon Titan instead. That choice made Pluto impossible by vaulting Voyager 1 from the orbital plane. Interestingly, Voyager 2, which couldn't reach Pluto, made the case for New Horizons by revealing Neptune's moon Triton as a kidnapped Pluto. "I'm very glad that they chose not to go to Pluto in 1986," says New Horizons head Alan Stern. "We'll do a better job at Pluto with modern instruments than they would have, and they did a much better job at Saturn..."

On June 8th, with a radio source beamed at the asteroid designated 2014 HQ124 (less formally, "the beast") while two other telescopes tracked that beam's reflections, NASA was able to gather high-quality images of the object as it zipped by a mere 776,000 miles from Earth. (Some asteroids are closer, and a vast number of them could soon be better known, but none have allowed as good an opportunity for radar obvservation.) Astronomy Magazine's account adds a bit more detail: To obtain the new views, researchers paired the 230-foot (70m) Deep Space Network antenna at Goldstone, California, with two other radio telescopes, one at a time. Using this technique, the Goldstone antenna beams a radar signal at an asteroid and the other antenna receives the reflections. The technique dramatically improves the amount of detail that can be seen in radar images. To image 2014 HQ124, the researchers first paired the large Goldstone antenna with the 1,000-foot (305m) Arecibo radio telescope in Puerto Rico. They later paired the large Goldstone dish with a smaller companion, a 112-foot (34m) antenna, located about 20 miles (32km) away. ... The first five images in the new sequence — the top row in the collage — represent the data collected by Arecibo and are 30 times brighter than what Goldstone can produce observing on its own.

mbstone writes "Scientists at the University College of London — where argon was originally discovered in 1894 — have now found spectroscopic signatures of molecules of argon hydride (ArH), said to be produced via explosive nucleosynthesis in a core-collapse supernova in the Crab Nebula. The post-supernova molecular dust was observed by the Herschel Space Observatory shortly before it ran out of coolant in April.."

xyz writes "A joint project of NASA and the German Aerospace Center has developed a highly modified Boeing-747SP aircraft to carry a 2.5-meter (98.4 inch) infrared telescope. The project SOFIA (Stratospheric Observatory For Infrared Astronomy) will observe radiation in the wavelengths from 0.3 microns to 1.0 millimeters, spanning the visible, infrared, and sub-millimeter portions of the electromagnetic spectrum. The observations will be taken at an altitude of 40,000 to 45,000 feet (12 to 14 km) which is above 99.8 percent of the water vapor in Earth's atmosphere, thus giving it a greater range of observations." Update: 10/31 13:27 GMT by T : Mea culpa -- headline changed to reflect that this telescope is intended for looking out at space rather than down at the Earth.

jcasman writes to mention an article at Astronomy.com discussing the now on-the-move Mars rovers, which have been effectively in hibernation over the long Martian winter. Spirit has been stationary in the Columbia Hills area, just barely powered up and taking the finest panoramic shot of the planet to date. On the other side of the world, Opportunity has been skulking around the Victoria crater. Scientists have been getting to know the area before attempting to send Opportunity into the geographical feature itself. "Opportunity now is traversing Victoria's rim, and mission scientists are naming features they find after places visited by Ferdinand Magellan and his crew during the first circumnavigation of Earth. (Victoria Crater itself is named after the lone ship that completed Magellan's quest.) [Steve Squyres of Cornell University] and his team are committed to driving Opportunity into the crater eventually, if they're sure the rover will be safe -- in other words, that they can get it out again. Squyres is confident they can, and he thinks it will be sooner rather than later."

Neil Halelamien writes "Astronomy Magazine reports that an international team of astronomers has proposed an alternative to sending a robotic or human repair mission to the ailing Hubble Space Telescope. Their proposal is to build a new Hubble Origins Probe, reusing the Hubble design but using lighter and more cost-effective technologies. The probe would include instruments currently waiting to be installed on Hubble, as well as a Japanese-built imager which 'will allow scientists to map the heavens more than 20 times faster than even a refurbished Hubble Space Telescope could.' It would take an estimated 65 months and under $1 billion to build, less than the estimated cost of a service mission."

An anonymous reader writes "Scientists at the University of Zurich predict that our galaxy is filled with a quadrillion clouds of dark matter with the mass of the Earth and size of the solar system. The results in this weeks journal Nature, also covered in Astronomy magazine, were made using a six month calculation on hundreds of processors of a self-built supercomputer, the zBox. This novel machine is a high density cube of processors cooled by a central airflow system. I like the initial back of an envelope design. Apparently, one of these ghostly dark matter haloes passes through the solar system every few thousand years leaving a trail of high energy gamma ray photons."

An anonymous reader submits "A comet discovered only this summer is brightening quickly and already visible to the unaided eye. Comet Macholz should be visible to the unaided eye until late January. On the night of January 7 - 8, it will sail about 2 degrees (4 Moon widths) to the west of the easily recognisable Pleiades star cluster, often known as the Seven Sisters. It will be at its closest to Earth Jan. 5-6, 2005, when it will be 32 million miles away." (Mentioned a few days ago, too.)

barakn writes "Using the Crab Nebula as an x-ray source, scientists have observed Titan's x-ray shadow to get a preliminary estimate of the extent of its outer atmosphere. On the same page, another article discusses the possibility that the hydrocarbon seas of Titan bear waves, albeit slow-moving and widely spaced, 7 times higher than waves on Earth (additional wave links here, here, and here). And Cassini-Huygens has snapped a photo of Saturn showing "two small, faint dark spots" in the southern hemisphere (this link has convenient arrows pointing at them, or here). Cassini-Huygens will achieve Saturn orbit insertion on July 1st. Huygens will detach and enter Titan's atmosphere in January, 2005."

Henry writes "New Scientist is reporting that a JPL team has measured the recoil effect of an asteroid caused by the Sun in the process of re-emission of absorbed sunlight as heat. Astronomers believe this phenomenon, known as the Yarkovsky Effect, has brought asteroids - which are otherwise mainly located in and near the belt - towards Earth. This effect on asteroids was previously predicted, but this is the first proof."

Roland Piquepaille writes "On this Fourth of July, it's usual -- at least in the U.S. -- to watch fireworks. But I want to invite you to see very special ones, celestial fireworks discovered by the Hubble Space Telescope. Astronomy Magazine has the story. "In a newly released image, the Hubble Space Telescope peers into a neighboring galaxy to capture a gorgeous view of a supernova remnant called LMC N 49. Also known as DEM L 190, the nebula lies within the Large Magellanic Cloud approximately 160,000 light-years away." Read this summary for more details and a nice illustration from the Hubble Heritage Team. You can find additional tons of information at this Hubble Heritage Project page."

xihr writes "Astronomers have discovered a new moon of Jupiter, bringing its known retinue of satellites to a whopping 40. The new moon, designated S/2002 J1, is only 3 km wide, and has a highly inclined and eccentric orbit. Astronomy.com has the story."

Tonight's Slashback includes updates on the state of MPlayer, Google's API release, DIY backyard transportation, and (thanks to politech) the "hidden camera" bill. Oh, and apparently, Mars is not the lush, green paradise you thought it might be. Read on for the details.

But what about the nude Russian girls who apparently need me? happyclam writes: "The text of the "hidden camera" bill has been posted at politechbot.com. Although we have already beat this one to death, I found the actual bill worth reading. One thing that had not been mentioned is that it allows for civil and criminal liability for spammers who email sexual advertisements without proper markings. Although I still prefer positive labeling (e.g. "kid-safe(tm)") to negative labeling (e.g. "socially questionable"), this bill does, I think, have a few good points to it. Read it."

DVDs want to be free. An Anonymous Coward writes: "According to this email and the latest news the mplayer source code is finally 100% GPL compliant. Maybe an official Debian package will finally be released as well instead of the marillat release. Work on integrating the open source Xvid MPEG4 codec is coming along nicely as well."

Gravity always wins, but likes to play. mzdial writes: "On March 14 you did a piece on this Southern Indiana's man love of roller coasters and how he created his own in his backyard! The Indianapolis Star has done a wonderful story with video and photos about this wonderful contraption. You can find the article here."

They're greedy for hits. ruvreve writes "A follow-up to the recent article about Google's release of an API. This article talks about the apparent success of releasing the API. It mentions that about 10,000 people have signed up and they have received 25 implementations in the first week. It goes on to talk about how Google needs to capitalize on the ability to provide a 'profitable' web service and maintain its position as the number-one search engine."

Chasing green, wet shadows. young-earth writes "In a disappointing followup to this story, an article on astronomy.com shows that what was thought to be chlorophyll on Mars found in the Pathfinder expedition was most probably artifacts of the processing model used. However future missions will profit from the work being done now: "...developing new methods to enable future rovers to select appropriate targets on the martian surface for further spectroscopic or close-up microscopic examination". So maybe in another mission..."

PhxBlue writes: "Astronomy.com has released a report, submitted to the 5 April Science magazine, that an asteroid known as 1950 DA has 1:300 odds of impacting Earth and causing widespread devastation. The good news is, the impact wouldn't happen until 16 March 2880; and the solutions suggested by the scientists don't involve Tea Leoni or Bruce Willis."

PhxBlue writes: "Astronomy.com has released a report, submitted to the 5 April Science magazine, that an asteroid known as 1950 DA has 1:300 odds of impacting Earth and causing widespread devastation. The good news is, the impact wouldn't happen until 16 March 2880; and the solutions suggested by the scientists don't involve Tea Leoni or Bruce Willis."

XorNand writes: "Astronomy.com is reporting that a scientist, using astronomy simulation software, has correlated ancient stone carvings in Ireland to a solar eclipse that occurred on November 30, 3340 BC. Also interesting are the other pieces of evidence in the area, including the charred remains of 48 people found nearby that were the result of a panicked attempt to appease the sun gods."

chrisleonard writes "We all know that global warming is supposed to heat the planet up, but did you know that it might also slow it down? According to a report from Belgium's Royal Observatory (as reported here by astronomy.com), if the days seem a little longer to you than they used to, it might not be just old age catching up with you. Would it be wrong to call the interaction of the world's warming temperatures and its slowing rotation ... a snowball effect?"

Space.Com, Astronomy Magazine and The American Meteor Society all have tons of information, viewing guides and historical perspectives for you to peruse in anticipation of tonight Lonid meteor shower. Many are predicting a once in a lifetime event, as the Earth is expected to swing through 3 debris trails laid down by Comet 55p/Temple-Tuttle. One article mentions that up to 10,000 events per hour could be in the offing. So if you feel like staying up till 2am pst (10 ut) you'll be able to check it out. I know we've been hyping this event, but, well, we are okay with this.

tkrotchko writes "The first meteor shower of the year peaks early tomorrow morning. The Lyrid Meteor shower started April 16th but peaks Sunday morning between 2 AM and 5 AM. MSN has a good overview of the Lyrid, but if you intend on watching, astronomy.com has a map showing you exactly where to look. My experience with meteor showers in the past has been hit or miss; most are a bust, but occasionally, there are some pretty spectacular showers."

nachoworld writes "One of the stars of the Pleiades cluster, Merope, has been running through the nebular cloud, IC 349, in what some scientists call an "interstellar bullet," since the star is tearing up the insides of the nebular cloud for us humans back on Earth to analyze. Read about it here. Hubble Space Telescope has caught some dramatic pictures."

nachoworld writes: "In a similar vein to the neutron star article posted earlier today, this more interesting NS has emitted a 3-hour long (1000x longer than normal) explosion by fusing the mass of its mostly helium neighbor. In that pluto-sized ejection, the NS emitted enough energy to keep the sun burning for 20 years. On a side note, this is the one and the same neutron star of 4U 1820-30, which is the fastest spining binary known to man (11-minute cycles)."