Posts Tagged ‘citizen science’

Help Make Better Map of Global Light Pollution

22 Mar

You can help build the best global map of light pollution, the uniquely modern problem that has stolen starlight from most of the urbanized world.

From March 22 through April 6, the GLOBE at Night website will collect the public’s measurements of the night sky. Anyone can participate by comparing their local view of specific constellations with magnitude charts on the site. The event is in its sixth year, and organizers hope to surpass the 17,800 observations they collected in 2010.

“With half of the world’s population now living in cities, many urban dwellers have never experienced the wonderment of pristinely dark skies and maybe never will,” says the GLOBE at Night. “This loss, caused by light pollution, is a concern on many fronts: safety, energy conservation, cost, health and effects on wildlife, as well as our ability to view the stars.”

Baby sea turtles attracted by artificial light. (NIH)

Light pollution is caused by stray artificial light from sources that are too bright, poorly aimed or both. Similar to how sunlight makes the sky glow blue, artificial light scatters in the atmosphere to create a dull glow that obscures stars and celestial objects. Airborne pollutants exacerbate the problem.

Aside from the loss of stars from view, light pollution has more quantifiably dangerous sides. One model of Los Angeles suggests it destroys about 7 percent of smog-eating chemicals that build up in the dark, leading to a 5 percent jump in wheeze-inducing ozone pollution during the day. Other studies show artificial light can thwart animal migrations and negatively impact human health.

Satellites can assess artificial brightness from space, but the view is very different from the ground. By crowdsourcing measurements, GLOBE at Night aims to both create the most accurate map of how light pollution hides the stars and raise awareness of the problem. They also hope to spark a push for local artificial light ordinances, such as those passed in Flagstaff, Arizona, and other municipalities.

People living north of the equator can access the organization’s app to report night-sky conditions between March 22 and April 4. In the southern hemisphere, the window of opportunity is March 24 through April 6.

Images: 1) Historic and anticipated increases in artificial night sky brightness in the United States./NIH. 2) Worldwide measurements of light pollution submitted by 17,800 participants in 2010./GLOBE at Night.

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Citizen Scientists Make First Deep Space Discovery With Einstein@Home

12 Aug

While your computer is running idle, it could be finding new pulsars and black holes in deep space.

Three volunteers running the distributed computing program Einstein@Home have discovered a new pulsar in the data from the Arecibo Observatory radio telescope. Their computers, one in Iowa (owned by two people) and one in Germany, downloaded and processed the data that found the pulsar, which is in the Milky Way, approximately 17,000 light years from Earth in constellation Vulpecula.

“The way that we found the pulsar using distributed computing with volunteers is a new paradigm that we’re going to make better use of in astronomy as time goes on,” said astronomer Jim Cordes of Cornell University. “This really has legs.”

About 250,000 volunteers run Einstein@Home, on average donating about 250 teraflops of computing power — equivalent to a quarter of the capacity of the largest supercomputer in the world, says program developer David Anderson of University of California at Berkeley’s Space Sciences Laboratory, co-author of the Aug. 12 discovery announcement in Science.

Einstein@Home has been searching for gravitational waves in the data from the US LIGO Observatory since 2005, and since March 2009 has dedicated one-third of its power to searching for radio pulsars and black holes in the Arecibo data. As of this week, it will start dedicating half of its processing power to data from Arecibo, the world’s largest and most sensitive radio telescope, physicist Bruce Allen of the Max Plank Institute for Gravitational Physics in Germany and co-author of the study announced a press conference Aug. 12.

The new pulsar, dubbed PSR J2007+2722, is a neutron star rotating 41 times per second. Pulsars are birthed when stars five to 10 times as massive as our sun explode into a supernova and then collapse into stars composed almost entirely of neutrons.

The data from Arecibo was processed on the computer in Iowa June 11, and then also processed on a computer in Germany June 14 for validation. The finding was part of a larger search that returned results on July 10, which was the first time a human being was aware of the discovery.

Aerial view of the Arecibo Observatory radio telescope.

The person who looked at the results notified Greenbank Observatory in West Virginia, which immediately pointed their telescope at the new pulsar to verify it. Within hours, Arecibo Observatory in Puerto Rico also pointed their telescope at it.

“This is the first time I’ve worked closely with radio astronomers making a discovery,” said Allen. “It was like watching 5-year-olds tearing Christmas presents. Or like watching someone throw chunks of meat at starving sharks.”

Pulsars are named after the pulsing signals they send to Earth. The pulse comes from the spin and the magnetic field of the neutron star being on two different axes, which acts like an electric generator and creates a beamed signal that rotates like a lighthouse. Cordes says theoretical predictions are that only about 20 percent of the pulsars in the galaxy are detectable on Earth because the beam needs to point directly at us to be detected.

Often, pulsars have a companion star or neutron star that was originally born in the same cloud of gas. But this new pulsar doesn’t and is likely a disrupted recycled pulsar. This means the pulsar once had a companion star that it sucked matter from as the star swelled up into a red giant, which caused the pulsar to cycle faster (recycle). The red giant star then exploded into a supernova and blasted the pulsar away, leaving it alone in space (disrupted).

The new pulsar is one of around 2000 pulsars that have been discovered using radio telescopes in the past 43 years, said Cordes. He estimates there are 20,000 pulsars in the Milky Way that could be detected.

“I see this as a long-term effort where we’re going to find really interesting objects,” said Cordes. “We’d like to find a pulsar orbiting a black hole, or a pulsar orbiting another neutron star so that we can test some of Einstein’s predictions of the general theory of relativity”

You can become part of the effort by downloading BOINC. The program has been used to create 70 different distributed computing projects (almost every one in existence except Folding@Home), and you can decide what fraction of your spare computing power you want to dedicate to each of the 70 projects.

In case you need more incentive, Cordes announced that a second pulsar has been already been discovered in the last month by Einstein@Home users in the United Kingdom and Russia. He’s keeping details to himself for now.

“We have a very large data set,” Cordes added at the press conference. “We just need to cull through it, and Einstein@Home lets us use a much finer comb.”


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Images: 1) Screen shot of Einstein@Home/B. Knispel, Albert Einstein Institute. 2) Copyright Cornell University.

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