Beach bummer: toxic slime will hit Lake Erie again

Satellite image of a toxic algae bloom in Lake Erie in 2011, one of the worst blooms in recent years.MERIS/ESA, processed by NOAA/NOS/NCCOS

Slimy green mats of toxic algae will again threaten the western shores of Lake Erie later this summer, according to an algae forecast released today July 10.

The predicted Lake Erie algal bloom will be smaller than in the past three years, but still above the average for the past 12 years, according to the National Atmospheric and Oceanic Administration (NOAA) forecast. The algae are also expected to collect on certain shorelines instead of spreading out evenly across the lake, NOAA said in a statement. In previous years, the toxic algae have clung to the western third of the lake, in Ohio and southern Ontario.

This year's forecast calls for some 24,250 tons (22,000 metric tons) of blue-green algae to overtake Lake Erie's waters, while the average since 2004 is 15,430 tons (14,000 metric tons). [Photos of the Great Lakes: North America's 'Third Coast']

This is the third year the agency has forecast the amount of toxic slime that would choke Lake Erie during the late summer. The forecast is based on models of fertilizer runoff and satellite tracking of precipitation and snowmelt.

The noxious blooms occur when fertilizer runoff feeds the runaway growth of cyanobacteria, or blue-green algae. The algae are harmful to marine life and to humans. Decaying cyanobacteria suck up oxygen, creating dead zones. Some kinds of algae also emit toxins that damage or irritate the nerves, skin, liver and kidneys of humans and other animals. Lake Erie is the drinking water source for millions of people in the United States and Canada.

The lake suffered from severe algal blooms in the 1960s, but the thick mats disappeared after a water quality agreement was signed in 1972. The toxic algal blooms returned with a vengeance in 2000, due to changes in when and how farmers apply agricultural fertilizer, according to studies by researchers at the University of Michigan and other institutions. Scientists also think climate change is a factor, with Lake Erie's waters becoming warmer and more hospitable to algae.

"The reemergence of harmful algal blooms in Lake Erie is an ecological and economic setback for communities along the coast," U.S. Rep. Marcy Kaptur (D-Ohio) said in the statement.

View the original article here

Winds Delay Launch of Twin NASA Moon Probes Again (SPACE.com)

Windy weather has once again thwarted NASA's attempt to launch two gravity probes to the moon today (Sept. 10) on a mission to study the inside of the moon and its gravity field.

The two Grail spacecraft were scheduled to launch on an unmanned Delta 2 rocket from the Cape Canaveral Air Force Station in Florida this morning at 8:29 a.m. EDT (1229 GMT), but stubborn high-altitude winds – the same thing that forced NASA to stand down during initial launch attempts on Thursday (Sept. 8) – caused yet another delay.

A second opportunity to launch the Grail mission this morning is available at 9:08 a.m. EDT (1308 GMT), but if weather conditions do not improve, NASA will have to wait until tomorrow before they can try again. [Photos of NASA's Grail Moon Gravity Mission]

Another chance on Friday (Sept. 9) was called off to give engineers time to assess the rocket's propulsion system after a potential glitch was detected. After a series of reviews, the team concluded that there are no issues with the rocket or its propulsion system, NASA officials said.

The $496 million Grail mission will closely analyze the composition of the lunar interior, and the twin probes will make detailed and precise maps of the moon's gravitational field. The three-month expedition is expected to help scientists uncover clues of the moon's origin and evolution.

Grail's observations should also shed light on how other large, rocky bodies in the inner solar system were formed.

You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

View the original article here

Lions Kill and Go Away, to Kill Again Another Day (LiveScience.com)

Lions apparently flee the scenes of their crimes, withdrawing after successful kills while other potential prey are still on high alert, researchers have found by using satellites to track some of the deadly African cats.

This research into the minds of lions sheds light on why and when large predators move on from one hunting ground to the next, a crucial decision when the stakes are survival or starvation. In turn, such insights could lead to better designs of protected areas for African lions, whose numbers have shrunk by half in 30 years.

Deciphering the strategies of predators is difficult enough when they are captive, not to mention when they are free to range far in the wild.

"Such fieldwork is time-consuming, difficult and potentially dangerous," said researcher Marion Valeix, an ecologist at the University of Oxford in England and the French National Center for Scientific Research.

Scientists have had two ideas regarding why large mammalian carnivores depart a hunting ground. In the "unsuccessful hunt" hypothesis, predators hunt everything they can and then move on. In the alternate "patch disturbance" hypothesis, hunters leave after a successful kill to give remaining prey time to lower their guard — allowing the predators to return and blindside them. [Lions Attack Humans When Full Moon Wanes]

To see which strategy lions adopted, researchers followed the movements of eight African lions wearing global positioning system collars and ranging over about 2,700 square miles (7,000 square kilometers) in Hwange National Park in Zimbabwe.

Scientists matched the whereabouts of these big cats with 164 lion kills tracked down between 2005 and 2007. They found that after 87 percent of kills, the lions traveled at least three miles (five kilometers) or more, suggesting they were departing the scenes of their crimes.

"We showed the need for these animals to rotate their hunting between several hunting grounds — for example, waterholes in the Hwange ecosystem," Valeix told LiveScience. "This has implications regarding the configuration and size of lion home range and needs to be taken into account in the design of small conservation reserves."

Most studies focusing on large carnivores have considered them and large herbivores to be rather static variables.

"The most important implication of our findings is that they make a strong case for the crucial need to consider the behavior of large carnivores and large herbivores in a dynamic framework — lions continuously adjust to the behavior of their prey, which continuously adjust to the whereabouts of their predators."

In the future, the scientists plan to study both the behavior of predator and prey at the same time. They detailed their new findings in the August issue of the journal American Naturalist.

Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.

View the original article here

Humanity Again Ready to Make Giant Leaps into Space (ContributorNetwork)

Yahoo! News asked its readers and contributors to share their memories of the space shuttle program as it nears its end in July. Below is a story from a contributor.

[Your Voice: Sign up with the Yahoo! Contributor Network to share your thoughts.]

Intellectually, I am certain that it is time to retire the space shuttles from active service. We need to focus on the future instead of continuing to fly outdated vehicles into orbit. Emotionally, however, I have to say I have mixed feelings about the end of the space shuttle era.

[Related: Former NASA Chief of Staff Explains Why It's Time to Retire the Space Shuttle]

I remember the sense of wonder and excitement that I felt when a classmate in grammar school, knowing my interest in the space program, handed me the latest edition of Scholastic Magazine that featured and article about a planned reusable space shuttle in development by NASA. By the popular demand of thousands of Star Trek fans, the article said, NASA had to change the name of one of the early test shuttles to Enterprise.

The idea of a reusable launch vehicle that could glide to a runway landing seemed to me at the time to bring us one giant leap closer to making space travel a reality for the average person. Today, as the last space shuttle flight prepares to launch, that vision is even closer to reality. George Whitesides, President and CEO of Virgin Galactic told me he expects to be sending paying passengers to the edge of space next year.

I also remember watching the space shuttle Challenger as it seemed to disappear in forked trail of smoke. As I watched, I hoped that the smoke was caused by the jettisoning of malfunctioning booster rockets and that the shuttle itself would reappear and perhaps proceed to an emergency landing. Unfortunately, that wasn't the case and seven brave souls lost their lives on January 28, 1986.

[Related: Why Do So Many Remember Exactly Where They Were When the Challenger Exploded?]

The return to space after Challenger demonstrated that we, as a nation, could overcome adversity, learn from our mistakes, and push forward toward our goals. It also taught me that where much is at stake, one must use an abundance of care to make sure that things go the way one expects them to go.

[Related: Space Shuttle Rocket Scientist Discusses the Return to Space Effort]

Moving forward after the space shuttle, my hope is that we can develop safer and more cost-efficient launch and recovery vehicles, freeing resources for those grander goals that represent the next steps in our journey. With private companies beginning to find profit in space travel, we are once again ready to take one more giant leap into a future of nearly limitless possibilities.

[Related: Three Big Goals for NASA to Inspire a New Generations of Students]

Follow @Space_Matterson Twitter or 'like' the Space Matters Fan Page on Facebook for more of this author's space-related writing.

Brad Sylvester writes about the space program for the Yahoo! Contributor Network. Watching the Apollo missions through the static on a small black and white television sparked a lifelong interest in the space sciences for him. Since then, he has spent 40 years watching improvements in the technologies of space travel and our understanding of the universe unfold.

View the original article here

Exploded Star's Guts Shining Bright Again, Photo Shows (SPACE.com)

The glowing entrails of an exploding star, thought to have faded over time, now appear to be lighting up again, a new Hubble Space Telescope photo reveals.

NASA released the new Hubble image of the well-known star explosion, called Supernova 1987A, today (June 10). The photo shows the closest supernova explosion witnessed in almost 400 years. This has allowed astronomers to study it in unprecedented detail as the outburst evolves.

In the latest study of Supernova 1987A a team of astronomers announced that the debris from the explosion that had faded over the years is brightening. This suggests that the star explosion, which is located 165,000 light-years away in the Large Magellanic Cloud (a close neighbor of our own Milky Way galaxy),  is turning into a so-called supernova remnant. [See Hubble's new photo of Supernova 1987A]

The research is detailed in the June 9 edition of the journal Nature.

Supernovas typically transition into remnants when the exploded material starts to fade, but the brightness increases due to interactions between the debris cloud and surrounding gas. This cosmic shift is usually difficult for astronomers to study, but due to the relatively close proximity of the Large Magellanic Cloud, astronomers have been able to make detailed observations of Supernova 1987A periodically from 1994 to 2009.

"Supernova 1987A has become the youngest supernova remnant visible to us," said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "It's only possible to see this brightening because SN 1987A is so close and Hubble has such sharp vision."

Kirshner leads a long-term study of SN 1987A using the Hubble Space Telescope. Since its launch in 1990, Hubble has provided a continuous record of the changes in the supernova.

In the new Hubble image, SN 1987A is surrounded by a ring of material that blew off the star thousands of years before it exploded. The ring extends about one light-year (about 6 trillion miles or 9.5 trillion km) across. Inside that ring, the star's guts are rushing outward in an expanding debris cloud.

Most of the light from the supernova comes from radioactive decay of elements that were created in the explosion. This light fades over time, but the brightening of SN 1987A's debris suggests that a new power source is lighting it.

The debris of 1987A is beginning to impact the surrounding ring, which is creating powerful shock waves that produce X-rays that can be observed by NASA's Chandra X-ray Observatory. Those X-rays are illuminating the supernova debris and the heated shock waves are making it glow. This same process powers well-known supernova remnants in our own galaxy, like Cassiopeia A.

Furthermore, since SN 1987A is still young, astronomers can study the remnants of the explosion to decode its history.

Eventually, that history will be lost when the bulk of the expanding stellar debris impacts the surrounding ring and shreds it, researchers said. But, until then, SN 1987A offers astronomers the opportunity to watch as a supernova changes, they added.

Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

View the original article here