Earthquakes are one of most powerful, and sometimes most devastating, forces in nature. Scientists have devised a magnitude system to describe how the power of an earthquake increases. The great Tohuku earthquake in Japan in March 2011, for example, was a magnitude 9. The earthquake that rattled Washington D.C. and the U.S. east coast in August 2011 was a magnitude 5.8. What’s the difference? What does the earthquake magnitude system really mean? The animation below – from oceanographer Nathan Becker at the Pacific Tsunami Warning Center – can help you understand it.

Each earthquake magnitude is 33 times more powerful than the one before. So each jump in magnitude means a lot!

A magnitude-8.0 earthquake is 33 times stronger than a magnitude-7.0 earthquake.

A magnitude-9.0 earthquake is 1,089 (33 x 33) times more powerful than a 7.0.

Bottom line: Each jump in earthquake magnitude represents 33 times more energy release than the magnitude before. So each jump in magnitude means a lot! This animation oceanographer Nathan Becker at the Pacific Tsunami Warning Center can help you picture it.

Will Japan’s big quake in 2011 lead to more earthquake predictability?

Poster for the movie Men in Black 3 from Columbia Pictures. The movie is scheduled for release Friday, May 25, 2012. These guys are always saving the world from aliens who want to conquer, eat or destroy us.

Astronomer Jill Tarter – who stepped down earlier this week as director of the SETI Institute – said today (May 24, 2012) that she disagrees with those who depict extraterrestrials as angry warriors ready to enslave us, or eat us. In a press release from the SETI Institute, announcing their June 2012 SETIcon, Tarter said:

While Sir Stephen Hawking warned that alien life might try to conquer or colonize Earth, I respectfully disagree. If aliens were able to visit Earth that would mean they would have technological capabilities sophisticated enough not to need slaves, food, or other planets. If aliens were to come here it would be simply to explore.

Considering the age of the universe, we probably wouldn’t be their first extraterrestrial encounter, either.

She pointed to the bumper crop of summer 2012 alien movies, including Men in Black III, Prometheus and Battleship, as:

… great entertainment and metaphors for our own fears, but we should not consider them harbingers of alien visitation.

Jill Tarter, who stepped down as SETI Institute director this week, says any aliens who come here will be aiming to explore, not conquer. Photo credit: SETI

1951 movie The Day the Earth Stood Still. This movie depicts wise aliens who tell earthlings they must live peacefully or be destroyed as a danger to other planets.

She said those who favor the idea of angry aliens will have a chance to defend their vision at SETIcon, a public event sponsored by the SETI Institute. The Institute is known for its science-based search for radio signals that would betray the existence of intelligent beings on distant worlds. SETIcon will take place June 22 through 24 in Silicon Valley, California. Tickets are available now. Click here for more.

Bottom line: Former director of the SETI Institute, Jill Tarter, says she does not believe extraterrestrials who come to Earth will be looking to do us harm. Instead, she says, they’ll be here to explore. Tarter says those who stand behind the concept of angry aliens will have a chance to debate with friendly alien folk at SETIcon this summer. SETIcon will take place June 22 through 24, 2012 at the Santa Clara Hyatt Hotel, and will feature a celebrity banquet honoring Jill Tarter.

Jill Tarter to step down as SETI director

Why does the moon seem to change its shape every night?

The answer is the moon is a world in space, just as Earth is. Like Earth, it’s always half illuminated by the sun. In other words, the round globe of the moon has a day side and a night side. From our earthly vantage point, as the moon orbits around Earth, we see varying fractions of its day and night sides. These are the changing phases of the moon.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

Photo credit: Glass House

Waxing Crescent
First Quarter
Waxing Gibbous
Full Moon
Waning Gibbous
Last Quarter
Waning Crescent
New Moon

… and here are the names of all the full moons.

One key to understanding moon phases is to think about the whereabouts of the sun. After all, it’s the sun that’s illuminating and creating the day side of the moon. Moon phases depend on the sun. They depend on where the moon is with respect to the sun in space.

Another key to understanding moon phases is to remember that, like the sun and all the planets and stars, the moon rises in the east and sets in the west each and every day. It has to. The rising and setting of all celestial objects is due to Earth’s continuous spin beneath the sky.

Also, remember that the moon takes about a month (one “month”) to orbit the Earth. Although the moon rises in the east and sets in the west each day (due to Earth’s spin), it’s also moving on the sky’s dome each day due to its own motion in orbit around Earth. The moon’s orbital motion can be detected in front of the stars from one night to the next. It’s as though the moon is moving on the inside of a circle of 360 degrees. Thus the moon moves about 12 degrees each day.

The moon’s orbital motion is toward the east. Each day, as the moon moves another 12 degrees toward the east on the sky’s dome, Earth has to rotate a little longer to bring you around to where the moon is in space. Thus the moon rises, on average, about 50 minutes later each day. The later and later rising time of the moon causes our companion world to appear in a different part of the sky at each nightfall for about two weeks. Then, in the couple of weeks after full moon, you’ll find the moon rising later and later at night.

The study, funded by the National Institutes of Health, appears online ahead of print today in Molecular Cell and is scheduled for the July 13 print issue.

For decades, the scientific community has known that inflammation, accelerated aging and cancer are somehow intertwined, but the connection between them has remained largely a mystery, Dr. Schneider said. What was known, due in part to past studies by Schneider and his team, was that a gene called AUF1 controls inflammation by turning off the inflammatory response to stop the onset of septic shock. But this finding, while significant, did not explain a connection to accelerated aging and cancer.

When the researchers deleted the AUF1 gene, accelerated aging occurred, so they continued to focus their research efforts on the gene. Now, more than a decade in the making, the mystery surrounding the connection between inflammation, advanced aging and cancer is finally being unraveled.

The current study reveals that AUF1, a family of four related genes, not only controls the inflammatory response, but also maintains the integrity of chromosomes by activating the enzyme telomerase to repair the ends of chromosomes, thereby simultaneously reducing inflammation, preventing rapid aging and the development of cancer, Dr. Schneider explained.

“AUF1 is a medical and scientific trinity,” Dr. Schneider said. “Nature has designed a way to simultaneously turn off harmful inflammation and repair our chromosomes, thereby suppressing aging at the cellular level and in the whole animal.”

With this new information, Dr. Schneider and colleagues are examining human populations for specific types of genetic alterations in the AUF1 gene that are associated with the co-development of certain immune diseases, increased rates of aging and higher cancer incidence in individuals to determine exactly how the alterations manifest and present themselves clinically.

Republished with permission from NYU Langone Medical Center.

Fires have been burning in the Gila National Forest in New Mexico since May 16, 2012. Residents in southwestern New Mexico could see smoke from the fires billowing in their sky yesterday (May 23).

Map of New Mexico, with Gila National Forest in green, via Rocky Mountain Maps

As of yesterday, two fires in the national forest have merged and are now at more than 22,000 acres. A public information officer with the Gila National Forest told the Silver City Sun News yesterday that both air support and fire crews are standing by, waiting for the winds to die down so they can begin to attack the growing blaze.

The photo on this page comes from our friend Jacqueline McNeese in New Mexico. She wrote on EarthSky’s Facebook page yesterday:

[The fire] is located about 75 miles northwest of where I live. I could see white smoke around 1:30 p.m., and by around 6 p.m. (when I took this photo), it just took over almost the whole sky. This is looking in the direction of the fire. You can see the smoke coming up in the lower left corner of the photo, where the point of origin is.

Fires in Gila National Forest are affecting the skies in all of southwestern New Mexico. This photo is from EarthSky Facebook friend Jacqueline McNeese on May 23, 2012. She said these are the true colors she saw in the clouds of smoke. Note the whiter smoke from the source of the fire, in the lower left of this photo.

Click here to expand image above

A precautionary evacuation has been issued for the summer community of Willow Creek, New Mexico. Lightning started at least one of the fires, according to news reports from May 23.

Yesterday’s Silver City Sun News had an excellent story on the New Mexico fires, if you want to learn more.

Bottom line: Two fires in the Gila National Forest in New Mexico merged yesterday (May 23, 2012). There are now about 22,000 acres burning. Smoke from the fires is affecting all of southwestern New Mexico, according to news reports. Air support and fire crews are standing by, waiting for the winds to die down.

On the evening of May 24, 2012, the waxing crescent moon shines close to Castor and Pollux, the two brightest stars in the constellation Gemini the Twins. The moon is waxing toward a lunar eclipse on June 4. Finally, don’t forget to watch the bright planet Venus, as it drops into the sun’s glare.

Gemini? Here’s your constellation

People often refer to Castor and Pollux as “The Twins” but they aren’t really twins at all. At a distance of about 34 light-years, Pollux is the closest giant star to our solar system. It’s one of the very few giant stars in our galaxy known to have a planet.

Castor is farther away, at 52 light-years. It looks like a single star to the eye, but it’s actually six stars in one, all revolving around one another in an intricate dance.

Pollux on left. Castor on right. See the contrast in their colors? Pollux is golden, and Castor is white. (Warren Wilson College)

With binoculars, you might be able to discern Castor and Pollux’s contrasting colors. Pollux looks orange, while Castor appears white. An orange star has a relatively low surface temperature, indicating that Pollux is in the autumn of its years. On the other hand, a more youthful star – like Castor – displays a white color, a sure sign of this star’s higher surface temperature.

Meanwhile, tonight’s moon is in a waxing crescent phase. It’ll continue to wax larger until full moon in early June. Mark your calendar: this June 2012 full moon will feature a partial lunar eclipse. It’ll be visible throughout the Americas and Asia.

When you’re finished looking at the moon, Castor and Pollux, be sure to notice the planet Venus, still the brightest light besides the moon after sunset. Over the coming week, Venus will drop noticeably into the sun’s glare prior to the June 5-6 Venus transit – last one in this century! Venus is so bright that you can see it very near the sunset. And a lovely sight it is. You’ll need an unobstructed horizon, but if you have one it’ll be fun to watch until this wondrous planet, which has given us so much enjoyment in recent months, as it finally leaves the evening sky. The image below shows Venus near last night’s moon. It’s from our friend May Tama in Japan.

Moon and Venus on May 23, 2012 from EarthSky Facebook friend May Tama in Okayama, Japan.

Click here to expand image above

Bottom line: On the evening of May 24, 2012, the waxing crescent moon shines close to Castor and Pollux, the two brightest stars in the constellation Gemini the Twins. Mark your calendar for the June 4 lunar eclipse. Watch the bright planet Venus drop into the sun’s glare as it leaves the evening sky.

Castor is the fainter of two Twin stars

Pollux: Brightest star of the Twins

Lunar eclipse: Americas before sunrise, Asia after sunset June 4

So report researchers publishing a paper this week in the journal Nature Geoscience.

The paper, “Seagrass Ecosystems as a Globally Significant Carbon Stock,” is the first global analysis of carbon stored in seagrasses.

The results demonstrate that coastal seagrass beds store up to 83,000 metric tons of carbon per square kilometer, mostly in the soils beneath them.

Dense seagrass meadows are a hallmark of the Florida Coastal Everglades LTER site. Image Credit: Florida Coastal Everglades LTER Site.

As a comparison, a typical terrestrial forest stores about 30,000 metric tons per square kilometer, most of which is in the form of wood.

The research also estimates that, although seagrass meadows occupy less than 0.2 percent of the world’s oceans, they are responsible for more than 10 percent of all carbon buried annually in the sea.

“Seagrasses only take up a small percentage of global coastal area, but this assessment shows that they’re a dynamic ecosystem for carbon transformation,” said James Fourqurean, the lead author of the paper and a scientist at Florida International University and the National Science Foundation’s (NSF) Florida Coastal Everglades Long-Term Ecological Research (LTER) site.

The Florida Coastal Everglades LTER site is one of 26 such NSF LTER sites around the world in ecosystems from forests to tundra, coral reefs to barrier islands.

“Seagrasses have the unique ability to continue to store carbon in their roots and soil in coastal seas,” said Fourqurean. “We found places where seagrass beds have been storing carbon for thousands of years.”

The research was led by Fourqurean in partnership with scientists at the Spanish High Council for Scientific Investigation, the Oceans Institute at the University of Western Australia, Bangor University in the United Kingdom, the University of Southern Denmark, the Hellenic Center for Marine Research in Greece, Aarhus University in Denmark and the University of Virginia.

Seagrass meadows, the researchers found, store ninety percent of their carbon in the soil–and continue to build on it for centuries.

In the Mediterranean, the geographic region with the greatest concentration of carbon found in the study, seagrass meadows store carbon in deposits many meters deep.

Seagrasses are among the world’s most threatened ecosystems. Some 29 percent of all historic seagrass meadows have been destroyed, mainly due to dredging and degradation of water quality. At least 1.5 percent of Earth’s seagrass meadows are lost every year.

The study estimates that emissions from destruction of seagrass meadows can potentially emit up to 25 percent as much carbon as those from terrestrial deforestation.

Scientists take samples of seagrass beds at NSF's Florida Coastal Everglades LTER site. Image Credit: NSF Florida Coastal Everglades LTER Site.

“One remarkable thing about seagrass meadows is that, if restored, they can effectively and rapidly sequester carbon and reestablish lost carbon sinks,” said paper co-author Karen McGlathery, a scientist at the University of Virginia and NSF’s Virginia Coast Reserve LTER site.

The Virginia Coast Reserve and Florida Coastal Everglades LTER sites are known for their extensive seagrass beds.

Seagrasses have long been recognized for their many ecosystem benefits: they filter sediment from the oceans; protect coastlines against floods and storms; and serve as habitats for fish and other marine life.

The new results, say the scientists, emphasize that conserving and restoring seagrass meadows may reduce greenhouse gas emissions and increase carbon stores–while delivering important “ecosystem services” to coastal communities.

The research is part of the Blue Carbon Initiative, a collaborative effort of Conservation International, the International Union for Conservation of Nature, and the Intergovernmental Oceanographic Commission of UNESCO.

Republished with permission from the National Science Foundation.

A new map of the human brain provides a clearer picture of how different areas of our brain are physically connected and how these connections relate to basic brain function.

The University of Georgia researchers and identified 358 landmarks throughout the brain related to memory, vision, language, arousal regulation and many other fundamental bodily operations. Their findings were published in the April, 2012 issue of Cerebral Cortex.

Diffusion tensor imaging showing fibrous connections in the brain. Image courtesy UGA News Service

The landmarks were discovered using diffusion tensor imaging, a sophisticated neuroimaging technique that allows scientists to visualize nerve fiber connections throughout the brain. Unlike many other neuroimaging studies, their map does not focus only on one section of the brain but rather the whole cerebral cortex.

Tianming Liu, assistant professor of computer science in the University of Georgia Franklin College of Arts and Sciences, and his team examined hundreds of healthy young adults to establish the landmarks, which they call ‘dense individualized and common connectivity-based cortical landmarks,’ or DICCCOL.

After extensive testing and comparison, the team determined that these nodes are present in every normal brain, meaning they can be used as a basis of comparison for those with damaged brain tissue or altered brain function.

Now the researchers plan to test their brain map by comparing healthy brains with those of children whose brains were damaged by exposure to cocaine while in the womb.

Prenatal cocaine exposure, or PCE, can cause serious damage to brain networks. Because of this, analysis of the damage provides the team with an excellent opportunity to evaluate the usefulness of their map.

After comparing the PCE brains to those of healthy individuals, they hope to determine the segments of the brain responsible for physical or mental disabilities observed in children exposed to cocaine. Liu said:

The PCE brain is disrupted in a systematic way; the whole brain is wrongly wired. We want to test our map in one of the worst cases, and then we will know if it will work in other cases.

Once the robustness of their map is established, Liu and his team hope that it may prove useful in the evaluation of many other brain disorders, such as Alzheimer’s disease, Parkinson’s disease or stroke.

With this map, researchers hope to create a next-generation brain atlas that will be an alternative option to the atlas created by German anatomist Korbinian Brodmann more than 100 years ago, which is still commonly used in clinical and research settings.

Bottom line: University of Georgia researchers have developed a new map that provides a clearer picture of how different areas of the brain are physically connected and how these connections relate to basic brain function. The researchers identified 358 landmarks throughout the brain related to memory, vision, language, arousal regulation and many other fundamental bodily operations.

Read more from the the UGA News Service

Astrophysicist Neil deGrasse Tyson is director of the Hayden Planetarium in New York, and a beloved science communicator. In this video, he talks about the power and beauty of science as a human activity. The video is part of BigThink’s Humanizing Technology series. Listen to what Tyson has to say.

Last August, it was announced that Tyson will host a new sequel to Carl Sagan’s Cosmos: A Personal Voyage television series. Wonder how that’s going … that’s something I would like to see.

Bottom line: Neil deGrasse Tyson, video, science. Enough said.

Neil deGrasse Tyson on how the Pluto debate began

Neil deGrasse Tyson selected as EarthSky Science Communicator of the Year

The moon still shines in the vicinity of the planet Venus after sunset this Wednesday evening, May 23, 2012, as shown on our chart above. But the moon and Venus were paired most closely for the month on May 22. The moon and Venus – the brightest and second-brightest orbs of nighttime, respectively – pop out low in the west almost immediately after sunset tonight as seen from around the globe.

Moon and Venus on May 22, 2012 as seen in Normany, France by EarthSky Facebook friend Mohamed Laaifat Photography. Thank you, Mohamed.

Click here to expand image above

As people watched from around the world last night, the moon moved higher in the sky, going from below Venus as seen from the Middle East and Europe to side by side with it as seen from the U.S. West Coast. Tonight’s moon will be above Venus. Why this difference? Because the moon is moving in its orbit around Earth. No matter where you are on Earth, be sure to catch these shining beauties shortly after the sun goes down tonight.

Moon and Venus on May 22, 2012 as seen shining over the YMCA in New Albany, Indiana. Photo via EarthSky Facebook friend Duke Marsh. Thank you, Duke.

Click here to expand image above

The moon and Venus will follow the sun below the horizon by nightfall or early evening tonight. As seen from mid-northern latitudes, Venus sets about 100 minutes after the sun tonight and 40 minutes after sundown by the month’s end. For middle latitudes in the Southern Hemisphere, Venus sets about an hour after the sun tonight and tapers down to less than one-half hour after sunset by the month’s end.

Moon and Venus on May 22, 2012 as seen from Los Angeles. See how the moon was below Venus as seen from France (photo at top), but higher as seen from Indiana (second photo from top), and side by side with Venus as seen in this photo from Los Angeles? What you're seeing is the moon's motion in orbit around Earth. Photo via friend Peter Rodney Breaux. Thank you, Peter.

Click here to expand image above

As you might guess from those diminishing setting times, Venus is about to disappear in the sun’s glare.

This is the moon. See how the darkened portion glows faintly? That glow is called earthshine. It's light reflected from Earth's day side. Photo credit: Robbo-Man

If you looked at Venus through a telescope tonight, you'd see it in a crescent phase - much like the crescent moon. EarthSky Facebook friend Alan Murta took this serene photo of a crescent Venus in mid-May 2012. Thank you, Alan.

Because Venus lies inside of the Earth’s orbit, this world exhibits the full range of phases – much like our moon. In fact, the rest of May 2012 presents an especially good time to observe the phases of Venus through the telescope. Like the moon, Venus shows a slender crescent phase tonight. You might even be able to tell with your binoculars that Venus is something other than perfectly round.

Tonight, Venus appears about six percent illuminated in sunshine as seen from Earth. But this world is now waning, or showing us less and less of its day side. Venus will shrink to one percent illumination as seen from Earth by the end of May 2012. Venus will pass between the Earth and sun on June 5-6, 2012. Right now, Venus is headed for that event – preparing to pass between the Earth and sun on June 5-6 – and thus the distance between our two worlds is getting smaller. As a result, as seen from Earth, the crescent of Venus will wane in phase – yet become lengthier – in the coming weeks.

Starting tonight, watch as the moon and Venus part company in the May 2012 evening sky. In other words, for the next two weeks, note the positions of the moon and Venus as they come out after sunset. Venus will be sinking westward (toward the sunset point on the horizon) while the moon will be moving eastward (toward the sunrise point on the horizon). Thus the distance between the moon and Venus on our sky’s dome will be increasing.

And remember … Venus is now waning toward new phase while the moon is waxing toward full. At full moon on June 4, 2012, there will be a partial eclipse of the moon. And as Venus goes between the Earth and sun on June 5-6, 2012, this world will move as a dark dot in front the sun in what astronomers call a transit of Venus. There are at least two lunar and two solar eclipses every year. But this will be the last transit of Venus in this century.

Partial lunar eclipse for the Americas before sunrise June 4

Transit of Venus for North America on afternoon of June 5

When can you see earthshine on crescent moon?

Bottom line: On the evening of May 23, 2012, you can still see the moon in the vicinity of Venus, although the moon isn’t as close to Venus as it was last night. Through a telescope, both the moon and Venus would show you a crescent phase this evening.