Great White Shark Filmed Breaching at Night -- A First

See a real footage of a great white shark hunting seals IN THE DARK!

First check out the video, then read the article to find out more:

Brian Handwerk
for National Geographic News

July 25, 2008

Although seals are a common meal for great white sharks, under the cover of darkness, one might expect the marine mammals to catch a break. Dramatic new footage, however, proves great whites sometimes fancy a midnight snack.

The video shows a 13-foot (4-meter) shark launching itself from the water to snare a seal at the surface—the first time such "breach feeding" has been documented at night.

The footage appears in Sharkville, which will air July 25 at 10 p.m. eastern time on the National Geographic Channel. (National Geographic News and the National Geographic Channel are both a part of the National Geographic Society.)

Welcome to "Sharkville"

South African marine biologist Ryan Johnson and his team got the shot in a section of South Africa's Mosselbaai (Mossel Bay) dubbed Sharkville, where a large population of great whites lives nearly year-round not far from a popular beach.

The sharks don't bother the bay's human bathers. But a colony of some 5,000 seals on a small island just a half mile (800 meters) from shore isn't so lucky.

Johnson, founder of the South African Marine Predator Lab, first discovered that Mosselbaai's great whites breach the water's surface to feed at night through a lot of hard work and a bit of luck.

In 2005 he'd been following about 165 feet (50 meters) behind a shark fitted with an acoustic tracking tag for 103 straight hours.

"It was nighttime, so we didn't expect a lot of action," he remembered.

"And 30 meters [100 feet] from us, it erupts from the water with a seal in its mouth and sits there chewing on it," he said. "There was enough moonlight to see this going on."

Johnson said the event forced his team to reconsider how the sharks feed.

Read more by clicking here

VIDEO: Stuck Polar Bears Eating Birds

The guillemot, a seabird that depends on ice, is losing its habitat and falling prey to polar bears desperate for food. Part of Wild Chronicles' Climate Connections series.

Can biofuels solve America's oil crunch?

ATLANTA, Georgia (CNN) -- A summer with budget-busting gasoline prices seems like the worst time to launch a cross-country road trip from California to Georgia, but this one is different: We're road-testing alternative fuel that might help reduce pollution and break the nation's reliance on foreign oil.

CNN.com producer Cody McCloy will drive this 1978 International Harvester Scout cross-country on biodiesel fuel.

The gasoline alternative is called biodiesel, and it's made from a mixture of diesel gasoline and vegetable oil, such as soy or corn. The vegetable oil is nontoxic and biodegradable.

Most diesel cars can run on it, and it can be found in more and more places around the country. Web developer Brian Hardy and I will begin our two-week journey from California's San Francisco Bay area to Atlanta, Georgia, on Monday at 9:40 a.m. on CNN.com Live.

During our road trip, we'll blog and report about what kind of mileage we're getting with biodiesel fuel and how easy it is to find places that sell it.

Biodiesel is just one of several biofuels powering more and more U.S. cars and trucks. Mesa, Arizona, for example, has switched its fleet of 1,000 municipal vehicles such as fire engines and street sweepers to biodiesel and other green fuels such as ethanol, and compressed natural gas. Watch for details on benefits of biodiesel fuel »

Some biofuels are less expensive per gallon than gasoline -- cutting the average cost of gas by 20 to 35 cents per gallon, according to the U.S. Department of Energy. An average American family can save up to $300 per year by using ethanol, according to the DOE Web site.

Biodiesel fuel, however, is not always cheaper than gasoline -- although it is made using renewable resources, such as grain or used cooking oil.

Atlanta-area biodiesel dealer Rob Del Bueno says -- if you really think about it -- it's amazing how something as simple as a gallon of fuel can move a heavy multi-ton vehicle down the road.

"We think fuel is expensive, but for what you get, the price that you pay at the pump is so insignificant to what's really going on."

But Department of Energy chemical engineer John Scahill warns that the price of petroleum -- now at about $125 per barrel -- will become "prohibitively expensive within our lifetime."

About $333 billion exited the United States in 2007 due to the purchase of oil, according to Scahill, illustrating the high cost of importing foreign energy. Biofuel is produced and sold in the United States -- which keeps money from those transactions circulating inside the U.S. economy.

"About 140 billion gallons of gasoline per year are used for transportation in the United States," said Scahill, "and we can save about a third of that if we maximize our use of biofuels."

Our biodiesel vehicle is a 1978 International Harvester Scout that we purchased in San Jose, California, just for this adventure. We trust this all-terrain classic will serve us well on our trip. CNN.com users can vote on possible destinations at the bottom of the American Road Trips special report here.

We'll talk to experts about emerging energy sources that offer alternatives to oil including wind power, hydro-electric and solar.

And we'll offer tips on how to make your summer road trip more environmentally friendly and easier on your pocketbook.

We'll be testing GPS navigation gear and other cool gadgets to see how they work during a real road trip. But because it's a road trip, we'll also be camping and enjoying some of the most spectacular sites in the Southwest and Southeastern United States. And we'll be asking CNN.com users to suggest destinations and to vote on where we travel.

VIDEO: Giant River Stingrays Found

After an exhaustive search, an explorer finds one of the elusive rays—perhaps the largest freshwater fish—near Bangkok. And then it gives birth.



Think that is cool? Check out another ray video I found:

Click here to view it

Solar Eclipse: How it Works

Check out this video about how a solar eclipse works.

View this eclipse on August 1, 2008!

From Garbage to Gas Tank: Trash as Biofuel

July 23, 2008 -- Within the next two years, some of us may be running our cars on trash.

Two companies -- INEOS bio of Lyndhurst, U.K., and Coskata of Warrenville, Ill. -- claim to be within reach of producing ethanol from garbage on a commercial scale.

INEOS bio announced this week that they plan to produce commercial quantities of waste-derived ethanol within two years. Coskata plans to have a commercial demonstration facility by mid-2009.

The companies use similar processes to turn municipal waste into ethanol. The first step is gasification, in which the waste is heated with limited oxygen to create carbon monoxide and hydrogen.

"It's a very different process from incineration, where you completely combust in excess air," which results in carbon dioxide and water, said INEOS bio's Graham Rice. "We're trying to go halfway and produce carbon monoxide, which still has a lot of chemical energy."

The carbon monoxide and hydrogen mixture is then fed to bacteria, which convert the mixture into ethanol. The ethanol is then purified and blended with fuel.

"It's a process which can take any form of carbon waste," Rice said. Coskata's Wes Bolsen agreed. "It might be trash. It might be tires. It might be biomass."

Importantly, none of these starting materials is used for food, so this process sidesteps concerns over diverting food crops like corn into biofuel production.

The process also uses less than half the water needed to make ethanol from corn, Bolsen said. It uses as little as a quarter of the water that might be required to make ethanol from waste biomass or grass crops by digesting the plants' cellulose and converting it to ethanol -- seen as the next generation in biofuel production.

"The analysis we've done is that the greenhouse gas emissions we'd expect would be a 90 percent reduction compared to petrol [gasoline]," Rice added.

INEOS bio's commercial facility in Fayetteville, Ark., will use green household waste, including compostable household clippings, food waste, mixed waste paper and cardboard. The company estimates that biodegradable household waste in the United States alone could make five billion gallons a year of ethanol, which is more than half of the current U.S. ethanol demand of nine billion gallons.

Coskata plans to run five different materials through their commercial demonstration plant: wood chips, sugar cane waste, municipal waste, natural gas and a potential energy crop such as switchgrass.

"We're looking at one dollar a gallon production cost," Bolsen said, "which competes directly with [the cost of ethanol from] Brazilian sugarcane, and we can do it here in the U.S."

"Wherever there are people, wastes are generated," Rice said. "What I'd like to see is every community converting its waste into renewable transport fuel."

---

Related Links:

How Stuff Works: Bioethanol

Planet Green

Hurricane Dolly, Busy July Suggest Stormy Months Ahead

Willie Drye

for National Geographic News

July 23, 2008

As a strengthening Hurricane Dolly heads for landfall today near the Texas-Mexico border, some meteorologists see indications that the rest of this year's hurricane season could be very active.

As of noon eastern time today, the center of Hurricane Dolly was about 35 miles (48 kilometers) northeast of Brownsville, Texas.
The storm's strongest winds were blowing at about 96 to 110 miles (154 to 177 kilometers). That makes Dolly a Category 2 storm on the Saffir-Simpson scale, which rates hurricanes from 1 to 5 based on the damage they are likely to cause.
Dolly's winds could increase before the storm comes ashore around 1 p.m. eastern time, said Christopher Juckins, a meteorologist at the National Hurricane Center in Miami, Florida.
The storm is over warm water in the Gulf of Mexico—which could allow it to intensify—and there are no upper-level winds that would inhibit its development.
(Create your own interactive hurricane.)
Busy Month
Experts believe Hurricane Dolly's impact will be minimal, because it likely will go ashore in an area that is not heavily populated. Other July hurricanes in past years have been much more powerful than Dolly.
Still, the formation of Hurricane Dolly—as well as Hurricane Bertha and tropical storm Cristobal earlier this month—make July 2008 unusual, meteorologists say.
On July 19, Bertha, Cristobal, and Dolly were all active tropical weather systems, noted meteorologist Jeff Masters of Ann Arbor, Michigan, founder of the commercial forecasting Web site Weather Underground.
That's the first time three named systems have been active on the same day since the practice of naming hurricanes began in 1950, he said.

Poop Power

July 24, 2008 -- Researchers have identified a climate-energy win-win, but it may put them in deep doo-doo.

That's what happens when you study poop for a living. Michael Webber and Amanda Cuéllar of the University of Texas at Austin estimate that digesting all of the nation's livestock manure to produce methane to burn for energy could supply more than 2 percent of the country's electricity needs.

Meanwhile, the process would avoid the greenhouse gas emissions created by burning the equivalent amount of coal, and it would prevent the release of the super-potent greenhouse gases methane and nitrous oxide released by normal manure degradation, allowing for a double-whammy of greenhouse gas reduction.

The combined savings could reduce U.S. greenhouse gas emissions from electricity by about 4 percent.

"We wanted to look at what would happen if we took all the manure in the nation, which is currently an environmental liability, and turned it into a commodity as a source of energy," Webber said. The pair's work is published today in Environmental Research Letters.

Livestock in the United States unload more than a billion tons of manure each year, most of which ends up in lagoons or other outdoor locations where it decomposes, emitting methane and nitrous oxide, greenhouse gases 21 and 310 times more potent at warming than CO2, respectively.

The proposed approach would send the manure to anaerobic digesters where microorganisms would produce biogas rich in methane that could be captured and burned for energy, releasing the less-potent greenhouse gas CO2. The remaining solids could be used for fertilizer.

This approach would reduce other problems associated with manure ponds, including odor, air pollution, and water pollution from runoff or groundwater contamination, Webber said.

Digesters exist in the United States, and many more are used in Europe. But this is the first time anyone has studied the total potential of biogas production in the United States, he added. "The numbers are big enough that they're worth paying attention to."

"This isn't new technology. It's not hard to implement," he added. "It's decades-old technology that's ready to go right now. We just haven't done it. We don't have incentives."

But now, the rising cost of energy and increasing drive to reduce greenhouse gases and generate renewable energy make this a better time than ever to consider this approach, Webber said.

"There are a lot of biofeedstocks that are receiving a lot of criticism," Webber told Discovery News. "This one seems controversy-free. It's a waste stream right now. It doesn't fall into the trap of competing with food."

"They paint a very rosy picture of biogas potential by considering all the animals in the country," said Christopher Weber of Carnegie Mellon University in Pittsburgh, Pa., who has studied greenhouse gas emissions from livestock.

Webber agrees that not all animals are kept in conditions where it would be easy to collect the manure. Large feedlots would be the best starting point. But his analysis provides an upper limit for what might be possible, he said.

Meat, especially red meat, has received recent attention as a less "green" diet choice than vegetables or fish because of the greenhouse gas emissions associated with its production, including from manure. Reducing the greenhouse gas emissions from manure improves the calculation, but it does not even the playing field, Weber said.

"It would do nothing about the carbon dioxide and nitrous oxide in the production of the grain to feed the animals, which is another large chunk of the greenhouse gases associated with red meat production," he said. Cows would continue to burp methane as part of their digestion, which is the largest source of methane in beef production.

"All in all, for grain-fed beef, I would think manure is responsible for a total of 20 percent of the life cycle emissions or so; a good start but certainly not enough to make beef on par with vegetables or fish in greenhouse gas production."

---

Related Links:

How Stuff Works: Why do cows produce methane?

Info on Biogas

Planet Green

Discovery Earth Live

July 22, 2008 -- Just as humans tune into individual radio stations, an unusual Chinese frog can shift its hearing from one frequency to another in order to selectively choose what it hears, according to a paper published in this week's Proceedings of the National Academy of Sciences.

The frog, Odorrana tormota, is the only known animal in the world that can manipulate its hearing system to select particular frequencies. Humans appear to possess a modicum of control, but our system is slow compared to that of the frog and we cannot, with precision, tune our ears to match sounds.

The rare amphibian likely evolved its hearing talent out of necessity, since its environment is so noisy.

"Their calling sites are on the steep banks of a fast-flowing body of water -- the Tao Hua Creek (at Huangshan Hot Springs in central China)," co-author Albert Feng told Discovery News.

Feng, a professor of molecular and integrative physiology at the University of Illinois at Urbana-Champaign, added that the site is especially noisy after spring showers. He pointed out that humans often cannot hear well over heavy rains either.

"We pretty much have to shout at one another," he said.

The frog doesn't shout, but it instead sings like a bird either in audible chirp-like frequencies or by emitting very high-pitched ultrasonic sounds.

Curious as to how the amphibian could hear these different vocalizations, Feng and his team analyzed the frog's hearing system, which wasn't too challenging since the frog's eardrum is completely transparent.

The scientists used a laser to measure the eardrum's vibration, and noticed that while it could respond to both audible and ultrasonic sounds, sometimes the eardrum's sensitivity to ultrasonic noise mysteriously disappeared.

Further investigation determined the frog actively opens and closes two narrow channels known as the Eustachian tubes, which connect the pharynx (part of the neck and throat) to the left and right middle ears. When open, the tubes couple the frog's left and right ears, making them sensitive to audible sounds from all directions. When closed, their ability to pick up ultrasonic frequencies kicks in.

"We said, 'Woah! This is bizarre!'" Feng recalled. "In all textbooks on sound communication and hearing in frogs, it is plainly stated that the Eustachian tubes are permanently open!"

The ability to tune into specific frequencies at will isn't the frog's only claim to animal fame. It also possesses recessed ears instead of ones that, like those of most other creatures, are located on the body's surface. It additionally can localize sound with astonishing precision.

With an error of less than 1 percent, males of this species leap directly toward calling, wooing females. This level of accuracy has never before been observed in frogs.

"On the one hand, I am surprised that any frog can open and close the Eustachian tubes," Carl Gerhardt, professor of biological sciences at the University of Missouri, told Discovery News.

"But on the other hand, I am not too surprised that this frog does it because it is also the first to be shown to have ultrasonic hearing and calls with ultrasonic components."

The frog's unique hearing system is already being used as a model for "intelligent" hearing aids that can spatially separate sounds, process them the way that human brains do, and boost sound signals of interest, such as differentiating background noise from that of a desired conversation.

---

Related Links:

Animal Planet

How Stuff Works: Are frogs on the brink of extinction?

VIDEO: Green Dream Machines

What is the new trend in car development? One thing they all have in common is that are all green.




Check out a video of these new "green" cars here

Space Debris: A Picture is Worth 1,000 words!!!

July 17, 2008

Earth's Ringed Wonder

As a writer, I’ve never warmed to the expression “a picture is worth 1,000 words,” but I found one that left me speechless:

Kudos to the European Space Agency for finding a way to graphically unmask the cloud of debris circling Earth. Like many problems, this one grew slowly over time.

It started when the first man-made object reached orbit, the Soviet satellite Sputnik on Oct. 4, 1957. Since then, more than 6,000 have followed. Fewer than 15 percent are operational today.

The dead satellites aren’t the main problem. It’s the ones that have blown up and the fragments of rocket bodies that booted them into orbit. In all, about 10,000 pieces of debris are being tracked by ground radar and optical telescopes, but it is the estimated 50,000 items too small for detection that are making the highways in space a hazard to travel.

The speed is what kills. Flecks of paint just .33 mm in size have cracked windows on the space shuttle. That’s what happens when objects are traveling 17 times faster than machine gun bullets.

China became the world’s most egregious contributor to space debris when it intentionally blew up a defunct weather satellite last year in a weapons test (so much for international treaties), boosting the amount of detectable space junk by 22 percent.

Tack it on to the long list of topics under discussion at the annual COSPAR (Committee on Space Research) meeting in Montreal this week. And while we're at it, perhaps we should think about adding Earth to the list of planets sporting rings:

PHOTO IN THE NEWS: Volcano Spews Ash 50,000 Feet High

July 15, 2008—This is one time when you'd want the window seat.

Kelly Reeves of Alaska Airlines snapped the above photo as a plane flew above an Aleutian Islands volcano on July 13, 2008, the day after its first violent eruption.
The July 12 explosion of the 3,500-foot (1,067-meter) Okmok Volcano on Umnak Island spewed ash and sulfur dioxide 50,000 feet (15,240 kilometers) high, and the materials have since formed into a large mass hovering above the North Pacific.
The new eruption is more intense than the volcano's past three major events in 1945, 1958, and 1997, according to a statement by the Alaska Volcano Observatory. This explosion is uniquely water-rich, due to the mixing of rising magma and shallow groundwater, the statement said.
(Read about another volcano that erupted in Alaska in 2006.)
Ten people who live on Umnak Island were evacuated, and nearby Unalaska Island has been covered with a light ashfall, Jennifer Adleman, a geologist with the Alaska Volcano Observatory, told Reuters news service.
"There have been reports of eye irritation and people being able to taste it, if you will," Adleman said. "Some folks have seen it on their windshields."
Observers predict lava will eventually spill from the caldera, and that activity will continue for several weeks and possibly longer.
—Christine Dell'Amore

Photograph by Kelly Reeves/Alaska Airlines/Alaska Volcano Observatory

Cat Nurses Baby Red Panda

A Tabby Cat nurses a baby red Panda at a zoo in Amsterdam.



Check out the video here

VIDEO: Kilauea Spews Lava Fountain

Hawaii's Kilauea volcano—which has been erupting for 24 years now—continues to spew lava during its latest active spurt from fissures far below the crater.



Check out the video here!

Photo: Yellowstone Geysers May Stop Erupting, Study Suggests

Matt Kaplan
for National Geographic News

July 9, 2008

Old Faithful may not be so faithful anymore.

A long-term study of Yellowstone National Park's iconic geysers suggests that dry spells caused by climate change are slowing—and may even stop—the geysers' clockwork-regular eruptions.
His team found that over their study period, geyser intervals got longer as the park went into a prolonged dry spell.
The two trends appear to be linked, but only over considerable periods of time.
"As the region went into a drier climate, all intervals got longer," Hurwitz said.
Surprisingly, on a monthly basis not all analyzed geysers responded similarly to precipitation patterns in the park, yet over years the geysers underwent the same trends, he added.
The scientists say that if climate change continues to dry the area out, the intervals between geyser eruptions could get longer and longer. Under extreme conditions, the displays could even cease completely.
Hot and Bothered
Between 1998 and 2006, researchers monitored the schedule of five of the park's geysers using temperature sensors.
The two best known geysers showed the most changes: The time between Old Faithful's eruptions shifted from an hour 15 minutes to an hour 31 minutes, while Daisy Geyser's interval shifted from an hour 40 minutes to two hours 50 minutes.
"Geysers are different from steam vents, mud pots, and hot springs—they have eruptions," said study leader Shaul Hurwitz at the U.S. Geological Survey in Menlo Park, California.
"We wanted to know if we could learn something about Yellowstone's hydrothermal system by analyzing the intervals between these eruptions."
While much remains unknown about how geysers respond to small changes in the environment, clear long-term trends are emerging, the researchers say.
The study appeared in the June issue of the journal Geology.
Steamy Situation
Yellowstone's most famous geysers, especially Old Faithful, are known for the regularity of their eruptions—it's a pattern solid enough for tourists to make plans around.
But geysers depend upon a unique combination of water supply, heat, and rock fractures, Hurwitz pointed out.
Even small earthquakes, slight variations in underground temperature, and tiny alterations in water availability can dramatically change the size and appearance of an eruption, and no one is exactly sure how. So Yellowstone's geysers are very susceptible to environmental changes like the increasing dry periods affecting Wyoming, Montana, and Idaho, Hurwitz said.
Michael Manga, a geologist at the University of California, Berkeley, said the new study may help solve the longstanding puzzle of how earthquakes affect geysers.
"This study shows that changing the ability of water to recharge the geyser affects eruptions," said Manga, who was not involved in the research. "Perhaps this too is how distant earthquakes affect eruptions—by changing the ability of surrounding water to recharge the geyser."
Ken Verosub, a geophysicist at the University of California, Davis, also was not involved with the study.
"While the effects of short-term climate fluctuations do not appear to be too significant, longer-term climate change looks like it can have a big effect on geysers," he said. "This could be bad news for tourism."

Tragedy inspires maker of military robots

TYNGSBOROUGH, Massachusetts (AP) -- The knock on Brian Hart's door came at 6 a.m. An Army colonel, a priest and a police officer had come to tell Hart and his wife that their 20-year-old son had been killed when his military vehicle was ambushed in Iraq.

One of Black-I Robotics' robotic vehicles.

Brian Hart didn't channel his grief quietly. Committed to "preventing the senseless from recurring," he railed against the military on his blog for shortcomings in supplying armor to soldiers. The one-time Republican teamed with liberal Sen. Edward Kennedy to tell Congress that the Pentagon was leaving soldiers ill-equipped.
And then Hart went beyond words to fight his cause. He became a defense contractor.
He founded a company that has developed rugged, relatively inexpensive robotic vehicles, resembling small dune buggies, to disable car bombs and roadside explosives before they detonate in hot spots like Iraq and Afghanistan.
Now, Hart has won over the military brass he so harshly criticizes. Three years after starting Black-I Robotics Inc., Hart and his four employees won a $728,000 contract from the Pentagon in June to further develop the "LandShark" robot.
Read more here

Smallest planet shrinks in size

[from BBC Science/Nature News]

The smallest planet in the Solar System has become even smaller, studies by the Messenger spacecraft have shown.

Data from a flyby of Mercury in January 2008 show the planet has contracted by more than one mile (1.5km) in diameter over its history.
Scientists believe the shrinkage is due to the planet's core slowly cooling.
Studies published in the journal Science show the same process also powers the planet's magnetic field, a topic long debated by scientists.
"Cooling of the planet's core not only fuelled the magnetic dynamo, it also led to contraction of the entire planet," said Principal Investigator Sean Solomon of the Carnegie Institution of Washington, US.
"And the data from the flyby indicate that the total contraction is at least one-third greater than we previously thought."
Active youth
The Messenger (Mercury Surface, Space Environment, Geochemistry and Ranging) spacecraft passed within 200km (125 miles) of Mercury earlier this year.
It was the first time the planet had been viewed up close since Mariner 10's third and final fly-by in March 1975.

A kidney-shaped volcanic vent surrounded by ejected material

The flyby was one of three to be made by the craft as it prepares to enter into orbit around the Solar System's smallest planet in 2011.
Just days after the pass, scientists revealed that they had found evidence of volcanic activity on the planet, previously hinted at by Mariner 10.
Further analysis of areas such as the Caloris basin, one of the Solar System's largest and youngest impact basins, found volcanic vents and evidence of "pyroclastic" debris blown from the volcano as it erupted.
Other areas contained circular structures with wrinkled edges, similar to structures seen on the Moon and Mars.
Scientists believe these are impact craters that have been filled with massive quantities of lava, possibly 2.7km (1.3miles) deep.
"That's a lot of lava," said Dr James Head of Brown University. "It shows the planet was really active in its early history."
Researchers believe the peak of activity could have been three to four billion years ago.
Core effects
Sensors, such as the Fast Imaging Plasma Spectrometer (FIPS), onboard the craft also revealed details of the planet's atmospheric composition.
FIPS recorded silicon, sodium and even water ions around Mercury. Ions are electrically charged atomic particles.
The scientists believe these were blasted from the surface of the planet by the solar wind, a stream of charged particles which buffets the Solar System.
Mercury's proximity to the Sun means it feels the full force of this wind, blasting atoms into space. Many of these are then trapped by the planet's magnetic field.
"The Mercury magnetosphere is full of many ionic species, both atomic and molecular," said Dr Thomas Zurbuchen of the University of Michigan.
This magnetosphere is created by the planet's core, which accounts for 60% of the planet's mass.
As well as influencing the space around the planet, the core has had an immense influence on surface features.
"The dominant tectonic landforms on Mercury, including areas imaged for the first time by Messenger, are features called lobate scarps, huge cliffs that mark the tops of crustal faults that formed during the contraction of the surrounding area," explained Dr Solomon.
"They tell us how important the cooling core has been to the evolution of the surface."