CAPE CANAVERAL, Fla. (AP) — Saturn's giant moon Titan may not have a vast underground ocean after all.
Titan instead may hold deep layers of ice and slush more akin to Earth’s polar seas, with pockets of melted water where life could possibly survive and even thrive, scientists reported Wednesday.
The team led by researchers at NASA's Jet Propulsion Laboratory challenged the decade-long assumption of a buried global ocean at Titan after taking a fresh look at observations made years ago by NASA’s Cassini spacecraft around Saturn.
They stress that no one has found any signs of life at Titan, the solar system’s second largest moon spanning 3,200 miles (5,150 kilometers) and brimming with lakes of liquid methane on its frosty surface.
But with the latest findings suggesting a slushy, near-melting environment, “there is strong justification for continued optimism regarding the potential for extraterrestrial life,” said the University of Washington’s Baptiste Journaux, who took part in the study published in the journal Nature.
As to what form of life that might be, possibly strictly microscopic, “nature has repeatedly demonstrated far greater creativity than the most imaginative scientists," he said in an email.
JPL’s Flavio Petricca, the lead author, said Titan’s ocean may have frozen in the past and is currently melting, or its hydrosphere might be evolving toward complete freezing.
Computer models suggest these layers of ice, slush and water extend to a depth of more than 340 miles (550 kilometers). The outer ice shell is thought to be about 100 miles (170 kilometers) deep, covering layers of slush and pools of water that could go down another 250 miles (400 kilometers). This water could be as warm as 68 degrees Fahrenheit (20 degrees Celsius).
Because Titan is tidally locked, the same side of the moon faces Saturn all the time, just like our own moon and Earth. Saturn’s gravitational pull is so intense that it deforms the moon’s surface, creating bulges as high as 30 feet (10 meters) when the two bodies are closest.
Through improved data processing, Petricca and his team managed to measure the timing between the peak gravitational tug and the rising of Titan’s surface. If the moon held a wet ocean, the effect would be immediate, Petricca said, but a 15-hour gap was detected, indicating an interior of slushy ice with pockets of liquid water. Computer modeling of Titan’s orientation in space supported their theory.
Sapienza University of Rome’s Luciano Iess, whose previous studies using Cassini data indicated a hidden ocean at Titan, is not convinced by the latest findings.
While “certainly intriguing and will stimulate renewed discussion ... at present, the available evidence looks certainly not sufficient to exclude Titan from the family of ocean worlds," Iess said in an email.
NASA’s planned Dragonfly mission — featuring a helicopter-type craft due to launch to Titan later this decade — is expected to provide more clarity on the moon’s innards. Journaux is part of that team.
Saturn leads the solar system’s moon inventory with 274. Jupiter’s moon Ganymede is just a little larger than Titan, with a possible underground ocean. Other suspected water worlds include Saturn’s Enceladus and Jupiter’s Europa, both of which are believed to have geysers of water erupting from their frozen crusts.
Launched in 1997, Cassini reached Saturn in 2004, orbiting the ringed planet and flying past its moons until deliberately plunging through Saturn’s atmosphere in 2017.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.
FILE - This image provided by NASA shows bright methane clouds drifting in the summer skies of Saturn's moon Titan, along with dark hydrocarbon lakes and seas clustered around the north pole, as seen from the Cassini spacecraft, June 9, 2017. (NASA/JPL-Caltech/Space Science Institute via AP, File)
FILE - This image made by the Cassini spacecraft and provided by NASA on March 12, 2006, shows two of Saturn's moons, the small Epimetheus and smog-enshrouded Titan, with Saturn's A and F rings stretching across the frame. (NASA via AP)
SIOUX FALLS, S.D. (AP) — Easter is around the corner, and it's time to start thinking about how to decorate your eggs.
Whether you're dying eggs for your table spread or planning to hide them for an egg hunt, it's important to follow food safety guidelines to minimize germs and maximize your egg quality.
Eggs are remarkably long lasting, so there needn't be a giant rush to eat them.
“Stores usually do turn over eggs pretty quickly, so the recommendations is you should consume eggs three to five weeks after you purchase them,” said Kara Lynch, food safety educator with Michigan State University Extension.
There is also a benefit in letting eggs age just a bit, as older eggs can be easier to peel. That's because eggs shrink over time within the shell, creating an air pocket between the egg and the shell.
Egg processors clean eggs before they reach store shelves, but it also is important to thoroughly cook eggs to reduce the risk of foodborne illness, especially salmonella. That bacteria lives naturally in the gastrointestinal and reproductive tracts of chickens, said Kimberly Baker, associate extension specialist at Clemson University.
To cook your eggs, place them in a saucepan, fill it with water and bring it to a boil. After that, put the lid on, turn the heat off and let it sit for about 12 minutes. Some also favor turning down the heat and simmering eggs.
You can vary the time in the hot water depending on a desire for harder boiled or slightly creamier eggs, but the yolk should be pretty solid to be safe. Boiling them for too long can risk creating green sulfur development on the outside of the yolk.
After that, Don Schaffner, food science department chair at Rutgers University, said there are two options.
You can run your eggs under cold water to reduce the temperature. From there, you can color them right away or place them back in the fridge until you're ready. Or, after you've boiled them, you can let them air dry until they've cooled.
The boiling process sanitizes the eggs, and as long as they are kept out of water, Schaffner said, they will remain safe to eat.
“You’ve boiled the egg, you’ve gotten rid of any bacteria that might be in the egg. And now you’ve air-cooled it, right? So it’s going to cool more slowly, it’s probably going to cook more,” he said. “But most importantly, you don’t have to worry about any bacteria from the water getting internalized into the egg.”
Either artificial or natural food dye is OK as long as the dye label says it's food grade. For those keeping track, the U.S. Food and Drug Administration has been updating its guidance and regulations regarding certain dyes.
And no, it's not a problem if the dye seeps through the shell.
“Eggs kind of naturally have their own abilities to absorb only so much,” Baker said.
As you're decorating the eggs and have the eggs outside, she suggested keeping your eggs in an ice bath, so they can stay at a cooler temperature while you're decorating.
Eggs should generally be kept at or below 40 degrees (4.4 degrees Celsius) to minimize the risk of contaminants.
Cooked eggs that weren't air-cooled should spend no more than two hours at room temperature. And that's cumulative, including the time spent decorating and the time spent hiding during the Easter egg hunt.
But if it's particularly warm, then that two-hour rule may be shortened to one hour, Lynch said.
Hard boiled eggs are generally good for about a week in the fridge.
Be careful with your eggs as you handle them.
One of the biggest concerns is making sure your eggs haven't cracked during an Easter egg hunt, making them vulnerable to contaminants. And once the egg has been hard boiled, there's no way to kill bacteria that get inside, Baker said.
“We don’t want to be putting them in the soil or in lawns where pets have gone to the bathroom,” she said.
Whether the eggs are hidden outdoors or in a corner of your home, you should rinse them in cool water before you peel them. And wash your hands, too, just in case the eggs have picked up something.
If the Easter egg hunt means your eggs will be at room temperature for longer than two hours, experts recommended using plastic eggs for the hunt instead of real ones to minimize food safety risk.
“If it’s an outdoor Easter egg hunt at any time, I would say go with the plastic eggs and be safe,” Baker said. “And use your dyed Easter eggs as your centerpiece on your table or your buffet, and enjoy them that way.”
FILE - Painted Easter eggs hang from an Easter Tree in Saalfeld, central Germany, March 30, 2018. (AP Photo/Jens Meyer, File)
