5 Revelations About Ceres That Are Blowing Scientists' Minds

Permanently shadowed regions capable of accumulating surface ice were identified in the northern hemisphere of Ceres using images taken by NASA’s Dawn mission combined with sophisticated computer modeling of illumination. Image credit: NASA/JPL-Caltech

The journal Science just published six significant papers about the dwarf planet Ceres. We pored over them to see what has planetary scientists so excited.

Ceres is the only dwarf planet in the asteroid belt, located between Mars and Jupiter. On June 30, the Dawn spacecraft over Ceres completed its prime mission, and NASA has since extended its mission through at least April 2017, at which time the vessel will possibly run out of hydrazine fuel. (Yesterday it moved to a higher orbit, where it will have less of Ceres's gravity dragging on it, and can thus conserve fuel.) Dawn's continuing mission will involve studying Ceres as the world reaches perihelion—that is, as it reaches its closest point to the sun its elliptical orbit.

Since Dawn's arrival at Ceres last year—after first spending a year orbiting Vesta, a minor planet in the asteroid belt—the dwarf planet has proven captivating beyond anyone's expectation. Its mysterious white spots garnered unprecedented public interest. NASA even launched a poll for people to guess what they might be. (Those who suspected alien beacon were, sadly, incorrect; scientists believe the correct answer is salt.)

The spots are but a tiny part of the scientific bonanza delivered by Dawn, however, and 16 months after its arrival at Ceres, scientists have finally been able to get a grip on the libraries of data being returned from the spacecraft. Here are some of their key findings.

1. IT HAS ICE VOLCANOES.

Ahuna Mons is an isolated mountain on the surface of Ceres that is, according to one paper published today, "distinct in its size, shape, and morphology." The mountain's formation, scientists suspect, is as such: cryomagma (ice lava!) erupted to the surface of Ceres, causing the development and spreading of an cryovolcanic (ice volcano!) dome. This occurred much in the same manner as a volcano forms on Earth. As material erupted, it followed the grooves and fractures already present on the surface of Ceres. The ice volcano's formation and composition suggest that the surface of Ceres is warmer than that of icy moons, and within Ceres, there is or was some long-term heat source. Moreover, other "topographic rises" on Ceres might well "share a common formation process and imply that volcanic activity occurred over an extended period." Differing structures and shapes of said rises might be attributed to changes in flow and ascent over time.

2. IT SHARES UNEXPECTED COMMONALITIES WITH MARS AND OUR MOON.

Dawn's Framing Camera has mapped Ceres, and the revealed geology is a scientific bonanza, giving scientists clues necessary to piece together the history and geologic activities of the mysterious world. Debra Buczkowski is one of those scientists. She is the lead author of one of the papers published today. She tells mental_floss that what surprised her most about Ceres was the discovery of "floor-fractured craters," or craters with shallow floors cut by fractures of various shape.

"These are features found on the Moon and Mars," she said, "where they are thought to form due to magma upwelling beneath impact craters, pushing their floors upward and causing them to fracture." Such features were not predicted on Ceres. As to the implications, Buczkowski says, "Finding these features on Ceres means that there was at some point in time magmatic processes occurring on Ceres." She notes that evidence of magmatism (along with the identification of Ahuna Mons as a cryovolcanic feature) indicates that Ceres was at some point in time geologically active, "although we have yet to find evidence that it is still an active body."

Another of the Science papers found a relatively even composition (but unequal abundance) of clay-like phyllosilicate minerals—which need water to form—on Ceres' surface. This suggests that "widespread and extensive aqueous alteration processes have affected the dwarf planet at some point in its history."    

3. CERES ALSO HAS ICE ON ITS SURFACE

Planetary scientists have long believed that the mantle of Ceres is rich in water ice (and perhaps water). According to another paper published today, data from the visible and infrared mapping spectrometer (VIR) identified "without ambiguity" H2O absorption bands in a young crater on Ceres called Oxo: "These bands are most likely due to surface materials," the scientists say. In other words, in at least this 10-kilometer crater, there is water ice on the surface of Ceres—and not billion-year-old ice that probably tastes awful, but the young, fresh stuff. At Oxo's latitude, water ice could at best last a few hundred years before disappearing, and would be undetectable in tens of years because of dust in the ice, which would quickly become "the dominant material within the optical thickness (a few micrometers at most)."

So where did this ice come from? The authors of the paper suggest four possible origins: exposure of internal ice due to a surface impact (i.e. giant rock smashing into Ceres); re-condensed water vapor that originated from within Ceres, much in the way the nuclei of comets release water vapor; a water-rich rock crashed into Ceres; or water molecules formed due to "implantation of protons" by solar winds. (This happens on our Moon, too.)

4. … BUT IT MAY BE ROCKY ICE (OR ICY ROCK).

Craters tell an astonishing amount about celestial objects, from their age and composition to their history and internal processes. Ceres is heavily cratered and yet lacks craters larger than 300 kilometers, which is a bit unexpected. Moreover, the suspected composition of Ceres suggests that many of those craters should have "relaxed" over time, which by and large has not happened. This leads scientists to believe that the crust of Ceres possesses less ice than was expected or might be thicker than once thought. Rather than possessing a solid ice shell just below the surface, Ceres might have more of a rocky-ice (or icy-rock) shell.

5. IT MAY HAVE AN EXOSPHERE.

An exosphere is the very outer limits of an atmosphere. (For reference, the Earth's exosphere begins around 300 kilometers beyond the altitude of the International Space Station.) It's where particles are gravitationally bound to an object but are very heavily influenced by the Sun. Before Dawn arrived at Ceres, instruments on the Hubble Space Telescope were unsuccessful in detecting an exosphere at the dwarf planet. Data returned by Dawn now tell a slightly different story. The Dawn spacecraft carries an instrument called the Gamma Ray and Neutron Detector (GRaND). On multiple orbits, GRaND detected bursts of energetic electrons. At those moments, scientists suspect that the weak atmosphere at Ceres was "ionized by the energetic particles in the solar wind, producing a bow shock as the solar wind was deflected," as the paper authors write. When the solar event stopped, ionization of the atmosphere ceased, and the exosphere vanished.

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10 Facts About the Appendix
Illustration by Mental Floss / Images: iStock
Illustration by Mental Floss / Images: iStock

Despite some 500 years of study, the appendix might be one of the least understood structures in the human body. Here's what we know about this mysterious organ.

1. THE ANCIENT EGYPTIANS CALLED IT THE "WORM" OF THE BOWEL.

The human appendix is small, tube-shaped, and squishy, giving ancient Egyptians, who encountered it when preparing bodies for funerary rites, the impression of a worm. Even today, some medical texts refer to the organ as vermiform—Latin for "worm-like."

2. THE APPENDIX SHOWS UP IN LEONARDO DA VINCI’S DRAWINGS.

The earliest description of a human appendix was written by the Renaissance physician-anatomist Jacopo Berengario da Carpi in 1521. But before that, Leonardo da Vinci is believed to drawn the first depiction of the organ in his anatomical drawings in 1492. Leonardo claimed to have dissected 30 human corpses in his effort to understand the way the body worked from mechanical and physiological perspectives.

3. IT'S ABOUT THE SIZE OF A PINKY FINGER.

The appendix is a small pouch connected to the cecum—the beginning of the large intestine in the lower right-hand corner of your abdomen. The cecum’s job is to receive undigested food from the small intestine, absorb fluids and salts that remain after food is digested, and mix them with mucus for easier elimination; according to Mohamad Abouzeid, M.D., assistant professor and attending surgeon at NYU Langone Medical Center, the cecum and appendix have similar tissue structures.

4. CHARLES DARWIN THOUGHT IT WAS A VESTIGIAL ORGAN …

The appendix has an ill-deserved reputation as a vestigial organ—meaning that it allegedly evolved without a detectable function—and we can blame Charles Darwin for that. In the mid-19th century, the appendix had been identified only in humans and great apes. Darwin thought that our earlier ancestors ate mostly plants, and thus needed a large cecum in which to break down the tough fibers. He hypothesized that over time, apes and humans evolved to eat a more varied and easier-to-digest diet, and the cecum shrank accordingly. The appendix itself, Darwin believed, emerged from the folds of the wizened cecum without its own special purpose.

5. … BUT THE APPENDIX PROBABLY EVOLVED TO HELP IMMUNE FUNCTION.

The proximity and tissue similarities between the cecum and appendix suggest that the latter plays a part in the digestive process. But there’s one noticeable difference in the appendix that you can see only under a microscope. “[The appendix] has a high concentration of the immune cells within its walls,” Abouzeid tells Mental Floss.

Recent research into the appendix's connection to the immune system has suggested a few theories. In a 2015 study in Nature Immunology, Australian researchers discovered that a type of immune cells called innate lymphoid cells (ILCs) proliferate in the appendix and seem to encourage the repopulation of symbiotic bacteria in the gut. This action may help the gut recover from infections, which tend to wipe out fluids, nutrients, and good bacteria.

For a 2013 study examining the evolutionary rationale for the appendix in mammal species, researchers at Midwestern University and Duke University Medical Center concluded that the organ evolved at least 32 times among different lineages, but not in response to dietary or environmental factors.

The same researchers analyzed 533 mammal species for a 2017 study and found that those with appendices had more lymphatic (immune) tissue in the cecum. That suggests that the nearby appendix could serve as "a secondary immune organ," the researchers said in a statement. "Lymphatic tissue can also stimulate growth of some types of beneficial gut bacteria, providing further evidence that the appendix may serve as a 'safe house' for helpful gut bacteria." This good bacteria may help to replenish healthy flora in the gut after infection or illness.

6. ABOUT 7 PERCENT OF AMERICANS WILL GET APPENDICITIS DURING THEIR LIFETIMES.

For such a tiny organ, the appendix gets infected easily. According to Abouzeid, appendicitis occurs when the appendix gets plugged by hardened feces (called a fecalith or appendicolith), too much mucus, or the buildup of immune cells after a viral or bacterial infection. In the United States, the lifetime risk of getting appendicitis is one in 15, and incidence in newly developed countries is rising. It's most common in young adults, and most dangerous in the elderly.

When infected, the appendix swells up as pus fills its interior cavity. It can grow several times larger than its average 3-inch size: One inflamed appendix removed from a British man in 2004 measured just over 8 inches, while another specimen, reported in 2007 in the Journal of Clinical Pathology, measured 8.6 inches. People with appendicitis might feel generalized pain around the bellybutton that localizes on the right side of the abdomen, and experience nausea or vomiting, fever, or body aches. Some people also get diarrhea.

7. APPENDECTOMIES ARE ALMOST 100 PERCENT EFFECTIVE FOR TREATING APPENDICITIS.

Treatment for appendicitis can go two ways: appendectomy, a.k.a. surgical removal of the appendix, or a first line of antibiotics to treat the underlying infection. Appendectomies are more than 99 percent effective against recurring infection, since the organ itself is removed. (There have been cases of "stump appendicitis," where an incompletely removed appendix becomes infected, which often require further surgery.)

Studies show that antibiotics produce about a 72 percent initial success rate. “However, if you follow these patients out for about a year, they often get recurrent appendicitis,” Abouzeid says. One 2017 study in the World Journal of Surgery followed 710 appendicitis patients for a year after antibiotic treatment and found a 26.5 percent recurrence rate for subsequent infections.

8. AN INFECTED APPENDIX DOESN’T ACTUALLY BURST.

You might imagine a ruptured appendix, known formally as a perforation, being akin to the "chestbuster" scene in Alien. Abouzeid says it's not quite that dramatic, though it can be dangerous. When the appendix gets clogged, pressure builds inside the cavity of the appendix, called the lumen. That chokes off blood supply to certain tissues. “The tissue dies off and falls apart, and you get perforation,” Abouzeid says. But rather than exploding, the organ leaks fluids that can infect other tissues.

A burst appendix is a medical emergency. Sometimes the body can contain the infection in an abscess, Abouzeid says, which may be identified through CT scans or X-rays and treated with IV antibiotics. But if the infection is left untreated, it can spread to other parts of the abdomen, a serious condition called peritonitis. At that point, the infection can become life-threatening.

9. SURGEONS CAN REMOVE AN APPENDIX THROUGH A TINY INCISION.

In 1894, Charles McBurney, a surgeon at New York's Roosevelt Hospital, popularized an open-cavity, muscle-splitting technique [PDF] to remove an infected appendix, which is now called an open appendectomy. Surgeons continued to use McBurney's method until the advent of laparoscopic surgery, a less invasive method in which the doctor makes small cuts in the patient's abdomen and threads a thin tube with a camera and surgical tools into the incisions. The appendix is removed through one of those incisions, which are usually less than an inch in length.

The first laparoscopic appendectomies were performed by German physician Kurt Semm in the early 1980s. Since then, laparoscopic appendectomies have become the standard treatment for uncomplicated appendicitis. For more serious infections, open appendectomies are still performed.

10. AN APPENDIX ONCE POSTPONED A ROYAL CORONATION.

When the future King Edward VII of Great Britain came down with appendicitis (or "perityphlitis," as it was called back then) in June 1902, mortality rates for the disease were as high as 26 percent. It was about two weeks before his scheduled coronation on June 26, 1902, and Edward resisted having an appendectomy, which was then a relatively new procedure. But surgeon and appendicitis expert Frederick Treves made clear that Edward would probably die without it. Treves drained Edward's infected abscess, without removing the organ, at Buckingham Palace; Edward recovered and was crowned on August 9, 1902.

11. THE WORLD'S LONGEST APPENDIX MEASURED MORE THAN 10 INCHES.

On August 26, 2006, during an autopsy at a Zagreb, Croatia hospital, surgeons obtained a 10.24-inch appendix from 72-year-old Safranco August. The deceased currently holds the Guinness World Record for "largest appendix removed."

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Science Has a Good Explanation For Why You Can't Resist That Doughnut
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Unless you’re one of those rare people who doesn’t like sweets, the lure of a glazed or powdered doughnut is often too powerful to resist. The next time you succumb to that second or third Boston cream, don’t blame it on weak willpower—blame it on your brain.

As the New Scientist reports, a Yale University study published in the journal Cell Metabolism provides new evidence that foods rich in both carbohydrates and fats fire up the brain’s reward center more than most foods. For the study, volunteers were shown pictures of carb-heavy foods (like candy), fatty foods (like cheese), and foods high in both (like doughnuts). They were then asked to bid money on the food they wanted to eat most, all while researchers measured their brain activity.

Not only were volunteers willing to pay more for doughnuts and similar foods, but foods high in carbs and fat also sparked far more activity in the striatum, the area of the brain where dopamine is released. (Chocolate is one of the foods most commonly associated with increases in dopamine, working in the same way as drugs like cocaine and amphetamines.)

Presented with these findings, researcher Dana Small theorized that the brain may have separate systems to assess fats and carbs. Modern junk foods that activate both systems at once may trigger a larger release of dopamine as a result.

This study doesn’t entirely explain why different people crave different foods, though. Much of it has to do with our habits and the foods we repeatedly gravitate towards when we want to feel happy or alleviate stress. Another study from 2015 found that certain treats associated with high levels of reward in the brain—like pizza, chocolate, chips, and cookies—were considered to be the most addictive foods (doughnuts didn’t make the top 20, though).

It's still possible to turn down foods that are bad for you, though. While many people try to improve their self-control, one of the most effective ways to avoid an undesired outcome is to remove the temptation completely. Free doughnuts in the break room? Stay far away.

[h/t New Scientist]

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