Extinction-Level Superflares May Blast Earth's Nearest Exoplanet Proxima b

The recent discovery of a planet around the star closest to Earth's sun has raised hopes that life might exist around the sun's nearest neighbor, but researchers now find that this world might frequently experience extinction-level "superflares" from its star.

In August, scientists revealed the existence of an alien world around Proxima Centauri, a red dwarf star more than 600 times dimmer than the sun that lies just 4.2 light-years from Earth's solar system. This exoplanet, known as Proxima b, could be rocky and about the size of Earth. It also lies in its star's "habitable zone," the area around the star warm enough for the planet to potentially host liquid water on its surface. Since there is life virtually wherever there is water on Earth, being positioned in the habitable zone would raise the chance that Proxima b is home to life as it is known on Earth.

However, life likely needs more than just warmth and water to survive. Past research has found that many exoplanets are subject to superflares from their host stars, which can be up to thousands of times more powerful than ones seen so far from the sun. These massive flares could scour life from planets, especially those close to their stars, like Proxima b, which orbits Proxima Centauri at a distance one-tenth that between Mercury and the sun. 

To find out what effects flares might have on exoplanets, study author Dimitra Atri, a research scientist at the Blue Marble Space Institute of Science in Seattle, ran computer simulations modeling the interactions of planetary atmospheres with protons released during flares. These simulations included a wide range of flare strengths, planetary atmospheric thicknesses, orbital distances from stars and planetary magnetic field strengths, all factors that can influence how much radiation the surface of an exoplanet might receive.

Atri found that if Proxima b had an atmosphere and magnetic field like Earth's, superflares would not have any significant effect on the planet's biosphere. However, if Proxima b's atmosphere is slightly thinner, or its magnetic field is much weaker, the alien world would likely receive "extinction-level" doses of radiation from superflares, Atri discovered.

"I would say that it is too premature to call Proxima b habitable," Atri told Space.com. "There are many factors that would decide whether such a planet can sustain a biosphere. More data will help clarify the situation."

Prior work found that red dwarf stars such as Proxima Centauri, also known as M stars, constitute up to 70 percent of the stars in the cosmos, making them potentially key places to search for life. Because M stars are dim, the habitable zones of red dwarfs lie near these cold stars, often closer than the distance of Mercury from the sun. These findings suggest that superflares might pose a major threat to life on worlds in red dwarf habitable zones.

"Here is how I think about this — the weather in Fukushima [Japan] right now is in the mid-50s [Fahrenheit, or about 13 degrees Celsius], a bit chilly but a good temperature to spend time there," Atri said, referring to the site of a nuclear power plant disaster in 2011. "However the radiation dose there is too high, which would make living there too risky. The same is true with 'habitable' planets around M stars. They might have an optimum temperature, but stellar flares would produce very high radiation doses at regular intervals.

"One important aspect of this work is highlighting the critical importance of having a significant planetary magnetic field and good atmospheric shielding," Atri said. "With these two factors, even the most extreme stellar flares will not have much impact on a primitive biosphere."

Atri did note that previous research has found that some microbes on Earth can withstand very high doses of radiation, and that life on other worlds might also be radiation-resistant. "I am working with some experimentalists to reproduce such high radiation doses in a lab and see how different microbes respond," Atri said. "I think that would tell us a lot about potential life on planets such as Proxima b."

The new research appeared online on Sept. 30 in the journal Monthly Notices of the Royal Astronomical Society.

World's Oldest Wild Breeding Bird Is Expecting Her 41st Chick

Forget about the stork — it's the albatross that should be in charge of baby delivery. That's because the world's oldest wild breeding bird mother, a 66-year-old albatross named Wisdom, is incubating another egg, likely her 41st one, experts say.

Wisdom's new chick is unexpected; many albatrosses don't breed for two consecutive years, and Wisdom had a chick last year. Rather, most lay an egg one year and then take a break the next, instead investing their time and energy into molting their feathers, said researchers at the Midway Atoll National Wildlife Refuge and Battle of Midway National Memorial, located about 1,400 miles (2,250 kilometers) northwest of Hawaii.

Having healthy feathers is important because albatrosses spend almost 90 percent of their time flying, often covering thousands of miles as they search for food in the north Pacific Ocean, the researchers said. 

For whatever reason, Wisdom chose to lay an egg this year. The last time researchers saw the famous mom, she was sitting on her egg, waiting for the return of her mate, Akeakamai (a Hawaiian word that means "a love of wisdom, scholar"). Albatrosses often tag-team, with one parent incubating the egg while the other goes out to sea to hunt for food.

Every year, the duo returns to the wildlife refuge at Midway Atoll, an albatross hotspot.

Kristina McOmber, the refuge's biology program volunteer crew leader, discovered the expecting bird on Dec. 3. McOmber spotted Wisdom thanks to the bird's bright-red leg band placed there by scientists. Akeakamai was seen by the nest on Nov. 23, refuge volunteers said.

"I find it impressive that not only has Wisdom returned for over six decades as the oldest living, breeding bird in the wild, but also that biologists here on Midway have been keeping records that have allowed us to keep track of her over the years," Charlie Pelizza, the U.S. Fish and Wildlife Service's acting project leader for Midway Atoll Refuge and Memorial, said in a statement. "The staff was abuzz with the news that Wisdom was back and incubating. It's amazing what a bit of good news can do to brighten the day."

Biologist Chandler Robbins first banded Wisdom in 1956. Robbins, who is now 98, has kept abreast of Wisdom's travels over the years — an estimated 3 million miles (5 million km) in her lifetime — and heralded in the nine chicks she's laid since 2006, including Kūkini, who hatched in February 2016.

Wisdom may be a celebrity, but she's not a prima donna. Instead, she shares the National Wildlife Refuge with about 70 percent of the world's Laysan albatross (Phoebastria immutabilis) population, and almost 40 percent of the world's black-footed albatrosses (Phoebastria nigripes). The short-tailed albatross (Phoebastria albatrus), which the International Union for Conservation of Nature classifies as a vulnerable species, also occasionally nests on the Sand and Eastern islands within the refuge.

The birds typically arrive at the refuge in late October, and they number in the hundreds of thousands by the end of November, the biologists said.

World's Oldest Wild Breeding Bird Is Expecting Her 41st Chick

Forget about the stork — it's the albatross that should be in charge of baby delivery. That's because the world's oldest wild breeding bird mother, a 66-year-old albatross named Wisdom, is incubating another egg, likely her 41st one, experts say.

Wisdom's new chick is unexpected; many albatrosses don't breed for two consecutive years, and Wisdom had a chick last year. Rather, most lay an egg one year and then take a break the next, instead investing their time and energy into molting their feathers, said researchers at the Midway Atoll National Wildlife Refuge and Battle of Midway National Memorial, located about 1,400 miles (2,250 kilometers) northwest of Hawaii.

Having healthy feathers is important because albatrosses spend almost 90 percent of their time flying, often covering thousands of miles as they search for food in the north Pacific Ocean, the researchers said. 

For whatever reason, Wisdom chose to lay an egg this year. The last time researchers saw the famous mom, she was sitting on her egg, waiting for the return of her mate, Akeakamai (a Hawaiian word that means "a love of wisdom, scholar"). Albatrosses often tag-team, with one parent incubating the egg while the other goes out to sea to hunt for food.

Every year, the duo returns to the wildlife refuge at Midway Atoll, an albatross hotspot.

Kristina McOmber, the refuge's biology program volunteer crew leader, discovered the expecting bird on Dec. 3. McOmber spotted Wisdom thanks to the bird's bright-red leg band placed there by scientists. Akeakamai was seen by the nest on Nov. 23, refuge volunteers said.

"I find it impressive that not only has Wisdom returned for over six decades as the oldest living, breeding bird in the wild, but also that biologists here on Midway have been keeping records that have allowed us to keep track of her over the years," Charlie Pelizza, the U.S. Fish and Wildlife Service's acting project leader for Midway Atoll Refuge and Memorial, said in a statement. "The staff was abuzz with the news that Wisdom was back and incubating. It's amazing what a bit of good news can do to brighten the day."

Biologist Chandler Robbins first banded Wisdom in 1956. Robbins, who is now 98, has kept abreast of Wisdom's travels over the years — an estimated 3 million miles (5 million km) in her lifetime — and heralded in the nine chicks she's laid since 2006, including Kūkini, who hatched in February 2016.

Wisdom may be a celebrity, but she's not a prima donna. Instead, she shares the National Wildlife Refuge with about 70 percent of the world's Laysan albatross (Phoebastria immutabilis) population, and almost 40 percent of the world's black-footed albatrosses (Phoebastria nigripes). The short-tailed albatross (Phoebastria albatrus), which the International Union for Conservation of Nature classifies as a vulnerable species, also occasionally nests on the Sand and Eastern islands within the refuge.

The birds typically arrive at the refuge in late October, and they number in the hundreds of thousands by the end of November, the biologists said.

What Doomed Franklin's Polar Expedition? Thumbnail Holds Clue

For 170 years, scientists, historians and amateur sleuths alike have been trying to figure out what led to the demise of the Franklin Expedition, one of the deadliest disasters in polar exploration, which left all 129 crew members dead in the Canadian Arctic.

Now, a fingernail may hold clues about the fate of these men.

Researchers were able to reconstruct some information about the health and diet of one of Sir John Franklin's men in the weeks before his death, based on chemicals stored in his fingernail. Their study, published Dec. 6 in the Journal of Archaeological Science: Reports, offers further evidence against the theory that lead poisoning played a role in the expedition's fateful end.

Franklin's lost voyage

On behalf of the British Royal Navy, Franklin set out in 1845 with two ships, the HMS Erebus and the HMS Terror, in search of a northwest passage that would connect the Atlantic and Pacific oceans. The expedition became trapped in ice at Beechey Island in September 1846. Franklin died in June 1847.

According to the last written record from the crew, the ships were deserted in April 1848, as the surviving men left on foot to attempt to reach a trading post.

Search parties have collected scattered artifacts in the Arctic. (The shipwrecks of the Erebus and Terror were discovered only in the last few years.) And the graves of some of Franklin's men have been found. Most of the expedition's records, including their illness logs, have been lost, so mystery surrounds the final months, but they were likely desperate times. Inuit witness testimonies and more recent studies have suggested that some of Franklin's starving men resorted to cannibalism.

In the 1980s, scientists found high lead levels in thebones of crewmembers who were exhumed from their graves on Beechey Island. A common theory was that the men likely suffered from lead poisoning from metal in their food tins or in their drinking water system. While lead poisoning may not have been enough to kill Franklin and his crew, it could have exacerbated the effects of scurvy and starvation, and its neurological symptoms could have made the men delirious and mentally impaired.

Zinc deficiency to blame?

In a new study, Jennie Christensen, atoxicologist at TrichAnalytics in British Columbia, Canada, and her colleagues looked at a thumbnail and a big toenail from John Hartnell, one of the crewmembers who was buried on Beechey Island during the first stranded winter. The researchers were able to document how his exposure to different metals changed on a weekly basis. They concluded that Hartnell had lead concentrations within the normal range for healthy adults, and that his lead levels only spiked during his final weeks before his death, when his bones were breaking down and releasing stored-up lead into his system.

Christensen and her colleagues also found another potential culprit for Hartnell's declining health: a chronic zinc deficiency, perhaps related to a lack of meat in his diet.

A lack of zinc may have caused symptoms like emotional instability, depression and diarrhea, and it might have suppressed Hartnell's immune system, increasing his vulnerability to tuberculosis and pneumonia —the diseases that eventually killed him, the researchers wrote.

"Given Hartnell's nail zinc concentration pattern, it is probable that the tinned food was not appreciably zinc-rich and/or fresh arctic meat was not available to supplement the crew's diet," Christensen and her colleagues wrote. "While these speculations are based on only a single crewman, Hartnell's nail suggests other men on the Franklin Expedition may have shared a similar fate."

The new study builds on other recent research that suggests lead poisoning wasn't a major factor in the failure of Franklin's expedition. A 2014 study published in the journal Polar Record found that the lead levels of the crewmembers might be considered high today but were consistent with the wider 19th-century population. Another 2013 paper, published in the journal Applied Physics A , showed that the crew likely ingested lead throughout their lives, and there was no spike in lead ingestion during the expedition.

No Need to Delay Getting Pregnant After Miscarriage, Study Suggests

A new study suggests that becoming pregnant again soon after a miscarriage is no more risky for the mom or the fetus than waiting six months to conceive.

The new research contradicts the current World Health Organization advice on the subject, which suggests that a six-month wait might be beneficial for the baby. However, that advice was based on a single study. The new research, a statistical evaluation of data from 10 earlier studies on the topic, finds no additional risks for women who wait less than six months to become pregnant again after a miscarriage, and even finds that some risks may be lower with shorter intervals.

"Women who get pregnant after less than six months between the pregnancy and the loss should not be worried about adverse pregnancy outcomes, and if nothing else actually they should be encouraged," said Enrique Schisterman, a senior investigator in epidemiology at the National Institute of Child Health and Human Development. Schisterman was not involved in the new study, known as a meta-analysis, although he did co-author one of the earlier studies that the new study re-evaluated. 

Pregnancy intervals

Researchers have found that conceiving shortly after a full-term pregnancy can raise the risk of complications, such as premature birth and low birth weight (around 18 and 23 months between pregnancies was least risky, according to a 2006 meta-analysis published in the journal JAMA). But there was very little data on pregnancy spacing after miscarriage, and the study upon which the WHO based its recommendations was based in Latin America and couldn't distinguish between spontaneous losses and abortions.

In the new analysis, researchers led by Sohinee Bhattacharya at the University of Aberdeen combed the literature for studies that compared outcomes for women who conceived either within six months of a miscarriage, or more than six months after. They found a total of 10 studies in which researchers looked at pregnancies with those timeframes and recorded data on the complications, such as having another miscarriage (defined as a loss of the fetus before 24 weeks gestation), suffering a stillbirth (a loss after 24 weeks gestation), having a premature birth, having a baby born with low birth weight and having preeclampsia, a condition in which a pregnant woman's blood pressure increases to dangerous levels. [9 Conditions Pregnancy May Bring]

Pooling the data from the studies and re-evaluating the statistics, the researchers found no evidence that getting pregnant soon after a miscarriage is dangerous. The data on stillbirths and preeclampsia showed no difference in the risk of these conditions regardless of pregnancy spacing. And some complications appeared less likely with quicker conceptions: The rate of having another miscarriage with a pregnancy spacing of less than six months was only 82 percent of the rate of having another miscarriage with a spacing of more than six months. The risk of preterm birth was also less for shorter intervals, too, at 79 percent of the rate seen in women with intervals longer than six months.

The researchers also found that for several of the birth complications, the Latin American study that was used as the basis for the WHO recommendations was an outlier. For example, when that study was included in the analysis, the statistics showed no difference between a spacing of less than six months versus a spacing more than six months in the risk for having a low-birth-weight baby (defined as a term baby weighing less than 5.5 pounds, or 2,500 grams). But when that one study was excluded, the risk of having a low-birth-weight baby appeared to be lower for more closely spaced pregnancies, at 74 percent the rate of longer-spaced pregnancies.

Try when ready

Undergoing full-term pregnancies back-to-back may diminish a mother's supply of folate, a B vitamin important for the developing nervous system, Schisterman said. But a pregnancy lost before full-term will likely not diminish a woman's folate supply for future pregnancies, he said. Meanwhile, waiting longer to conceive, especially for women later in their fertile years, might increase the risk of complications.

The lack of information on how far along the pregnancies were when miscarriages occurred is one limitation of the new study, Schisterman said. It may be that early miscarriages do not tax a pregnant woman's reserves, while a later loss may make a short spacing riskier.

"I think we need a little bit more data on the different underlying reasons for a pregnancy loss and see what the optimal interval is," Schisterman said.

The new research also looked at when women conceived — not when they actually started trying. But couples can only control when they start trying for a baby, Schisterman said, and not the timing of the actual pregnancy. Some of the seeming beneficial effects of a short pregnancy interval may be because the women who became pregnant again sooner were more fertile, Bhattacharya and her team wrote, and thus both became pregnant with more ease and had fewer complications in those pregnancies. [7 Ways Pregnant Women Affect Babies]

Nevertheless, the study might inform how doctors discuss the risks and benefits of future pregnancies with their patients.

"There is now ample evidence to suggest that delaying a pregnancy following a miscarriage is not beneficial and unless there are specific reasons for delay couples should be advised to try for another pregnancy as soon as they feel ready," Bhattacharya and her colleagues wrote.

The researchers published their findings Nov. 17 in the journal Human Reproduction Update.

ISIS May Face War-Crime Charges for Destruction of Historic Sites

As a combined Iraqi-Kurdish force fights its way into Mosul, the last major Iraqi city held by the Islamic State group (also known as Daesh, ISIS or ISIL), there have been reports that some ISIS fighters have chosen to surrender rather than fight to the death.

Photos released by Agence France-Presse (AFP) show the surrender of a few individuals, which the AFP called "suspected ISIL jihadists," near the ancient Assyrian city of Nimrud (which was dynamited and bulldozed by ISIS) and Mar Behnam (a Christian monastery that was heavily damaged and vandalized by ISIS). It's unknown if any of the individuals who surrendered are responsible for the destruction at the two historical sites.

Additional reports from multiple media outlets suggest that fighters (or alleged fighters) are surrendering in Mosul, where the Islamic State group has destroyed a number of historical sites, including the Tomb of Jonah, a site revered by both Muslims and Christians. Again, it is not known if any of those who surrendered took part in those acts.

Because international law forbids the destruction of heritage sites, those who surrendered could face charges for war crimes, experts say. The United Nations Educational, Scientific and Cultural Organization (UNESCO) lists areas as World Heritage Sites for having special cultural or physical significance.

"These destructions may amount to a war crime, and UNESCO will do everything in its power to document the damage so that these attacks do not go unpunished," said Irina Bokova, director-general of UNESCO, said in a statement released on Nov 25, after Nimrud was recaptured.

During the Islamic State group's campaign of destruction, the militant organization made several propaganda videos showing members destroying historical sites. Legal experts say those members may soon regret doing so.

"I'm confident that there will be trials for the destruction we've seen in the Middle East, and that the videos and photographs produced by ISIL to brag about their destruction will one day reappear in court as evidence against them," said Erin Thompson, a professor of art crime at the City University of New York.

International Criminal Court

It would not be the first time someone has been brought to trial on war-crime charges of destroying heritage sites. Ahmad al-Faqi al-Mahdi, who was a member of an al-Qaida-affiliated terrorist group, was brought to trial for his help in destroying parts of Timbuktu in Mali. He pleaded guilty and was sentenced in September 2016 to nine years in prison.

However, as several legal experts noted, there are many challenges in investigating and prosecuting captured Islamic State group members. For instance, Iraq is not a party to the Rome Treaty, a treaty negotiated in Rome which allows citizens of a country that signed the treaty to be brought to the International Criminal Court, located in The Hague, Netherlands, to face war-crime charges. [See Photos of Amazing UNESCO World Heritage Sites]

This obstacle is not insurmountable, legal experts noted. The United Nations Security Council can invoke what are known as "Chapter 7" powers that will allow the International Criminal Court to investigate and prosecute a war crime, regardless of whether a country has signed the treaty, said Tess Davis, executive director of the Antiquities Coalition, a group of archaeologists, lawyers, former government officials and other experts who advocate for measures to stop illegal antiquities trading. Davis said it is unknown whether the Security Council will invoke those powers.

If the U.N. Security Council were to invoke Chapter 7 powers, it would have to allocate the financial resources and logistics necessary for the International Criminal Court to investigate the cases and bring the individuals facing charges to trial, Davis added.

Hague Convention

Iraq is a party to the 1954 Hague Convention that protects heritage sites in times of war. That stipulation could be used to bring Islamic State group members who destroyed historical sites to justice. However, the trial may have to be held before a local Iraqi court or a U.N. tribunal, rather than the International Criminal Court, experts told Live Science.

"There are a variety of international conventions that protect cultural property in times of armed conflict and domestic laws that proscribe trespassing and vandalism," said Rick St. Hilaire, a lawyer with Red Arch Cultural Heritage Law & Policy Research. In addition to the Hague Convention, parts of the Geneva Convention also prohibit the destruction of historical sites.

"The question is not so much what laws are in place; the important question is whether there is political will to enforce the laws and whether there are appropriate resources to catch the perpetrators and collect the evidence needed to [convict] them," St. Hilaire said.

"Both Syria and Iraq are member states of the 1954 Hague Convention, meaning that they are responsible to criminally prosecute violators after resolution of a conflict," said Leila Amineddoleh, a cultural heritage lawyer who is a partner in the firm Amineddoleh & Associates LLC.

Amineddoleh noted that the U.N. may want to see whether Iraq and Syria can prosecute these cases. "In the case that nations cannot properly address these issues, international bodies may pursue looters. The U.N. may find it appropriate to seek and prosecute individuals responsible for vandalism and looting as crimes against humanity, potentially in conjunction with the International Criminal Court," Amineddoleh told Live Science.

However, given the multitude of crimes committed by the Islamic State group and the resources needed to prosecute them, Amineddoleh said she doesn't expect many cases involving the destruction of heritage sites to go to trial.

"Although there is precedent for prosecuting vandals for heritage destruction, it is unlikely that many of these cases will be brought to court," Amineddoleh said. "The resources involved in trying them are too expensive, and the international community will probably devote courts to justice after violent crimes and genocide, not the protection of property."