New zone could expand search for habitable planets

Researchers are suggesting a new way to expand the search for habitable planets that takes into account a zone not previously considered: the space between the star and what’s called soot line in planet-forming disks.

Worlds that form in this region—a disk of dust rotating around a central star from which planets may be built—could have surfaces rich in volatile carbon compounds quite different from Earth’s.

These planets would also be rich in organic carbon, but water poor, according to study lead author Ted Bergin, professor and chair of astronomy at the University of Michigan.

When we search for Earth-like planets, we are particularly interested not only in bodies that look like ours, but also in those that are formed by processes similar to ours.

Current models of rocky exoplanets are built using Earth-like atmospheric conditions and bulk composition, including the molecules essential for life that form from carbon-based building blocks and water. These models also focus on zones within planet-forming disks called ice lines, regions distant enough from the disk’s center star which mark where water or other key molecules transition from gas to solid phases.

Terrestrial worlds, like our planet, formed from solids. It has long been thought that Earth, which contains only approximately 0.1% water by mass, must have formed inside the water-ice line.

But that type of model may be too limited, Bergin says. To expand the search for habitable planets, Bergin and his research team suggest a new model that considers the soot line, a boundary closer to the solar system’s star.

Between this boundary and the star, organic compounds in solids sublimate out of the solid into gas. Considering this region would also encompass rocky planets that may have more carbon than Earth has, raising questions about what that means for habitability in these kinds of planets.

“It adds a new dimension in our search for habitability. It may be a negative dimension or it may be a positive dimension,” Bergin says. “It’s exciting because it leads to all kinds of endless possibilities.”

Why Earth has so little carbon

Just as Earth is poor in water, it is carbon poor as well, Bergin says. When forming, it likely received only 1 carbon atom per 100 available in planet-forming materials. Astronomers think the soot line explains why Earth has so little carbon.

If Earth’s building blocks formed inside the soot line, the temperature and solar radiation blasted the materials that would form the young planet, turning carbon-rich compounds into gas and limiting carbon in the solids that are supplied to the forming Earth.

The team’s model theorizes about the formation of other planets born in between the soot line and water-ice lines.

Such a world does not appear to exist in our solar system, but our solar system is not representative of most known planetary systems around other stars, Bergin says. These other planetary systems look completely different. Their planets are closer to the sun and are much larger, ranging in size from what are called super-Earths to mini-Neptunes, he says.

“These are either big rocks or small gas giants—that’s the most common type of planetary system. So maybe, within all those other solar systems out in the Milky Way galaxy, there exists a population of bodies that we haven’t recognized before that have much more carbon in their interiors. What are the consequences of that?” Bergin says. “What this means for habitability needs to be explored.”

Hazy habitable planets

In their study, the team models what happens when a silicate-rich world with 0.1% and 1% carbon by mass and a variable water content forms in the soot line region. They found that such a planet would develop a methane-rich atmosphere through a process called outgassing. In this circumstance, organic compounds in a silicate-rich planet produce a methane-rich atmosphere.

The presence of methane provides a fertile environment for the generation of hazes through interactions with stellar photons. This is analogous to the generation of hazes from methane in Titan in our own solar system.

“Planets that are born within this region, which exists in every planet-forming disk system, will release more volatile carbon from their mantles,” Bergin says. “This could readily lead to the natural production of hazes. Such hazes have been observed in the atmospheres of exoplanets and have the potential to change the calculus for what we consider habitable worlds.”

Haze around a planet might be a signpost that the planet has volatile carbon in its mantle. And more carbon, the backbone of life, in the mantle of a planet means that there is a chance it can be considered a habitable planet, for at least that it deserves a second glance, Bergin says.

“If this is true, then there could be a common class of haze planets with abundant volatile carbon, and what that means for habitability needs to be explored,” he says. “But then there’s the other aspect: What if you have an Earth-sized world, where you have more carbon than Earth has? What does that mean for habitability, for life? We don’t know, and that’s exciting.”

The study is published in Astrophysical Journal Letters.

Source: University of Michigan

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Nikki Haley on the path to 2024 presidential victory: 'This is a marathon'

Nikki Haley, the first and only woman in the 2024 presidential race, knows there’s still a long way to go until election day.

“This is a marathon, it’s not a sprint. I’m not concerned with where things are now. I’m concerned about touching as many voters as we can and watching that go,” the candidate told USA Today on Thursday. “It’s slow and steady wins the race.”

The former ambassador to the United Nations, 51, has kept her pace since launching her campaign earlier this year. 

The outlet said her campaign has hosted nearly 20 grassroots events in New Hampshire and more than 20 in Iowa.

NIKKI HALEY, 2024 REPUBLICAN CANDIDATE, VOWS TO SIGN FEDERAL ABORTION BAN IF ELECTED PRESIDENT

Nikki Haley

Republican presidential candidate and former U.N. Ambassador Nikki Haley speaks at a town hall event in New Hampshire on April 26, 2023, in Bedford, New Hampshire. Haley is the first, and thus far, the only female candidate to announce a 2024 run for president, a field that includes frontrunner and former President Donald Trump.  (Photo by Spencer Platt/Getty Images)

In the Granite State, Haley also said she was unconcerned regarding polling performance there, pointing to former Wisconsin Gov. Scott Walker’s lead in Iowa. He led the field there in summer 2015 but dropped out before the state’s caucuses after support for him fell. 

The former South Carolina governor is running on a multitude of issues, including some her fellow Republican contenders have been hammering as well. 

For example, she spotlights defending Second Amendment rights, cracking down on illegal immigration, creating jobs and a pro-life point of view on her website.

Notably, abortion has been a touchy subject for former President Donald Trump – something the newest GOP candidate Florida Gov. Ron DeSantis has focused on in recent weeks.

Haley, a mother to two children, has committed to signing a federal abortion ban, although noting she believes the prospect of such a ban getting through Congress is unlikely. Conversely, Trump said earlier this month that Florida’s six-week restriction was “too harsh.” 

Former UN Ambassador Nikki Haley holds a town hall

Republican presidential candidate and former UN Ambassador Nikki Haley holds a town hall meeting on March 9, 2023, in Nevada, Iowa.  (Photo by Scott Olson/Getty Images)

Trump has been on the trail for a while, but DeSantis is just officially crossing the start line. While DeSantis seeks to separate himself from Trump – widening the divide in a Friday interview with Ben Shapiro – Haley has called DeSantis “an echo” of the former president.

ONLY ON FOX: AS DESANTIS ENTERS THE RACE, HALEY ARUGES FLORIDA GOVERNOR IS ‘COPYING TRUMP’

While she is “unapologetically pro-life,” Haley reportedly told people attending the Saint Anselm College and New England Council’s “Politics and Eggs” event that she is going to “treat [the issue] with the respect it deserves.”

An April Fox News Poll showed a majority of American voters think the FDA-approved prescription medication used to end a pregnancy, mifepristone, should be legal.

To note further, around 70% of women in the U.S. were registered to vote in 2022, according to Statista. 

Nikki Haley in front of American flag

Nikki Haley speaks to hometown supporters during a campaign rally at The Grove in Lexington County, South Carolina on Thursday, April 6, 2023.  (Tracy Glantz/The State/Tribune News Service via Getty Images)

The article also highlighted that suburban women can make or break elections and that Haley believes she is in the right spot to capture those votes.

“I know the challenges they face. I know whether they’re taking care of elderly parents because I’m doing that. I know about their spouses in the military. I’m a military wife. I know about that,” she told USA Today. “I know about raising children and the concerns you have.”

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Haley pointed out that women focus on issues from education to border safety and national security.

“I know not only what they care about, but I also know how to communicate that to them because I can relate to what they’re feeling,” she said.

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Celine Dion cancels upcoming shows and 'will likely never tour again,' source says



CNN
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Celine Dion announced the cancellation of her “Courage World Tour” dates through 2024 and “will likely never tour again,” a source close to Dion told CNN Friday.”

“She is in a lot of pain,” the individual said. “She does daily physical therapy.”

“I’m so sorry to disappoint all of you once again,” an announcement on the singer’s social media read. “I’m working really hard to build back my strength, but touring can be very difficult even when you’re 100%. It’s not fair to you to keep postponing the shows, and even though it breaks my heart, it’s best that we cancel everything now until I’m really ready to be back on stage again. I want you all to know, I’m not giving up… and I can’t wait to see you again!”

Dion postponed several shows in December after she announced she had been diagnosed with stiff-person syndrome, a condition, she said, that doesn’t allow her “to sing the way I’m used to.”

The disorder is “a rare, progressive syndrome that affects the nervous system, specifically the brain and spinal cord,” according to the National Institute of Neurological Disorders and Stroke.

“While we’re still learning about this rare condition, we now know this is what’s been causing all of the spasms that I’ve been having,” Dion said at the time. “Unfortunately, these spasms affect every aspect of my daily life, sometimes causing difficulties when I walk and not allowing me to use my vocal cords to sing the way I’m used to.”

Tickets for her concerts will be refunded from their point of purchase.

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