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First Habitable-Zone, Earth-Sized Exoplanet Discovered With Planet-Hunter TESS – SciTechDaily

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TOI 700, a planetary system 100 light-years away in the constellation Dorado, is home to TOI 700 d, the first Earth-size habitable-zone planet discovered by NASA’s Transiting Exoplanet Survey Satellite. Credit: NASA’s Goddard Space Flight Center

TESS, the Transiting Exoplanet Survey Satellite, was launched in 2018 with the goal of discovering small planets around the Sun’s nearest neighbors, stars bright enough to allow for follow-up characterizations of their planets’ masses and atmospheres. TESS has so far discovered seventeen small planets around eleven nearby stars that are M dwarfs — stars that are smaller than the Sun (less than about 60% of the Sun’s mass) and cooler (surface temperatures less than about 3900 kelvin). In a series of three papers that appeared together this month, astronomers report that one of these planets, TOI-700d, is Earth-sized and also located in its star’s habitable zone; they also discuss its possible climate.

CfA astronomers Joseph Rodriguez, Laura Kreidberg, Karen Collins, Samuel Quinn, Dave Latham, Ryan Cloutier, Jennifer Winters, Jason Eastman, and David Charbonneau were on the teams that studied TOI-700d, one of three small planets orbiting one M dwarf star (its mass is 0.415 solar masses) located one hundred and two light-years from Earth. The TESS data analysis found the tentative sizes of the planets as being approximately Earth-sized, 1.04, 2.65 and 1.14 Earth-radii, respectively, and their orbital periods as 9.98, 16.05, and 37.42 days, respectively.

This illustration of TOI 700 d is based on several simulated environments for an ocean-covered version of the planet. Credit: NASA’s Goddard Space Flight Center

In our solar system, Mercury orbits the Sun in about 88 days; it is so close to the Sun that its temperature can reach over 400 Celsius. But because this M-dwarf star is comparatively cool the orbit of its third planet, even though much closer to the star than Mercury is to the Sun, places it in the habitable zone – the region within which the temperatures allow surface water (if any) to remain liquid when there is also an atmosphere. That makes this Earth-sized planet TOI-700d particularly interesting as a potential host for life.

The TESS detections were exciting but uncertain: the signals were faint and a small possibility remained that the TOI-700d detection was spurious. Because of the potential importance of finding a nearby Earth-sized planet in a habitable zone, the TESS scientists turned to the IRAC camera on the Spitzer Space Observatory for confirmation. Before being turned off by NASA in February 2020, the IRAC camera was by far the most sensitive near infrared camera in space.

A schematic of the planets around the nearby M dwarf star TOI-700, discovered by TESS. The third (the farthest planet from the star), TOI-700d, lies within the star’s habitable zone (shown in green). Using the IRAC camera on Spitzer, the team refined the planet’s mass as 2.1 Earth-masses and 1.14 Earth-radii. (The scale shows 0.2 astronomical units; AU being the average Earth-Sun distance.) Credit: Rodriguez et al 2020

The TESS team observed TOI-700 with IRAC in October of 2019 and January of 2020, acquiring clear detections of the planets with about twice the signal-to-noise of TESS, enough to give a 61% improvement in the planet’s orbit and to significantly refine our knowledge of its other characteristics, refining the radius as above and finding the mass to be 2.1 Earth-masses. The results, especially when compared with other planets’ properties, suggest that this planet may be rocky and likely to be “tidally locked” with one side of the planet always facing the star.

If there were liquid water on the surface of TOI-700d, the astronomers argue, there would also be water-bearing clouds in the atmosphere, and the team uses climate system models to estimate its possible properties and what more sensitive measurements might find. They conclude, however, that pending space missions, including JWST, will probably lack the sensitivity to detect atmospheric features by a factor of ten or more. Their detailed climate studies will nevertheless help astronomers constrain the kinds of telescopes and instruments that will be needed to investigate this exciting new neighbor.

[embedded content]
NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star’s habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. Scientists confirmed the find, called TOI 700 d, using NASA’s Spitzer Space Telescope and have modeled the planet’s potential environments to help inform future observations. Credit: NASA’s Goddard Space Flight Center

References:

“The First Habitable-zone Earth-sized Planet from TESS. I. Validation of the TOI-700 System” by Emily A. Gilbert, Thomas Barclay, Joshua E. Schlieder, Elisa V. Quintana, Benjamin J. Hord, Veselin B. Kostov, Eric D. Lopez, Jason F. Rowe, Kelsey Hoffman, Lucianne M. Walkowicz, Michele L. Silverstein, Joseph E. Rodriguez, Andrew Vanderburg, Gabrielle Suissa, Vladimir S. Airapetian, Matthew S. Clement, Sean N. Raymond, Andrew W. Mann, Ethan Kruse … Benjamin J. Shappee, Mackennae Le Wood and Jennifer G. Winters, 14 August 2020, The Astronomical Journal.
DOI: 10.3847/1538-3881/aba4b2

“The First Habitable-zone Earth-sized Planet from TESS. II. Spitzer Confirms TOI-700 d” by Joseph E. Rodriguez, Andrew Vanderburg, Sebastian Zieba, Laura Kreidberg, Caroline V. Morley, Jason D. Eastman, Stephen R. Kane, Alton Spencer, Samuel N. Quinn, Ryan Cloutier, Chelsea X. Huang, Karen A. Collins, Andrew W. Mann, Emily Gilbert, Joshua E. Schlieder, Elisa V. Quintana, Thomas Barclay, Gabrielle Suissa, Ravi kumar Kopparapu … Philip S. Muirhead, Elisabeth Newton, Mark E. Rose, Joseph D. Twicken and Jesus Noel Villaseñor, 14 August 2020, The Astronomical Journal.
DOI: 10.3847/1538-3881/aba4b3

“The First Habitable-zone Earth-sized Planet from TESS. III. Climate States and Characterization Prospects for TOI-700 d” by Gabrielle Suissa, Eric T. Wolf, Ravi kumar Kopparapu, Geronimo L. Villanueva, Thomas Fauchez, Avi M. Mandell, Giada Arney, Emily A. Gilbert, Joshua E. Schlieder, Thomas Barclay, Elisa V. Quintana, Eric Lopez, Joseph E. Rodriguez and Andrew Vanderburg, 14 August 2020, The Astronomical Journal.
DOI: 10.3847/1538-3881/aba4b4

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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