- Israeli hostage Mia Schem reveals only reason Hamas captor didn’t rape her during 54 hellish days New York Post
- Freed hostage Mia Schem: ‘I experienced hell. There are no innocent civilians in Gaza’ The Times of Israel
- Mia Schem, an Israeli Hostage, Shares Harrowing Details of Gaza Captivity The New York Times
- ‘I was afraid of being raped – that was my biggest fear’: Mia Schem reveals daily torment of Hamas captor who Daily Mail
- ‘I Went Through a Holocaust’: Freed Israeli Hostage Shares Harrowing Details about Captivity in Gaza National Review
Tag Archives: hellish
Israeli hostage Mia Schem reveals only reason Hamas captor didn’t rape her during 54 hellish days – New York Post
- Israeli hostage Mia Schem reveals only reason Hamas captor didn’t rape her during 54 hellish days New York Post
- Freed hostage Mia Schem: ‘I experienced hell. There are no innocent civilians in Gaza’ The Times of Israel
- Mia Schem, an Israeli Hostage, Shares Harrowing Details of Gaza Captivity The New York Times
- ‘I Went Through a Holocaust’: Freed Israeli Hostage Shares Harrowing Details about Captivity in Gaza National Review
- Freed Israeli hostage Mia Schem reveals only reason she wasn’t raped by her captor: ‘I was closed in a dark room and…’ Hindustan Times
Massive Volcanic Outburst Detected on Jupiter’s Hellish Moon Io : ScienceAlert
The most powerful volcanic eruptions in the Solar System occur not on Earth, but on Io, a sulfurous moon orbiting the planet Jupiter.
And now, researchers from the Planetary Science Institute (PSI) in the US have noticed a recent outburst that’s been surprisingly productive, even for a hellish world like Io.
In the space around Jupiter, a torus of plasma created and fed by Io’s volcanic emissions grew significantly richer between July and September of last year and persisted until December, showing the moon underwent a spate of volcanic activity that released a huge amount of material.
For something that’s just a little bit bigger than Earth’s Moon, Io is an absolute beast of volcanism. It’s bristling with volcanoes, with around 150 of the 400 known volcanoes erupting at any given time, creating vast lakes of molten lava.
This is all down to its relationship with Jupiter: Io orbits on an elliptical path, resulting in variations in the gravitational pull that change the shape of the moon as it swings around the planet.
The other Galilean moons tug on Io too. This creates frictional heating inside Io, which then spews out molten material from its interior.
What happens to the volcanic emissions from Io then has an effect on Jupiter. Because Io has no magnetic field of its own, the sulfur dioxide escapes, forming a torus of plasma that orbits Jupiter.
This is what feeds the permanent ultraviolet auroras that shimmer at Jupiter’s poles – the most powerful auroras in the Solar System.
This complex interplay is fascinating in its own right, of course. But it can also help inform other interactions of a similar nature that may be occurring out there in the broader galaxy.
So PSI astronomer Jeff Morgenthaler has been keeping an eye on Io by using the PSI’s Io Input/Output observatory (IoIO) since 2017.
Jupiter is very big and very bright, so IoIO uses a coronagraphic technique: effectively minimizing the light shining off Jupiter so that Mogenthaler can see the light emitted by other things in the space around it, including the plasma torus.
This is how he sees that Io has a volcanic outburst every year; and how he was able to see that sulfur and sodium were being pumped into the torus in fall of last year.
However, while the quantities were huge, the torus was dimmer than other years. We don’t know what this means, yet, but unraveling it could tell us something new about the fiery dance between Jupiter and Io.
“This could be telling us something about the composition of the volcanic activity that produced the outburst or it could be telling us that the torus is more efficient at ridding itself of material when more material is thrown into it,” Morgenthaler says.
We’ll have to wait to learn more, but with IoIO on the ground and Juno currently orbiting Jupiter, additional information about the plasma torus will be coming in, especially since Juno can measure changes in Jupiter’s plasma environment.
In addition, Juno will be performing a flyby of Io in December 2023, so we’re looking forward to a wealth of information on the smelly yellow moon.
“Juno measurements,” Morgenthaler says, “may be able to tell us if this volcanic outburst had a different composition than previous ones.”
This Hellish Planet Orbits its Star Every 18 Hours. How Did it Get There?
Astronomers discovered 55 Cancri e in 2004. That was five years before NASA’s Kepler planet-hunting spacecraft was launched, and exoplanet science has come a long way in the intervening years. Astronomers discovered the planet with the radial velocity method rather than Kepler’s transit method. 55 Cancri e was the first super-Earth found around a main-sequence star. The 55 Cancri system was also the first star discovered with four, and then five, planets.
The discovery was big news then; over the years, follow-up work has revealed more details, including that 55 Cancri e is extremely close to its star and has a molten surface.
But one question remained unanswered: How did it get there?
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A new study published in Nature Astronomy shows how 55 Cancri e must have formed further away from the star in its solar system’s cooler reaches. The study is “Measured spin-orbit alignment of ultra-short-period super-Earth 55 Cancri e.” The lead author is Lily Zhao, a research fellow at the Flatiron Institute’s Center for Computational Astrophysics (CCA) in New York City.
55 Cancri is a binary star system about 41 light-years away. One star (55 Cancri A) is a K-type main sequence star, and the other (55 Cancri B) is a red dwarf. 55 Cancri e isn’t the only planet in the system. It has four siblings.
The new paper is based on observations made with the EXtreme PREcision Spectrograph (EXPRES) instrument on the 4.3-m Lowell Observatory Discovery Telescope at the Lowell Observatory in Arizona. It’s built for precise radial velocity measurements of planets as they orbit their stars.
As the study title suggests, the spin-orbit of planets is vital in understanding planets and their place in the evolution of the solar system they belong to. It’s particularly important when it comes to planets like 55 Cancri e because astronomers don’t understand how planets like it end up so close to their stars. More on that later.
55 Cancri e is known for being extremely close to its main sequence star, Cancri 55 A, most often referred to as simply Cancri 55. Cancri 55 is smaller and less massive than the Sun, so it’s also a little cooler. But that doesn’t matter to the planet.
55 Cancri e is classified as a super-Earth, but it’s far from Earth-like. (Many exoplanets are interesting because of potential habitability but don’t even mention habitability in this case.) It orbits so closely to the star that its surface is molten and reaches a temperature of 2000 Celsius. (3600 F.) It travels so rapidly that its year is only 17.5 hours long.
Because it’s so close to its star and orbits so quickly, 55 Cancri e is called an ultra-short period (USP) planet. Planets that complete an orbit in less than 24 hours are USPs.
The planet wasn’t always a blistering, molten inferno. That’s because it didn’t form in its current location.
“Astronomers expect that this planet formed much farther away and then spiralled into its current orbit,” said Debra Fischer. She’s from the National Science Foundation’s Division of Astronomical Sciences and is a senior author of the paper. “That journey could have kicked the planet out of the equatorial plane of the star, but this result shows the planet held on tight.”
But even though the planet formed further from the Sun than where it resides now, and it’s a super-Earth, it likely was never habitable. 55 Cancri e “… was likely so hot that nothing we’re aware of would be able to survive on the surface,” said lead author Zhao.
55 Cancri e isn’t the only planet to change orbit over time. The same thing happened in our Solar System. The Grand Tack Hypothesis says that Jupiter formed at 3.5 AU, migrated inward to 1.5 AU, then back out to 5.2 AU, where it orbits today. The Grand Tack Hypothesis explains a few things about our Solar System, including why Mars is so small.
Jupiter’s migrations helped shape the Solar System and may have influenced Mars’ fate. If Mars was once habitable, and it’s looking more and more like it was, Jupiter’s migration had to have affected it somehow. So understanding how exoplanets like 55 Cancri e migrate over time should help us understand exoplanet habitability in other solar systems. Such information is critical to finding just how common Earth-like environments might be in the universe and, by extension, how abundant extraterrestrial life may be.
The oddball planet is fascinating because it’s so unlike our planet or any other planet in our Solar System. For curious scientists, it’s more than just an oddball. They want to know how it ended up so close to its star.
That brings us back to the unusual planet’s spin-axis alignment.
It may seem counterintuitive that astronomers use a spectrograph, which measures light, to determine a planet’s motion. But it works because of the Doppler effect. The Doppler effect explains how light moving away from us is red-shifted and light moving toward us is blue-shifted. Cancri 55 e’s host star is spinning, meaning the light from the receding side is red-shifted. Conversely, the light from the approaching side is blue-shifted.
As Cancri 55 e transits in front of the star, the EXPRES instrument at the Lowell Observatory measures the star’s light precisely. Those measurements reveal apparent, but not real, deviations in the planet’s radial velocity, and those deviations tell astronomers about the planet’s orbit and spin relative to the star’s. The authors explain it best when they write, “Capturing the resultant net red/blueshift reveals the orientation of the planet’s orbital normal vector with respect to its host star’s spin vector, that is, the sky-projected stellar spin-orbit alignment or the stellar obliquity.”
The specific effect that the team measured when the planet transits the star is the Rossiter–McLaughlin (RM) effect. Explaining that in detail would mean going down a rabbit hole, and it’s beyond the scope of this article. But the image below does shed some light on it. It’s sufficient to say that the nature of the light changes, and EXPRES can measure it precisely, more precisely than older instruments.
Even though the planet’s actual radial velocity doesn’t change, the measured apparent change still shows the slight gravitational change that the planet induces on the star. Without that information, it isn’t easy to piece together Cancri 55 e’s story and how it got so close to its star. Because, as we know, it cannot have formed there.
The key finding is that Cancri 55 e orbits along its star’s equator while its four siblings don’t. Remember that the Cancri 55 system is a binary system, and the small red dwarf in the binary pair is quite distant from the larger star. But it still exerts its weaker gravity on the system, which explains why all five stars likely had an orbit not precisely aligned with the larger star’s rotation. Since it’s highly likely that the planet initially had the same orbital plane as its siblings, it shows that as it migrated inward, the primary star’s gravitational force pulled the planet into alignment with the star’s equator.
As far as what led Cancri 55 e to start its migration toward the star, there could be several causes. Planets are in constant motion, and when there are five of them, they exert influence on each other which can cause planets to migrate. It’s also possible that the planet formed out of the circumstellar disk with an initial misalignment.
“We’ve learned about how this multi-planet system — one of the systems with the most planets that we’ve found — got into its current state.”
Lily Ahao, lead author, Flatiron Institute’s Center for Computational Astrophysics.
“We’ve learned about how this multiplanet system — one of the systems with the most planets that we’ve found — got into its current state,” said study lead author Lily Zhao.
While this study can’t conclude exactly what caused Cancri 55 e to get so close to its star, it’s still important. Previous measurements of its spin-orbit alignment gave contradictory results because the instruments used to measure the alignment weren’t as precise.
Several theories attempt to explain how Ultra-Short Period planets end up in hellish locations. One theory says that due to the distant red dwarf, all of the planets should be misaligned with the primary star’s rotation. Another says that secular resonance between 55 Cancri e and the other planets excited the planet’s orbital eccentricity and inclination, misaligning it with the other planets and the star. But thanks to the precise measurements possible with EXPRES, the team has narrowed it down.
“The close alignment of the ultra-short-period, super-Earth 55 Cnc e’s orbit normal with its host star’s spin axis places constraints on theories for how USPs migrate to their present-day positions and how they interact with other planets in compact multiplanet systems,” the authors write in their conclusion. “This measurement additionally gives clues as to why none of the other known planets around 55 Cnc transit and the possible role of 55 Cnc’s distant stellar companion.”
As is usually the case, better data leads to better conclusions. In this case, the powerful EXPRES instrument helped the team understand this unusual planet better. “The EXPRES data used in this analysis have a consistent and often a higher signal-to-noise ratio (SNR), as well as lower uncertainties than the RV measurements previously used,” they write. Here they’re referring to instruments like HARPS, the High Accuracy Radial velocity Planet Searcher, another spectrometer designed to find exoplanets.
“Our precision with EXPRES today is more than 1,000 times better than what we had 25 years ago…”
Debra Fischer, senior author, National Science Foundation’s Division of Astronomical Sciences
The team concludes that the close alignment between the planet’s orbit and the host star’s axis favours one explanation over others. “The close alignment of 55 Cnc e’s orbit normal with its host star’s stellar axis preliminarily favours the low eccentricity and planetary obliquity tide models.” Low eccentricity means the planet’s orbit wasn’t completely circular but didn’t deviate much from a circle. Planetary obliquity is the angle between a planet’s orbit and its spin axis. And that’s as deep as we’re going.
Remember that this star system is 41 light-years away—an enormous distance! And even though Cancri 55 e is several times more massive than Earth, it’s still impossibly tiny from this far away. That’s why improved instruments like EXPRESS are so important in astronomy.
“Our precision with EXPRES today is more than 1,000 times better than what we had 25 years ago when I started working as a planet hunter,” Fischer said. “Improving measurement precision was the primary goal of my career because it allows us to detect smaller planets as we search for Earth analogs.”
EXPRES is newer than HARPS and reveals more detail in transiting exoplanets than HARPS can. And the detail is helping us understand solar system dynamics in remote systems like Cancri 55 and may eventually help explain our own Solar System’s history. “With this robust measurement using EXPRES data, we can place constraints on the different proposed dynamical histories for the 55 Cnc system.”
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Jupiter’s Moon Io Might Have a Hellish Magma Ocean Beneath Its Surface
There are more than 200 moons in the solar system, but none quite like Io, the third largest of Jupiter’s 80 moons. Io is really, really volcanic. In fact, it’s peppered with so many hundreds of powerful active volcanoes that there must be something unusual beneath its crust.
That something could be a thick moonwide layer of molten rock—or a “subsurface magma ocean,” according to a new study published in the Planetary Science Journal on Nov. 16 from Yoshinori Miyazaki and David Stevenson, planetary scientists at the California Institute of Technology.
That possible super-hot sea of melted rock—which is unique in the solar system—could harbor secrets, weird mechanisms for forming moons and planets, and even recipes for exotic alien life. Only further scrutiny of the 2,200-mile-diameter moon will tell.
Miyazaki and Stevenson aren’t the first scientists to make an educated guess at what lies beneath Io’s potentially 20-mile-thick rocky crust. It’s been the subject of heated debate for years. But their new peer-reviewed study of the moon’s mantle might be the most thorough yet.
A volcanic explosion on Io, Jupiter’s third largest moon, as captured by NASA’s New Horizon spacecraft.
NASA/JPL/University of Arizona
To peer beneath Io’s surface, Miyazaki and Stevenson revisited reams of data from NASA’s Galileo probe, which orbited Jupiter for eight years starting in 1995. Initial analysis of the probe’s magnetic data led to a loose consensus that Io’s mantle—the layer under the moon’s crust—includes a 30-mile thick top layer that should be “molten or partially molten,” according to NASA.
Compare this to Earth’s own mantle, as well as the mantles of every other planetary body in the solar system, which are mostly solid and consist largely of ice or superheated rocks. Broadly speaking, planetary scientists reading the Galileo data assumed Io either has an underground magma ocean or a kind of sponge-like rocky outer mantle soaked in magma.
A fresh look at the data led Miyazaki and Stevenson concludes it’s the molten sea. They based their conclusion on estimates of the mantle’s temperature via analysis of Io’s volcanoes, which can spew magma hundreds of miles into the moon’s sulfur dioxide atmosphere. The top of the mantle might register as hot as 2,800 degrees Fahrenheit.
That’s hot. But not hot enough to sustain a spongy interior. The analysis is complicated, but it boils down to this: Like a pot of gravy on a stovetop, Io would need a lot of heat to stay consistently spongy in its upper mantle. Without enough heat, the gravy—er, the spongy rock—would separate: rock on bottom, magma on top.
Miyazaki and Stevenson crunched the numbers, calculating the heat from Io’s core as well as the effects of its weird, highly-elliptical orbit, which sloshes the mantle, spreads heat around, and keeps Io from ever permanently cooling.
They concluded that the gravy would separate. “The amount of internal heating is insufficient to maintain a high degree of melting,” they wrote. Hence what they believe could be a topmost magma ocean.
Luckily, we’ll know more soon. NASA’s Juno probe, which arrived around Jupiter in 2016, is scheduled to take readings of Io in 2023 and 2024—specifically measuring the “Love number,” a gauge of a planet’s rigidity or lack thereof. “If a large Love number is found, we can say with more certainty that a magma ocean exists beneath Io’s surface,” Miyazaki told The Daily Beast.
We already knew Io is weird. It’s possible it’s even weirder—and that weirdness could have implications across the space sciences. “I don’t think it greatly changes understanding of planetary formation, but it does change how we view the internal structure and thermal evolution of tidally heated bodies like Io,” David Grinspoon, a senior scientist with the Arizona-based Planetary Science Institute, told The Daily Beast.
Io and Europa, Jupiter’s two largest moons, captured by NASA’s Juno spacecraft.
NASA/JPL-Caltech/SwRI/MSSS/Roman Tkachenko
Lurking in the academic shadows are the astrobiologists. The experts in how and where life could evolve in the universe. If there’s extraterrestrial life out there somewhere and it looks like Earth life, we should expect to find it—or evidence of its extinction—on planets and moons that have, or had, Earthlike environments. Mars. Venus. A moon of Saturn called Enceladus.
But volcanoes with their extreme transfers of energy are widely considered key components of a living ecosystem. So planets and moons with lots of volcanoes are great places to look for E.T. In theory, that should include Io.
However, Io might have too many volcanoes. So if there’s life evolving there, it’s probably very strange life that really likes heat. “Lava tubes could be creating a condition favorable for microbes,” Miyazaki said.
The question, for astrobiologists, is whether a magma ocean would create more or fewer lava tubes than a magma sponge. “I don’t have an explicit answer,” Miyazaki said. “But it’s interesting to think about such implications.”
Dirk Schulze-Makuch, an astrobiologist at the Technical University Berlin, has long advocated a thorough search for life on Io. A magma ocean would only spoil that search if it were really close to the surface. A nice thick crust should insulate the outermost regions of the planet from scouring heat, and preserve the potential for evolution. “There seems to be quite a bit of crust,” Schulze-Makuch told The Daily Beast.
If anything, the possibility of a magma ocean on Io just underscores how interesting and exciting the moon is—and why it should be a top target for future space probes, Schulze-Makuch said. “Io is a unique kind of moon, very dynamic, and we should not dismiss it altogether.”
“Terrifying Rotting Flesh Wound:” The U.S. Spider with One Hellish Bite
Spiders are one of the hallmarks of Halloween. But did you know there is a spider living in North America with venom capable of destroying human flesh?
The brown recluse spider (Loxosceles reclusa) is native to the U.S. and has established itself in a number of states, including Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, Ohio, Oklahoma, Tennessee, and Texas.
The spider, which is considered among the most dangerous in North America, has also been spotted outside this range in other states. But these tend to be isolated cases where brown recluses have been inadvertently transported to these areas by humans.
This species is common within its range and can is often found in homes, but as the name suggests they tend to stay hidden and are not aggressive, Jerome Goddard, a professor of medical entomology at Mississippi State University’s Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, told Newsweek.
iStock
As a result, brown recluse bites are relatively rare and when they do occur, it is usually because a spider is trapped against the skin and feels threatened, for example if someone rolls onto one while sleeping.
The venom of this spider can cause damage to local tissues and may produce a variety of symptoms. In many cases, the individual who is bitten experiences no notable effects.
“Brown recluse bite reactions may vary from no reaction at all, to a mild red wound, to a terrifying rotting flesh wound,” Goddard said.
The bite of brown recluse may feel like a pinprick and is usually painless until three to eight hours later, when it might become red, swollen and tender, according to Goddard.
The central area of a brown recluse bite eventually becomes pale or blue, not red, Goddard said. After 24 hours have passed, intense pain may develop. Later, a black scab may appear and, eventually, an area around the site may decay and slough away in a process known as “necrosis”—or death of body tissue—producing an ulcer.
Finally, the edges of the wound thicken and become raised, whereas the central area is filled by scar tissue. Healing may take months, and the victim could be left with a sunken scar.
“Their bites can produce nasty, slow-to-heal lesions that leave unsightly scars,” Goddard said.
The primary component of brown recluse venom that causes necrosis in the skin is likely an enzyme called sphingomyelinase D, which degrades fibrinogen (a clotting factor) and fibronectin (a protein that plays a role in tissue repair).
“Sphingomyelinase D also disrupts basement membrane structures, which act as a platform for cells to grow,” Goddard said. “All of this leads to local tissue death.”
The proportion of brown recluse bites that result in necrotic wounds is not entirely clear because many self-reported bites are actually something else, such as a staph infection, according to Goddard.
Getty Images
But the entomologist said his best estimate was that around 10 to 50 percent of brown recluse bites lead to necrosis in some form.
The lack of development of necrosis may be due to factors unique to the immune system of the individual that is bitten.
“Or like venomous snakes, perhaps brown recluse spiders may deliver ‘dry’ bites wherein they withhold or don’t inject much venom,” Goddard said.
In rare cases—perhaps less than one percent of incidents—brown recluse bites can lead to a potentially serious systemic illness roughly two to three days after the bite that affects the whole body.
This illness—known as “systemic loxoscelism”—is characterized by anemia, blood in the urine, fever, rash, nausea, vomiting and coma. In very rare cases, deaths have resulted from the systemic reaction of a brown recluse bite. The local necrotic wounds are not fatal.
The treatment of brown recluse bites is controversial and appears to be constantly changing, the Goddard said.
“A specific antidote—or antivenin—has shown success in patients prior to development of the necrotic lesion, but I don’t think it is widely available,” he said. “Also, some brown recluse bites are unremarkable, not leading to necrosis; therefore, treatment may not be needed in those cases.”
Some research has indicated that the application of ice to the bite site is effective. This may be because the necrotic enzyme sphingomyelinase D increases in activity as temperature rises.
At one time, early, total surgical excision of the bite site followed by skin-grafting was recommended. But more recent evidence no longer supports wound excision as a treatment, according to Goddard.
Some scientists and physicians have reported success in treating the individual with a medication known as dapsone. But some evidence shows that this drug is completely ineffective.
ESA outlines how Venus mission will get to hellish planet
Europe’s planned Venus exploration mission will depend on a challenging aerobraking procedure to lower its orbit, which will test the thermal resiliency of the spacecraft’s materials to their limits.
The EnVision mission, expected to launch in the early 2030s, will study the geology and atmosphere of Venus, the hellish planet that once may have looked quite like Earth but turned into a scorched hostile world due to a runaway greenhouse effect.
To get EnVision to its target orbit, 310 miles (500 kilometers) above Venus’ surface (which is so hot that it would melt lead), will take thousands of passes through the planet’s thick atmosphere over a period of two years, the European Space Agency (ESA) said in a statement (opens in new tab).
“EnVision as currently conceived cannot take place without this lengthy phase of aerobraking,” ESA’s EnVision study manager, Thomas Voirin, said in the statement.
Related: How Venus turned into hell, and how Earth is next
The van-sized spacecraft, which will launch on Europe’s future Ariane 6 rocket, will not be able to carry enough fuel to slow itself down in Venus’ orbit using onboard propulsion. Instead, it will use the aerobraking procedure and follow a highly elliptical orbit that will take it periodically to within 80 miles (130 km) of Venus’ surface at its closest and about 155,000 miles (250,000 km) from the planet at its farthest point.
ESA previously used aerobraking to slow down the ExoMars Trace Gas Orbiter before it entered its scientific orbit around Mars. But Mars’ atmosphere is much thinner than that of Venus, and its gravity is much lower, which affects the speed of the orbiting spacecraft.
“Aerobraking around Venus is going to be much more challenging than for Trace Gas Orbiter,” Voirin said. “The gravity of Venus is about 10 times higher than that of Mars. This means velocities about twice as high as for TGO will be experienced by the spacecraft when passing through the atmosphere, and heat is generated as a cube of velocity.”
ESA briefly tested aerobraking around Venus during the final months of the Venus Express mission, which eventually spiraled toward the planet and burned up in the atmosphere in 2014. As Venus Express was already at the end of its mission, spacecraft controllers didn’t worry about the damage sustained by the spacecraft caused by the heat. EnVision, on the other hand, will be expected to explore Venus for at least four years.
Engineers are already busy working out the right materials that would enable EnVision to withstand the extreme conditions. In addition to the heat experienced during the aerobraking procedure, the spacecraft will also be exposed to very high concentrations of highly reactive atomic oxygen. Atomic oxygen is a form of oxygen present in the upper layers of Earth’s atmosphere, which consists of a single oxygen atom. Atomic oxygen, a nemesis of all low Earth orbit spacecraft, burned thermal blankets on several NASA space shuttle missions in the 1980s.
Observations by previous Venus missions showed that atomic oxygen is present in the upper layers of Venus’ atmosphere at concentrations similar to those around Earth.
“The concentration is quite high. With one pass it doesn’t matter so much, but over thousands of times it starts to accumulate and ends up with a level of atomic oxygen fluence we have to take account of, equivalent to what we experience in low Earth orbit, but at higher temperatures,” Voirin said.
ESA is currently testing materials for their ability to withstand both the heat and the concentration of atomic oxygen expected during EnVision’s aerobraking and hopes to have some candidate materials selected by the end of this year.
“We want to check that these parts are resistant to being eroded, and also maintain their optical properties — meaning they do not degrade or darken, which might have knock-on effects in terms of their thermal behavior, because we have delicate scientific instruments that must maintain a set temperature,” Voirin said. “We also need to avoid flaking or outgassing, which leads to contamination.”
Venus, sometimes considered Earth’s twin because of their similar sizes, has lately been somewhat sidelined by solar system explorers as the potentially more habitable Mars (which is likelier to harbor traces of life) has become the favorite. But a 2020 study that detected molecules that could be traces of living organisms in the planet’s sulfur-rich clouds sparked a new surge of interest in Venus.
In addition to Europe, NASA has plans to send orbiters to the scorching-hot planet: The DAVINCI+ and VERITAS missions, which are expected to launch between 2028 and 2030. Currently, a lone spacecraft, Japan’s Akatsuki, is orbiting Venus, studying its dense atmosphere in an attempt to unravel the mysteries of its harsh climate.
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NASA’s DAVINCI Space Probe To Plunge Through Hellish Atmosphere of Venus
NASA’s DAVINCI mission will study the origin, evolution, and present state of Venus in unprecedented detail from near the top of the clouds to the planet’s surface. The mission’s goal is to help answer longstanding questions about our neighboring planet, especially whether Venus was ever wet and habitable like Earth. Credit: NASA’s Goddard Space Flight Center
Last year, NASA selected the DAVINCI mission as part of its Discovery program. It will investigate the origin, evolution, and present state of
Now, in a recently published paper, NASA scientists and engineers give new details about the agency’s Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission, which will descend through the layered Venus atmosphere to the surface of the planet in mid-2031. DAVINCI is the first mission to study Venus using both spacecraft flybys and a descent probe.
DAVINCI, a flying analytical chemistry laboratory, will measure critical aspects of Venus’ massive atmosphere-climate system for the first time, many of which have been measurement goals for Venus since the early 1980s. It will also provide the first descent imaging of the mountainous highlands of Venus while mapping their rock composition and surface relief at scales not possible from orbit. The mission supports measurements of undiscovered gases present in small amounts and the deepest atmosphere, including the key ratio of hydrogen isotopes – components of water that help reveal the history of water, either as liquid water oceans or steam within the early atmosphere.
NASA has selected the DAVINCI+ (Deep Atmosphere Venus Investigation of Noble-gases, Chemistry and Imaging +) mission as part of its Discovery program, and it will be the first probe to enter the Venus atmosphere since NASA’s Pioneer Venus in 1978 and USSR’s Vega in 1985. Named for visionary Renaissance artist and scientist, Leonardo da Vinci, the DAVINCI+ mission will bring 21st-century technologies to the world next door. DAVINCI+ may reveal whether Earth’s sister planet looked more like Earth’s twin planet in a distant, possibly hospitable past with oceans and continents. Credit: NASA’s Goddard Space Flight Center
The mission’s carrier, relay, and imaging spacecraft (CRIS) has two onboard instruments that will study the planet’s clouds and map its highland areas during flybys of Venus and will also drop a small descent probe with five instruments that will provide a medley of new measurements at very high precision during its descent to the hellish Venus surface.
“This ensemble of chemistry, environmental, and descent imaging data will paint a picture of the layered Venus atmosphere and how it interacts with the surface in the mountains of Alpha Regio, which is twice the size of Texas,” said Jim Garvin, lead author of the paper in the Planetary Science Journal and DAVINCI principal investigator from NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “These measurements will allow us to evaluate historical aspects of the atmosphere as well as detect special rock types at the surface such as granites while also looking for tell-tale landscape features that could tell us about erosion or other formational processes.”
DAVINCI will send a meter-diameter probe to brave the high temperatures and pressures near Venus’ surface to explore the atmosphere from above the clouds to near the surface of a terrain that may have been a past continent. During its final kilometers of free-fall descent (artist’s impression shown here), the probe will capture spectacular images and chemistry measurements of the deepest atmosphere on Venus for the first time. Credit: NASA/GSFC/CI Labs
DAVINCI will make use of three Venus gravity assists, which save fuel by using the planet’s gravity to change the speed and/or direction of the CRIS flight system. The first two gravity assists will set CRIS up for a Venus flyby to perform remote sensing in the ultraviolet and the near infrared light, acquiring over 60 gigabits of new data about the atmosphere and surface. The third Venus gravity assist will set up the spacecraft to release the probe for entry, descent, science, and touchdown, plus follow-on transmission to Earth.
The first flyby of Venus will be six and half months after launch and it will take two years to get the probe into position for entry into the atmosphere over Alpha Regio under ideal lighting at “high noon,” with the goal of measuring the landscapes of Venus at scales ranging from 328 feet (100 meters) down to finer than one meter. Such scales enable lander-style geologic studies in the mountains of Venus without requiring landing.
The DAVINCI deep atmosphere probe descends through the dense carbon dioxide atmosphere of Venus towards the Alpha Regio mountains. Credit: NASA’s Goddard Space Flight Center
Once the CRIS system is about two days away from Venus, the probe flight system will be released along with the titanium three foot (one meter) diameter probe safely encased inside. The probe will begin to interact with the Venus upper atmosphere at about 75 miles (120 kilometers) above the surface. The science probe will commence science observations after jettisoning its heat shield around 42 miles (67 kilometers) above the surface. With the heatshield jettisoned, the probe’s inlets will ingest atmospheric gas samples for detailed chemistry measurements of the sort that have been made on
DAVINCI is tentatively scheduled to launch June 2029 and enter the Venusian atmosphere in June 2031.
“No previous mission within the Venus atmosphere has measured the chemistry or environments at the detail that DAVINCI’s probe can do,” said Garvin. “Furthermore, no previous Venus mission has descended over the tesserae highlands of Venus, and none have conducted descent imaging of the Venus surface. DAVINCI will build on what Huygens probe did at Titan and improve on what previous in situ Venus missions have done, but with 21st century capabilities and sensors.”
Reference: “Revealing the Mysteries of Venus: The DAVINCI Mission” by James B. Garvin, Stephanie A. Getty, Giada N. Arney, Natasha M. Johnson, Erika Kohler, Kenneth O. Schwer, Michael Sekerak, Arlin Bartels, Richard S. Saylor, Vincent E. Elliott, 24 May 2022, The Planetary Science Journal.
DOI: 10.3847/PSJ/ac63c2
NASA Goddard is the principal investigator institution for DAVINCI and will perform project management for the mission, provide science instruments as well as project systems engineering to develop the probe flight system. Goddard also leads the project science support team with an external science team from across the US. Discovery Program class missions like DAVINCI complement NASA’s larger “flagship” planetary science explorations, with the goal of achieving outstanding results by launching more smaller missions using fewer resources and shorter development times. They are managed for NASA’s Planetary Science Division by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama.
Major partners for DAVINCI are Lockheed Martin, Denver, Colorado, The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, NASA’s Jet Propulsion Laboratory, Pasadena, California, Malin Space Science Systems, San Diego, California, NASA’s Langley Research Center, Hampton, Virginia, NASA’s Ames Research Center at Moffett Federal Airfield in California’s Silicon Valley, and KinetX, Inc., Tempe, Arizona, as well as the University of Michigan in Ann Arbor.
‘Ghost’ fossils preserve haunting record of ancient life on a hellish Earth
Ghostly imprints of tiny plankton-like creatures have been found haunting the sediments of prehistoric oceans at a time when such organisms were thought to be extinct. The so-called nannofossil imprints reveal that the organisms survived acidic oceans caused by climate change, and could offer a clue for how modern creatures can endure rising ocean temperatures, researchers said.
Nannofossils are the remains of marine plankton called coccolithophores (cox-oh-LITH’-oh-fours), which belong to the class Prymnesiophyceae and still exist today at the bottom of many ocean food chains. Each of these single-celled, algae-like organisms measures less than 0.001 inch (30 micrometers) wide, and is surrounded by a hard layer of geometric calcium scales, according to the Faculty of Geosciences at the University of Bremen in Germany. And these nannofossils are incredibly abundant.
“There are way, way more nannofossils than any other kind of fossils,” Paul Bown, a micropaleontologist at University College London, U.K., and co-author of the new study, told Live Science. “It means we can really be statistically robust, because we see so many of them.”
When these tiny plankton die, they sink to the seafloor, where their calcium shells slowly accumulate. Over time, these piles of white mineralized scales, known as coccoliths, are pressed together to form walls of chalk. A classic example, according to Brown, is the famous White Cliffs of Dover in England. “The white chalk cliffs are white because they’re almost 100% nannofossils,” Bown said.
Related: We finally know how trilobites mated, thanks to new fossils
However, there are points in the fossil record where coccolithophores appear to suddenly vanish, only to return mysteriously millions of years later. “You get these abrupt changes in the sediment where you go from almost pure white sediments into black sediments,” Bown said. These points coincide with ancient ocean warming events, during which seawater became more acidic as it reacted with increased carbon dioxide from the atmosphere. As ocean pH dropped during these events, it ate away at the coccolithophores’ calcium shells, much like vinegar can dissolve an eggshell, according to research from the National Oceanic and Atmospheric Administration (NOAA).
Scientists once thought that most species of calcium-coated plankton in these acidic seas were wiped out en masse multiple times and replaced by non-shelled species, whose bodies decomposed into dark, sludgy goop and later hardened into rock.
Bown’s co-author Sam Slater, a micropaleontologist at the Swedish Museum of Natural History in Stockholm, previously concluded much the same. But then Slater noticed something strange during research for another study seeking traces of ancient pollen, while examining black sediments from a warming event during the Jurassic period (201 million to 145 million years ago). Under a powerful microscope, Slater detected tiny geometric imprints in the rock, and he realized that these imprints were shaped exactly like coccolithophores.
Slater reached out to Bown and a handful of other specialists to help investigate. Sure enough, the rock was stamped with coccolithophores. “These were spectacularly preserved impressions,” Bown said.”I could identify these things down to the species level.”
Intrigued by this discovery, the researchers then examined fossil sediments from other Jurassic sites around the world, as well as samples from two warming events during the Cretaceous period (145 million to 66 million years ago). “And we found these impressions, these ghost fossils, wherever we looked,” Bown said.
These results suggest that, contrary to previous research, some coccolithophores survived catastrophic ocean acidification and warming die-offs, even as other species went extinct. But the low ocean pH dissolved their shells posthumously, erasing them from the fossil record.
This information could help shed light on our current climate catastrophe, the researchers said, which is already eating away at calcium-rich coral reefs, according to Smithsonian. If the coccolithophores can adapt to warmer, more acidic conditions, it may be good news for modern creatures further up the food chain.
However, Bown warns against equating ancient warming events too closely with modern climate change, which is happening at roughly 10 times the rate of previous catastrophes, according to research published in 2019 in the journal Paleoceanography and Paleoclimatology.
“It’s a cautionary tale,” Bown said, “And you have to be careful how you go and read the rocks.”
The new study was published May 19 in the journal Science.
Originally published on Live Science.
‘Weird’, Long Lost Rocks Could Explain How a Hellish Earth Became Habitable
Early Earth is often described as ‘Hadean’ for good reason. Arising from the ashes of a collision that gave us our Moon, the primordial eon was characterized by hellish heat trapped beneath a thick blanket of carbon dioxide and water vapor.
Strangely those conditions should have been inhospitable for far longer than they were. By around 4 billion years ago – following just a few hundred million years or so of cooling – our planet was already starting to look remarkably habitable.
Any explanation of Earth’s dramatic transformation would have to take into account the rapid loss of its greenhouse gases, allowing the planet to cool and its water vapor to condense into oceans.
The only problem is that this period in our planet’s history left few traces of its geology behind. Scabs of crystallized mineral bobbing about on magma oceans would have long since sunk into the abyss, taking evidence of the planet’s surface conditions with them.
So any hypotheses we come up with to solve the mystery of the missing gas have to rely on mostly circumstantial forms of evidence.
Two researchers from Yale University recently ran the numbers on a rather speculative scenario involving ‘weird’ rocks that no longer exist on Earth’s surface, soaking up all that CO2. And the idea seems to check out.
“Somehow, a massive amount of atmospheric carbon had to be removed,” says planetary scientist Yoshinori Miyazaki, who is now working at the California Institute of Technology.
“Because there is no rock record preserved from the early Earth, we set out to build a theoretical model for the very early Earth from scratch.”
What we know about the Hadean eon on Earth largely comes from astrophysical and geochemical models of planetary formation.
Our Earth-Moon system was most likely the product of a collision between two proto-planets, one roughly Mars-sized and the other more or less the mass of Earth today.
What settled out of that mess of volatiles and rock would have been a molten lump of swirling minerals and gas that was kept warm by a constant downpour of rubble from space.
From these origins, we might imagine a long period of heat and chaos, perpetuated by a greenhouse atmosphere of carbon dioxide and water. One need only look to our neighbor, Venus, to get a sense of what that might look like.
Amid the scant bits of mineral evidence we do have from the Hadean are signs that it already harbored oceans after just a few hundred million years of cooling.
By the eon’s end around 4 billion years ago, the carbon cycle seems to have stabilized temperatures to the point life could exist rather happily.
One possibility is that the carbon in the atmosphere could have dissolved into the oceans, transforming into solid carbonates, which could have sunk and become embedded in the mantle’s currents.
It’s a nice idea, but to even give it half a thought it pays to know if the numbers add up.
So Miyazaki and his colleague Jun Korenaga pulled together models on fluid mechanics, heat movement, and atmospheric physics to see if they could make the hypothesis work.
The results suggest it could … if a certain kind of rock was exposed on our planet’s surface.
“These rocks would have been enriched in a mineral called pyroxene, and they likely had a dark greenish color,” says Miyazaki.
“More importantly, they were extremely enriched in magnesium, with a concentration level seldom observed in present-day rocks.”
A rapidly churning crust of wet, molten rock packed with pyroxene could account for a rapid loss of all that carbon dioxide in a stabilizing process that would take millions, rather than billions of years.
And then, following a cooling that gave us a regenerating crust consisting of a handful of slowly moving plates, all of that magnesium-rich rock would be left far beneath our feet.
As the crust rapidly turned over, water-logged minerals would have quickly dehydrated, filling the oceans to levels we see today.
The scenario is an intriguing one, not least because such a phenomenon would have helped kick-start life in other ways.
“As an added bonus, these ‘weird’ rocks on the early Earth would readily react with seawater to generate a large flux of hydrogen, which is widely believed to be essential for the creation of biomolecules,” says Korenaga.
It’s the kind of science that’s just begging for hard evidence, which lies buried both deep in time and far under the surface.
No doubt Earth’s ‘hellish’ period will keep its mysteries a little longer. But bit by bit we’re coming to an understanding of why our planet became the paradise we see today.
This research was published in Nature.