News Feeds

When bacteria were put in alternating environments, some became better at evolving to cope with the changes – evidence that “evolvability” can be gained through natural selection

The protective bubble around the sun retreated dramatically after colliding with a freezing interstellar cloud, leaving much of the solar system exposed to radiation that may have shaped our evolution, a study suggests

Back in the 1960 there was a race to land people on the Moon between the US and the Soviet Union. This was very much a part of the cold war, with each country interested in showing off its technical prowess to the world with a technology closely related to that needed to deliver nuclear warheads. All the while everyone insisted this was all peaceful exploration for all mankind. But as a result we advanced our space technology with a lot of downstream effects. And of course there are many legitimate commercial uses of space, which has kept the space industries going for decades.

Now we are poised for a return to the Moon, with essentially the same tensions playing out. As of now there are five nations in the Moon club – those who have achieved soft landings on the Moon (crashing something into the Moon apparently doesn’t count) – the US, the Soviet Union, China, India, and Japan. We have yet to have a private company land something on the Moon, but we are getting close (this year Intuitive Machines launched a mission but did not make it to the lunar surface because of a fuel leak). What are the geopolitical, economic, commercial, technological, scientific and exploration factors pushing us back to the Moon? It’s complicated, but here are some factors that are commonly discussed by experts.

First, we are clearly in the midst of a new geopolitical space race, this time mainly between the US and China. And again, prestige and influence on the international stage is at stake. Strategists also talk of controlling cislunar space – essentially the space between the Earth and the Moon. This means having an infrastructure of rockets, capsules, and stations that can get to the Moon and back, either crewed or uncrewed. This includes positioning monitoring satellites to keep track of what’s happening in cislunar space, including near Earth orbit.

Of course I would prefer that space exploration be done entirely for scientific and commercial purposes, rather than geopolitical competition. But I don’t regret, for example, the Apollo missions because of the competition angle. I just hope that competition remains friendly. We do have an international space treaty that dictates that the no one puts nuclear weapons in space, and that no one can own the Moon. All missions there must be for the benefit of all mankind. This treaty was a reaction to fears that cold-war space competition would get ugly.

Space exploration does not have to increase international tensions. The ISS is a good example of international cooperation in space, which could help ease tensions. But it’s hard to measure the impact of this, or missions like the linkup between Apollos and Soviet era capsules.

Now there is also a much larger commercial dimension to space exploration then there was during Apollo. Private companies, like Boeing and Space X, are now providing NASA with access to the ISS, and will play a critical role in getting to the Moon and maintaining our infrastructure there. Even if we work things out on the political end, there may be an intense commercial competition for lunar resources. The US and other countries have essentially passed laws saying that private companies can benefit commercially from resources extracted from space. This is part of their plan to bolster the private space industry, making sure they have an incentive to invest in space.

What does all this mean for the next phase of Moon exploration? The fear is that we will see a competition for lunar resources. These fall into two main categories – resources for use on the Moon, and resources to be flown back to Earth. Lunar resources for the Moon include water – who gets to use that frozen ice in permanently shadowed craters near the poles? Does whoever gets there first get to monopolize those resources? Will it be legal to set up a mining operation for rare earth minerals and helium for shipping back to Earth (assuming at some point this will be commercially viable)?

Right now we lack definitive international agreements, especially among nations that have the ability to get to the Moon. Yes, according to international treaty no one can own the Moon or its resources. But also according we have those national laws that state explicitly that private companies can benefit from space, including lunar, resources. The treaties we have state mainly broad principles, and it is unclear how or even if they would apply today.

Clearly we need updated international treaties to govern how the Moon and its resources can be used by nations and private corporations. This is an opportunity, before the race kicks into high gear, to move things in the direction of fair cooperation and to mitigate the worst aspects of competition. I think friendly competition can be a good thing, spurring investment and innovation. But there needs to be rules to ensure competition is fair and peaceful and benefits everyone. We really need to get ahead of this, and not wait for something terrible to happen first.

The post The Moon Race is On first appeared on NeuroLogica Blog.

The meaning of the word "bot" on Twitter/X seems to have shifted over time, with people originally using it to flag automated accounts, but now employing it to insult people they disagree with

The Washington Post recently published an article asking if COVID-19 infection can cause cancer. Probably not, but cancer caused by a virus is more more plausible than "turbo cancer" caused by the vaccine.

The post Forget “turbo cancers” caused by COVID-19 vaccines. Does COVID itself cause cancer? first appeared on Science-Based Medicine.

Last week, the New York Times ran an op-ed by Alina Chan, Queen of lab leak conspiracy theories and then gave it a prominent place in its Sunday Magazine this weekend. How is it wrong? Let me count the ways.

The post The New York Times promotes “lab leak” conspiracy theories first appeared on Science-Based Medicine.

To date, astronomers have confirmed the existence of 5638 extrasolar planets in 4,199 star systems. In the process, scientists have found many worlds that have defied expectations. This is certainly the case regarding “hot Neptunes,” planets that are similar to the “ice giants” of the outer Solar System but orbit much closer to their stars. But when a Johns Hopkins University-led team of astronomers discovered TIC365102760 b (aka. Pheonix), they observed something entirely unexpected: a Neptune-sized planet that retained its atmosphere by puffing up.

Sam Grunblatt, an astrophysicist with JHU’s William H. Miller III Department of Physics and Astronomy, led the research. He was joined by an international team that included NSF Graduate Research Fellow Nicholas Saunders, 51 Pegasi b Fellows Shreyas Vissapragada, Steven Giacalone, Ashley Chontos, and Joseph M. Akana Murphy, as well as researchers from many prestigious institutes and universities. The paper that describes their findings (which recently appeared in The Astrophysical Journal) is part of a series titled “TESS Giants Transiting Giants.”

Artist’s impression of JG436b, a hot Neptune located about 33 light years from Earth. Credit: STScI

Puff planets are a new class of incredibly rare exoplanets, accounting for an estimated 1% of planets in our galaxy. The team discovered Pheonix by combining data from the Transiting Exoplanet Survey Satellite (TESS) with radial velocity measurements obtained by the High Resolution Echelle Spectrometer (HIRES) at the Keck Observatory. Their data indicated that Pheonix is 0.55 times the size of Jupiter but only 0.06 times as massive, which orbits a red giant star with a period of 4.21285 days (about six times closer to its star than the distance between Mercury and the Sun).

Based on the age and temperature of its star and the planet’s remarkably low density, the team expected that Pheonix’s gaseous envelopes should have been stripped away billions of years ago. Based on its density, the team also estimates that the planet is the puffiest “puff planet” discovered to date (roughly 60 times less dense than the densest “hot Neptune”) and that it will begin spiraling into its star in about 100 million years. As Grunblatt explained in a JHU HUB press release:

“This planet isn’t evolving the way we thought it would. It appears to have a much bigger, less dense atmosphere than we expected for these systems. How it held on to that atmosphere despite being so close to such a large host star is the big question.”

“It’s the smallest planet we’ve ever found around one of these red giants, and probably the lowest mass planet orbiting a [red] giant star we’ve ever seen. That’s why it looks really weird. We don’t know why it still has an atmosphere when other ‘hot Neptunes’ that are much smaller and much denser seem to be losing their atmospheres in much less extreme environments.”

Artist’s impression of Pheonix, the “hot Neptune” orbiting a red giant star 8 billion light-years from Earth. Credit: Roberto Molar Candanosa/JHU

These findings could have implications for new insight into the late-stage evolution of planetary systems and help scientists predict what will happen to the Solar System in a few billion years. According to standard models of stellar evolution, our Sun will exit its main sequence phase, expand to become a red giant, and eventually consume the inner planets. Based on these findings, they predict that Earth’s atmosphere may not evolve the way astronomers previously expected. Instead of our Sun blasting it away, our atmosphere may expand to become incredibly “puffy.”

Pheonix is the latest puffy planet examined by the international team based on TESS data. While puff planets are known to be rare, exoplanets like Pheonix are especially elusive because of their small size and low density. In the future, Grunblatt and his colleagues plan to search for more of these smaller worlds and have already identified a dozen potential candidates by combining transit and radial velocity data.

Further Reading: John Hopkins University, The Astrophysical Journal

The post Instead of Losing its Atmosphere, an Exoplanet Puffed Up and Held Onto it appeared first on Universe Today.

Here Richard Dawkins interviews linguist and author John McWhorter, a person familiar to readers of this site. And most of the 54-minute discussion is about linguistics.

It’s refreshing to hear McWhorter’s enthusiasm for linguistics, and this bit of the discussion goes from the start of the interview until about 37 minutes in. It’s sad that McWhorter has, by his own admission, been more or less drummed out of the fraternity of academic linguists because of his heterodox views on racism. I’m sure, based on this interview alone, that he was a terrific teacher.

At any rate, McWhorter explains why he began studying linguistics (it involves Hebrew), how many times he thinks language originated (McWhorter thinks just once, though he’s not convinced that this is supported by the existence of a “universal grammar” or universal “recursion”: subordinate phrases embedded within phrases). Rather, McWhorter is convinced of a single origin of language by parsimony alone. As to when it originated, McWhorter makes rather unconvincing arguments (criticized by Richard) that Homo erectus could use syntactic language; he’s on more solid ground when he thinks that Africans, because of evidence of their mental sophistication, used language around 300,000 years ago.

They discuss evidence that the FOXP2 gene was implicated in origin of language, and McWhorter is accurate in saying that this theory hasn’t worked out, though he believes, along with Steve Pinker, that the ability to use syntactic language is encoded in our genome.

The discussion of “woke racism” (the title of McWhorter’s well known book, which was originally “The Elect”) begins at 36:40.  Dawkins moves the discussion into why McWhorter considers woke racism a “religion”, even though there are no supernatural beings involved. I’m not particularly concerned whether one conceives of progressive racial activism as an ideology or a religion, for it seems a semantic question. To me the more interesting questions are the characteristics of the movement (Does it promote irrationality? Is it disconnected from reality? Does it promote “safe spaces”, which McWhorter sees as a religious concept?)

The discussion moves to the question of why you are considered black (or claim you are black) if you have any black ancestors, which leads to McWhorter’s assertion that we have to go beyond race as a personal identity.

The discussion finishes with McWhorter pushing back on the “defenestration” of figures like Thomas Jefferson because they were either slaveholders or didn’t denigrate slavery. He sees this demonization as “pernicious for education”, although he agrees that some extreme versions of racism (e.g., Woodrow Wilson) warrants taking down statues or erasing names. And what, he muses, will demonize us to our descendants.

It’s a very good discussion, I think, and shows McWhorter’s passion, eloquence, and thoughtfulness.

Since McWhorter mentions Jamaican patois as a form of English that isn’t recognizable as English, I wanted to hear some of it, so I’ve put the video showing such patois below.

h/t: Williams Garcia

The James Webb Space Telescope (JWST) has once again found evidence that the early universe was a far more complex place than we thought. This time, it has detected the signature of carbon atoms present in a galaxy that formed just 350 million years after the Big Bang – one of the earliest galaxies ever observed.

“Earlier research suggested that carbon started to form in large quantities relatively late – about one billion years after the Big Bang,” said Kavli Institute Professor Roberto Maiolino. “But we’ve found that carbon formed much earlier – it might even be the oldest metal of all.”

‘Metal’ is the name astronomers give to any element heavier than hydrogen or helium, and seeing metals like carbon so early is a surprise. Carbon is, of course, one of the building blocks of life on Earth, but it also plays a role in galaxy and solar system formation. It is one of the materials that can accumulate in the protoplanetary disks around stars, snowballing to become planets, moons, and asteroids.

But astronomers weren’t expecting to see that process happening so early.

When the first stars (called population-III stars) were born, in an era of the universe known as Cosmic Dawn, the only plentiful elements around were hydrogen and helium. All heavier elements didn’t yet exist. They were only able to form later, inside the cores of stars, therefore wouldn’t be detectable until well after the deaths of the first stars.

Dying population-III stars that explode as supernovas throw their heavier elements out into the universe, allowing future populations of stars to develop rocky planets with more interesting chemistry.

The galaxy in question, named GS-z12, is thought to contain largely second generation stars, built from the remains of those first supernovas. Astronomers didn’t expect the building blocks of the galaxy to be carbon-rich:

“We were surprised to see carbon so early in the universe, since it was thought that the earliest stars produced much more oxygen than carbon,” said Maiolino. “We had thought that carbon was enriched much later, through entirely different processes, but the fact that it appears so early tells us that the very first stars may have operated very differently.”

JWST’s Near Infrared Spectrograph allowed astronomers to break down the light coming from the distant galaxy into its constituent parts, revealing all the different wavelengths present. Every element and chemical compound has its own signature when viewed via spectroscopy, and the signal for carbon was very strong. There was also a fainter signal for neon and oxygen, though those remain tentative detections for the moment.

How carbon emerged before oxygen is an open question, but one hypothesis proposes that scientists now need to revisit their models of population-III star supernovas. If these supernovas occurred with less energy than previously thought, then they would scatter carbon from the stars’ outer shells, while most of the oxygen present would be captured within the event horizon as the stars collapsed into black holes.

Regardless of how it happened, there is now a strong case for heavy elements early in the universe – far earlier than anyone guessed. JWST is revealing unexpected details about the first galaxies that will ultimately make scientists’ predictions about the evolution of the universe far more robust. And perhaps most significantly, it also tells us about the very first step towards creating life.

“These observations tell us that carbon can be enriched quickly in the early universe,” said Francesco D’Eugenio of the Kavli Institute. “And because carbon is fundamental to life as we know it, it’s not necessarily true that life must have evolved much later in the universe. Perhaps life emerged much earlier – although if there’s life elsewhere in the universe, it might have evolved very differently than it did here on Earth.”

Learn More:

“Earliest detection of metal challenges what we know about the first galaxies.” University of Cambridge.

D’Eugenio et al. “JADES: Carbon enrichment 350 Myr after the Big Bang in a gas-rich galaxy.” ArXiv preprint (accepted to Astronomy & Astrophysics).

The post Carbon is Surprisingly Abundant in an Early Galaxy appeared first on Universe Today.

If were are supposed to be indifferent to the deaths of young people because "hardly any" died, and we are supposed to be indifferent to the deaths of older people because "their time to death in general is not that long," which of the 1.1 million COVID deaths should we care about?

The post “This Thing Has Killed Less Than Or About As Many As Flu Would Kill In A Normal Year In Kids, I Say Hardly Any” & “80-Year-Olds, Their Time To Death In General Is Not That Long.” first appeared on Science-Based Medicine.

Quickie with Bob - Drake Equation; News Items: Chang-e-6 Lifts Off from Moon, Adaptogens, Younger Menarche, More Aliens, Metasurface Night Vision; Who's That Noisy; Your Questions and E-mails: Megabits and Ancient Pyramids; Science or Fiction

There are likely millions of “rogue” or free-floating planets (FFPs) spread through the galaxy. These planets, which aren’t big enough to become stars but also aren’t beholden to a star’s gravity, are some of the hardest objects for astronomers to spot, as they don’t give off their own light, and can only be seen when they cross in front of something that does give off its own light. Enter Euclid, a space telescope that launched last year. Its primary mission is to observe the universe’s history, but a new paper describes an exciting side project – finding FFPs in Orion.

In particular, it is finding FFPs around a system known as Sigma Orionis. Famously located on the eastern side of Orion’s Belt, this “star” is a system of at least five different stars, all gravitationally bound in one way or another, forming what is known as a “cluster.” It’s also surrounded by a “dust wave” of particles pointing at the nearby Horsehead Nebula, all of which lends itself to being a place where it would be easy to find FFPs. 

Free-floating planets of this type can also be considered “failed stars” as they did not have enough mass to start the fusion process that comes with star formation. This isn’t the first time they’ve been found in star-forming regions. Other FFPs have been found in NGC 1333, Collider 69, and even the Orion Nebula. This isn’t even the first time they’ve been found in Sigma Orionis – but it is the first time they’ve been detected with the accuracy Euclid allows. As the paper’s authors put it, they “appear to be ubiquitous and numerous.”

Fraser interviews Dr. Maggie Lieu about Euclid and its capabilities

So, what’s unique about what Euclid did? Admittedly, the paper was a sort of test run for the telescope. The observations were taken back in October, only a few months after it launched in the middle of 2023. Those observations also focused on regions well known to contain tons of FFPs already. So what did it find?

They found a bunch of much smaller FFPs than had previously been found. Astronomers use an algorithm called the Initial Mass Function (IMF) to describe the number of stars of specific sizes that would be formed. FFPs define the lower limit of that IMF – i.e., if an object isn’t big enough to become a star, it becomes an FFP. Sufficiently smaller FFPs help astronomers define the limits of the IMF in certain regions, but so far, they have escaped the notice of less sensitive detectors.

That’s where Euclid comes in. The authors point out how the lower end of the IMF is not well defined and describe how the data collected by Euclid could be used to flesh out models at the lower end of the spectrum. However, they also point out that this is still very early in Euclid’s data collection cycle, and plenty more systems could prove exciting hunting grounds for smaller FFPs than have ever been seen before.

Fraser discusses rogue planets in the Orion Nebula

For now, though, this is an excellent first test case of Euclid’s capabilities. Given the sheer number of objects that could be floating out there in the void, it will have plenty of other opportunities to find more, and it has already started looking in several other well-known places, according to the paper. It’s got more than five years left on its planned mission duration, so there will undoubtedly be more papers describing many more FFPs in the future.

Learn More:
Martín et al – Euclid: Early Release Observations – A glance at free-floating new-born planets in the ? Orionis cluster
UT – Enjoy Five New Images from the Euclid Mission
UT – Euclid Begins its 6-Year Survey of the Dark Universe
UT – Phew, De-Icing Euclid’s Instruments Worked. It’s Seeing Better Now

Lead Image:
Multi-color mosaic of the Euclid pointing studied in this work. The area covered is 0.58 square degrees
Credit – Martín et al

The post Euclid is Finding Free Floating Planets in Orion Too appeared first on Universe Today.

It should not be surprising that Venus is dry. It is famous for its hellish conditions, with dense sulphurous clouds, rains of acid, atmospheric pressures comparable to a 900 meter deep lake, and a surface temperature high enough to melt lead. But it’s lack of water is not just a lack of rain and oceans: there’s no ice or water vapour either. Like Earth, Venus is found within our Solar System’s goldilocks zone, so it would have had plenty of water when it was first formed. So where did all of Venus’s water go?

Venus is an extremely dry planet, although it wasn’t always like this. At some point in its history, a run-away greenhouse effect began, ending with its current extreme state. Most models agree that this process would have driven off most of its original water, but that there should still be some remaining. And yet, observations show us that there is practically no water at all. Planetary scientists at the University of Colorado Boulder believe that they have found an explanation: a molecule called HCO+ high in Venus’s atmosphere may be responsible. Unfortunately, they may have to wait for future missions to Venus before they can confirm it.

Until the middle of the 20th century, Venus was thought of as Earth’s twin. Both planets are approximately the same size and mass, and they’re both within the sun’s habitable zone – the region where temperatures can exist that are warm enough to melt ice, but not so hot that water boils into steam. It was long assumed that, beneath its shining white cloud cover, Venus must have a similar climate to Earth. Science fiction authors even wrote stories about visitors to Venus exploring verdant jungles and meeting exotic civilizations. But the truth is much harsher: Venus is an extreme place, with sulphuric acid rains, crushing atmospheric pressure, and a surface temperature hot enough to melt lead. But it wasn’t always like that.

The general assumption among astronomers and planetary scientists is that both Earth and Venus started life with similar amounts of water. But something happened to release enormous quantities of carbon dioxide into its atmosphere, leading to an extreme runaway greenhouse effect. The high temperatures melted off any ice, and boiled away any liquid water, filling the atmosphere with water vapour. Much of this hot vapour would eventually blow off into space, drying out the planet, but some should remain. The puzzle is that the usual models predict a great deal more remaining water vapour than what is actually there. So, what happened?

According to a study, led by Dr Eryn Cangi and Dr Mike Chafin, both of the Laboratory for Atmospheric and Space Physics (LASP), the answer may be a molecule named HCO+. In their earlier work studying the atmosphere of Mars, they discovered a process by which this molecule can remove water from planetary atmospheres. In their new paper, they suggest that the same process could be at work on Venus. The only catch is that this molecule has never been detected in the Venusian atmosphere.

Unfortunately, there is little evidence to confirm this theory. HCO+ has never been detected in the atmosphere of Venus. However, Cangi and Chafin point out that this is because nobody has ever looked for it, and none of the missions sent to Venus so far were equipped with instruments that could detect it. They are optimistic for future missions, however.

Illustration of NASA’s DAVINCI probe falling to the surface of Venus. (Credit: NASA GSFC visualization by CI Labs Michael Lentz and others)

“One of the surprising conclusions of this work is that HCO+ should actually be among the most abundant ions in the Venus atmosphere,” says Chaffin.
“There haven’t been many missions to Venus,” adds Cangi. “But newly planned missions will leverage decades of collective experience and a flourishing interest in Venus to explore the extremes of planetary atmospheres, evolution and habitability.”

The planetary science community has gotten increasingly interested in Venus, and a number of future missions are planned to study it in more detail. NASA’s planned Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission is one example. DAVINCI will drop a probe down to the surface, which will study the atmosphere at different altitudes as it falls. Unfortunately for Cangi and Chafin, it is not designed specifically to look for HCO+, but it may reveal other clues to either confirm or disprove their theory. But they remain optimistic that additional missions will be sent in future that will carry the necessary instruments that they can use to test their work.

For more information, visit CU Boulder’s announcement at https://www.colorado.edu/today/2024/05/06/venus-has-almost-no-water-new-study-may-reveal-why

The post Where Did Venus's Water Go? appeared first on Universe Today.

https://traffic.libsyn.com/secure/sciencesalon/mss438_Marc_Hauser_2024_06_08.mp3 Download MP3

Each year at least a billion children around the world are victims of adverse childhood experiences (ACEs) that range from physical abuse and racial discrimination to neglect and food deprivation. The brain plasticity of our most vulnerable makes the adverse effects of trauma only that much more damaging to mental and physical development. Those dealt a hand of ACEs are more likely to drop out of school, have a shorter life, abuse substances, and suffer from myriad mental health and behavioral issues.

The crucial question is: How do we intervene to offer these children a more hopeful future? Neurobiologist and educator Dr. Marc Hauser provides a novel, research-based framework to understand a child’s unique response to ACEs that goes beyond our current understanding and is centered around the five Ts—the timing during development when the trauma began, its type, tenure, toxicity, and how much turbulence it has caused in a child’s life. Using this lens, adults can start to help children build resilience and recover—and even benefit—from their adversity through targeted community and school interventions, emotional regulation tools, as well as a new frontier of therapies focused on direct brain stimulation, including neurofeedback and psychedelics.

While human suffering experienced by children is the most devastating, it also presents the most promise for recovery; the plasticity of young people’s brains makes them vulnerable, but it also makes them apt to take back the joy, wonder, innocence, and curiosity of childhood when given the right support. Vulnerable Minds is a call to action for parents, policymakers, educators, and doctors to reclaim what’s been lost and commit ourselves to our collective responsibility to all children.

Marc Hauser is an educator, neuroscientist, and the founder of Risk Eraser, a program that helps at-risk kids lead healthier lives. He is a former professor of evolutionary biology and psychology at Harvard University and the author of over three hundred papers. His books include Wild Minds: What Animals Really Think, Moral Minds: The Nature of Right and Wrong, Evilicious: Cruelty = Desire + Denial, and his new book Vulnerable Minds: The Harm of Childhood Trauma and the Hope of Resilience.

Shermer and Hauser discuss:

• Hauser’s personal adversities, from childhood bullying to academic misconduct at Harvard
• LJ: LeBron James story from childhood trauma to NBA triumph
• WHO: a billion children annually suffer from ACEs
• Types of adversity: physical and sexual abuse, racial and sexual discrimination, emotional and physical deprivation, domestic violence, disease, neglect, cruelty, torture, war
• ACEs: Adverse Childhood Experiences
• DSM-5: limited prosocial emotions/callous-unemotional: a highly heritable trait
• Psychopathy, Machiavellianism, Narcissism: the Dark Triad
• Attachment Theory: John Bolby
• Disorganized Attachment: when attachment is broken: hyperactive amygdala: reach puberty at an earlier age, have heightened sexual activity, less investment in offspring (even 3 generations later)
• Borderline Personality Disorder: (1) a pervasive pattern of instability of interpersonal relationships, self-image, and affects, and (2) marked impulsivity beginning by early adulthood and present in a variety of contexts.
• Sexual abuse and eating disorders
• Consequences: substance abuse, suicide, obesity, depression, liver disease, school dropout, lower life expectancy
• Do different types of ACEs result in different consequences?
• Why some people meet traumatic experiences with resilience while others don’t?
• Timing, duration, severity, and predictability of ACEs.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

I’ve seen some pretty incredible things using my eyes.. First off of course, is the stunning sight of a dark star filled sky, then there is the incredible sight of the Andromeda Galaxy 2.5 million light years away. Planets too can of course be seen as they slowly move across the sky but it’s a little more unusual to see something that reminds us the Universe changes. Well, we have an opportunity  in just a few weeks time. The star T Corona Borealis (T CrB) will brighten about 1,500 times so it can be seen with the unaided eye. Miss it though and you will have to wait another 80 years!

It’s always exciting to see something new in the sky. It doesn’t happen all that often but when it does, well it’s definitely an opportunity to get out and enjoy the show. The event is a nova which translates from Latin meaning new. In astronomy, we talk of nova as a number of different phenomena which herald the appearance of something new which is visible in the sky. A supernova is a well known example marking a colossal stellar explosion.

In the case of TCrB it refers to a binary star system where a white dwarf star (the remains of a star like the Sun) is in orbit around another star. I should clarify that statement, they both orbit around a common centre of gravity. At a distance of 3,000 light years, it is one of the closest of its type and so when it goes into outburst, we will get to see it without  any telescope or binoculars, just the ‘Mark-1 eyeball.’ 

The process that leads to the sudden brightening is really quite fascinating. The white dwarf star is a much higher pull of gravity compared to its companion. As a result, it drags material from its stellar neighbour in a process known as accretion. Over time – and in the case of T CrB it takes about 80 years – hydrogen builds up on the white dwarf. The layer of hydrogen is heated up by the white dwarf causing it to heat to critically high temperatures, high enough to initiate hydrogen fusion. The layer of hydrogen detonates and gets ejected from the white dwarf in a brightly glowing, hot shell. Here on Earth, we see this as a sudden brightening of a previously rather inconspicuous star that would ordinarily need a telescope to see.

Nova are generally quite unpredictable, usually occurring once and often leading to the death of a star but in this case, it occurs every 80 years. We call this event a recurrent nova. Its outburst was first seen in 1866 by an astronomer called John Birmingham who, amusingly came from Ireland and not Birmingham. It was seen again in 1946 when there was a drop in brightness before the explosion and it is this drop in brightness that has just been observed over the last couple of months. 

This all points to the next nova event being imminent, perhaps just a month or two away so, if you like me, are keen to see this once in a lifetime event then it’s time to get your coat on and get outside. Unfortunately, because we don’t know exactly when it is going to occur the best approach is to simply become familiar with the sky in the region of the constellation Corona Borealis. 

Alphecca is the brightest star in a C-shaped pattern of stars: the constellation Corona Borealis. It’s near the bright star Arcturus on the sky’s dome. Credit: EarthSky

Thankfully, Corona Borealis is in a fairly ‘quiet’ part of the sky with not too many bright stars. To find it from where you are then use an app on a smartphone to locate Vega in Lyra and Arcturus in Bootes, Corona Borealis is approximately between the two and looks somewhat like a semicircle of stars. Get to know that part of the sky and become familiar with the stars visible to the naked eye. Keep watching over the weeks and months ahead (and of course keep an eye on Universe Today) and at some point soon, you will see a ‘new’ star appear just outside the semicircle. 

Good luck and clear skies. 

Source : Keep your eyes on the sky for a new star as “once in a lifetime” cosmic explosion looms

The post We’re Now Just Weeks Away from a Stellar Explosion You Can See With Your Own Eyes appeared first on Universe Today.

We live in a Universe studded with black holes. Countless stellar mass and supermassive ones exist in our galaxy and most others. It’s likely they existed as so-called “primordial” black holes in the earliest epochs of cosmic history. Yet, there seems to be a missing link category: intermediate-mass black holes (IMBH). Astronomers have searched for these rare beasts for years and there’s only one possible observation thanks to gravitational-wave data. So, where are they?

IMBH might be hidden away in the hearts of globular clusters. But, given the tightly packed nature of those compact collections of stars, how would we know if they contained any IMBH? Teams of researchers in Japan and China came up with a couple of ways to search them out. One is to look for fast-moving stars ejected from globular clusters. The other is to do simulations of collisions of stars in the hearts of newly forming clusters. Both methods may point the way to more IMBH discoveries.

What Are Intermediate-mass Black Holes?

These rare objects are pretty much what their name says: black holes with masses somewhere between their stellar-mass cousins and the supermassive behemoths at the hearts of galaxies. They can contain as little as a thousand times the mass of the Sun, which would be fairly “small”, up to maybe a million solar masses. Beyond that are the supermassive monsters with millions or billions of times the mass of the Sun. The IMBH don’t come from supernova explosions, since there’s no massive star big enough to collapse to produce an IMBH. The birth of an IMBH should involve multiple massive objects coalescing together. This makes them more like their big supermassive black hole siblings.

So, where would such a collisional event happen? It would help if you had a dense agglomeration of stars tightly packed together. That describes globular clusters to a T. They’re crowded with stars, and likely have a good collection of very massive ones. Those are the stars that explode as supernovae and collapse down to produce a stellar-mass black hole. If enough of them exist in the cluster, they could merge and create an IMBH. Another suggestion to create an IMBH is for massive stars to collide to create a single more-massive object.

Many globular clusters orbit the core of the Milky Way Galaxy. Some of the densest ones have millions of stars pulled together by gravity. The cluster Messier 15 (M15) is a good example. It contains more than 100,000 stars crammed into an area of space about 175 light-years across. If runaway star collisions or stellar-mass black hole mergers occurred in M15, that could be enough to create an IMBH.

Simulating Globular Clusters and Intermediate-Mass Black Hole Growth

Another idea is to explore the formation of globulars to see if it produces any clues to the origins and existence of IMBH. That’s what a team of scientists at the University of Tokyo did. They created advanced simulations of star cluster formation to see if massive-star collisions could occur and lead to the birth of IMBH. It’s not an easy task. Previous simulations suggested stellar winds would blow away the needed masses to create these missing black holes.

“Star cluster formation simulations were challenging because of the simulation cost,” said team leader Michiko Fujii. “We, for the first time, successfully performed numerical simulations of globular cluster formation, modeling individual stars. By resolving individual stars with a realistic mass for each, we could reconstruct the collisions of stars in a tightly packed environment. For these simulations, we have developed a novel simulation code, in which we could integrate millions of stars with high accuracy.”

A simulated star cluster forming in a giant molecular cloud. Could this visualization help astronomers understand the formation of intermediate-mass black holes in clusters? Courtesy: Takaaki Takeda (VASA Entertainment, Inc.)

The resulting simulation run showed that runaway collisions brought very massive stars together. These are perfect candidates to end up as IMBH candidates. “Our final goal is to simulate entire galaxies by resolving individual stars,” Fujii points to future research. “It is still difficult to simulate Milky Way-size galaxies by resolving individual stars using currently available supercomputers. However, it would be possible to simulate smaller galaxies such as dwarf galaxies. We also want to target the first clusters, star clusters formed in the early universe. First clusters are also places where IMBHs can be born.”

Runaway Stars and IMBH

Okay, so simulations show that such IMBH could be possible in the globular cluster environment, but what’s the physical proof they actually exist? No one has actually detected the collisions of stellar-mass black holes inside a cluster to create an IMBH. Nor have they seen stellar collisions that might create a monster object — although the Japanese simulations proved they can happen. The trick now is to observe both types of event. Until that happens, astronomers can figure out if IMBH exist through indirect means.

A Chinese research team, led by Yang Huang of the University of the Chinese Academy of Sciences, recently posted a paper about a high-velocity star fleeing the scene of a collision in the heart of Messier 15. The star, called J0731+3717, was ejected by an encounter with an intermediate-mass black hole embedded very close to the center of the cluster.

J0731+3717 got tossed out on its high-speed journey about 21 million years ago. The team examined its metallicity (that is, its ratios of hydrogen and heavier elements (called “metals” by astronomers)) and found that it matches the stars in M15. The rogue star moves away from the cluster at a velocity of about 550 kilometers per second and once “lived” at a distance of about 1 AU from the cluster’s core. The team analyzed those measurements and did reverse orbital calculations of that star (and others within 5 kpc of the Sun). Based on their calculations, they concluded the star had a too-close encounter with an intermediate-mass black hole containing about 100 solar masses.

The team suggests that this method be used to prove the existence of other IMBH in similar environments. They conclude their paper with a look at future observations to prove the concept. “With the increasing power of ongoing Gaia and large-scale spectroscopic surveys, we expect to discover dozens of cases within the 5kpc volume and ten times more within a 10kpc volume, which should shed light on the understanding of the evolutionary path from stellar-mass BHs to SMBHs.”

For More Information

Simulations Yield New Intermediate Mass Black Holes Recipe
Medium and Mighty: Intermediate-mass Black Holes Can Survive in Globular Clusters
A High-velocity Star Recently Ejected by an Intermediate-mass Black Hole in M15

The post Globular Clusters Should Contain More Intermediate-mass Black Holes appeared first on Universe Today.

The United States has enough biomass potential to produce 35 billion gallons per year of aviation biofuel by 2050, a new report confirms.

Odysseus, a tenacious lander built by the company Intuitive Machines, almost didn't make it to the moon. But an experiment aboard the spacecraft managed to capture an image of Earth as it might look to observers on a planet far from our own.

Researchers have provided a simple and comprehensive -- if less dramatic -- explanation for bright radar reflections initially interpreted as liquid water beneath the ice cap on Mars' south pole.

Scientists used CRISPR/Cas9 to increase gene expression in rice by changing its upstream regulatory DNA. While other studies have used the technology to knock out or decrease the expression of genes, this study, is an unbiased gene-editing approach to increase gene expression and downstream photosynthetic activity. The approach is more difficult than transgenic breeding, but could potentially preempt regulatory issues by changing DNA already within the plant, allowing the plants to get in the hands of farmers sooner.