Astronomy and Planetary Science Thread

[Flyaway]

About 66 million years ago, an estimated 6-mile-wide (9.6 kilometers) object slammed into Earth, triggering a cataclysmic series of events that resulted in the demise of non-avian dinosaurs.

Now, scientists think they know where that object came from.

According to new research, the impact was caused by a giant dark primitive asteroid from the outer reaches of the solar system's main asteroid belt, situated between Mars and Jupiter. This region is home to many dark asteroids — space rocks with a chemical makeup that makes them appear darker (reflecting very little light) compared with other types of asteroids.

Simulating over hundreds of millions of years, the model showed thermal forces and gravitational tugs from planets periodically slingshotting large asteroids out of the belt. On average, an asteroid more than 6 miles wide from the outer edge of the belt was flung into a collision course with Earth once every 250 million years, the researchers found. This calculation makes such an event five times more common than previously thought and consistent with the Chicxulub crater created just 66 million years ago, which is the only known impact crater thought to have been produced by such a large asteroid in the last 250 million years. Furthermore, the model looked at the distribution of "dark" and "light" impactors in the asteroid belt and showed half of the expelled asteroids were the dark carbonaceous chondrites, which matches the type thought to have caused Chicxulub crater.

Origin of dinosaur-ending asteroid possibly found. And it's dark.

Scientists figured out what slammed into Earth and killed the dinosaurs 66 million years ago: a giant dark primitive asteroid from the outer reaches of the solar system's main asteroid belt.

www.livescience.com

 

[Flyaway]

The recurrent nova RS Ophiuchi (RS Oph), located in the constellation of Ophiuchus, is in a rare outburst, its first for more than 15 years. RS Oph brightened rapidly on 8 August 2021 from around magnitude +12 to shine presently at about magnitude +4.8, a 600-fold in just a day. This is its first outburst since February 2006 and only five other eruptions have been observed since 1898.

RS Ophiuchi in a rare outburst to naked-eye visibility – Astronomy Now

astronomynow.com

 

[Flyaway]

An international team of astronomers using data from NASA’s Juno spacecraft, the W.M. Keck Observatory and Japan’s Hisaki satellite was able to nail down the source of Jupiter’s surprising temperature, reporting their findings in the journal Nature.

“We found that Jupiter’s intense aurora, the most powerful in the solar system, is responsible for heating the entire planet’s upper atmosphere to surprisingly high temperatures,” said James O’Donoghue of the JAXA Institute of Space and Astronautical Science in Sagamihara, Japan.

View: https://youtu.be/pXTpL3DA6yY

Jupiter’s high temperature traced to planet’s powerful auroras – Astronomy Now

astronomynow.com

 

[Flyaway]

Rings around a black hole from X-ray echoes off interstellar dust

Some 7,800 light years from Earth, a black hole is actively sucking in material from a companion star with about half the mass of the Sun. The material forms a disc around the black hole, glowing in X-rays as particles crash together in a swirling inferno. The binary system is known as V404 Cygni and on 5 June 2015, the Swift space telescope detected an X-ray outburst that created a spectacular ring of “light echoes” as the high-energy radiation bounced off intervening clouds of smoke-like interstellar dust. In the composite image below, observations by the Chandra X-ray Telescope (shown in blue) were combined with optical imagery from the Pan-STARRS telescope in Hawaii. Eight concentric X-ray echoes can be seen as radiation reflects off dust at different distances.

Rings around a black hole from X-ray echoes off interstellar dust – Astronomy Now

astronomynow.com

 

[Flyaway]

Saturn’s core is a big, diffuse, rocky slushball

The process should leave planets like Jupiter and Saturn with a solid, rocky core buried deep within the envelope of gas. But confirming that core composition has been difficult. Now, researchers have used features in Saturn's rings to detect subtle gravitational influences from the core. While not definitive, the results suggest that the core is large, and the solid, rocky portion is widely spread out across that area.

The new work relies on the features of the waves we've detected within Saturn's rings. In essence, the researchers built multiple models of what Saturn's core could look like and check whether the models would create the patterns we actually see. The real-world data is then used to put constraints on the possible elements of Saturn's core.

Overall, the models that fit the data place Saturn's core-envelope boundary a significant distance from the planet's center, roughly 60 percent of the way to the surface. That's a radius of nearly 60,000 kilometers, or over nine times Earth's radius.
The exact composition of the core is much harder to figure out, since the constraints are fairly wide. The total mass of heavier elements in the core is about 19 times Earth's mass, consistent with models of gas-giant formation that place rock and iron at the center, although a lot of this material could also be water ice. Yet the total mass of the core could be as high as 55 times the Earth's mass, indicating that there's a lot of other material there—likely metallic hydrogen and helium.

Saturn’s core is a big, diffuse, rocky slushball

There are still uncertainties, but data from the rings rules out a layered model.

arstechnica.com

A diffuse core in Saturn revealed by ring seismology

Abstract
The best constraints on the internal structures of giant planets have historically originated from measurements of their gravity fields1,2,3. These data are inherently mostly sensitive to a planet’s outer regions, stymieing efforts to measure the mass and compactness of the cores of Jupiter2,4,5 and Saturn6,7. However, studies of Saturn’s rings have detected waves driven by pulsation modes within the planet8,9,10,11, offering independent seismic probes of Saturn’s interior12,13,14. The observations reveal gravity-mode pulsations, which indicate that part of Saturn’s deep interior is stable against convection13. Here, we compare structural models with gravity and seismic measurements from Cassini to show that the data can only be explained by a diffuse, stably stratified core–envelope transition region in Saturn extending to approximately 60% of the planet’s radius and containing approximately 17 Earth masses of ice and rock. This gradual distribution of heavy elements constrains mixing processes at work in Saturn, and it may reflect the planet’s primordial structure and accretion history.

A diffuse core in Saturn revealed by ring seismology - Nature Astronomy

Like a seismograph, Saturn’s rings are sensitive to oscillations coming from the planet’s interior. State-of-the-art modelling shows that Cassini’s measurements of ring waves point to a convectively stable diffuse core within Saturn, which extends for 60% of its radius and contains 17 Earth...

www.nature.com

 

[Flyaway]

Cool Worlds - Could Origami Be The Key to Detecting Exomoons?

View: https://youtu.be/2sXTNfU5pHc

Transit Origami: A Method to Coherently Fold Exomoon Transits in Time Series Photometry

One of the simplest ways to identify an exoplanetary transit is to phase fold a photometric time series upon a trial period - leading to a coherent stack when using the correct value. Such phase-folded transits have become a standard data visualisation in modern transit discovery papers. There is no analogous folding mechanism for exomoons, which would have to represent some kind of double-fold; once for the planet and then another for the moon. Folding with the planet term only, a moon imparts a small decrease in the surrounding out-of-transit averaged intensity, but its incoherent nature makes it far less convincing than the crisp stacks familiar to exoplanet hunters. Here, a new approach is introduced that can be used to achieve the transit origami needed to double fold an exomoon, in the case where a planet exhibits TTVs. This double fold has just one unknown parameter, the satellite-to-planet mass ratio, and thus a simple one-dimensional grid search can be used to rapidly identify power associated with candidate exomoons. The technique is demonstrated on simulated light curves, exploring the breakdown limits of close-in and/or inclined satellites. As an example, the method is deployed on Kepler-973b, a warm mini-Neptune exhibiting an 8 minute TTV, where the possibility that the TTVs are caused by a single exomoon is broadly excluded, with upper limits probing down to a Ganymede-sized moon.

[2108.02903] Transit Origami: A Method to Coherently Fold Exomoon Transits in Time Series Photometry

 

[Flyaway]

Interstellar objects outnumber Solar system objects in the Oort cloud

ABSTRACT
Here, we show that the detection of Borisov implies that interstellar objects outnumber Solar system objects in the Oort cloud, whereas the reverse is true near the Sun due to the stronger gravitational focusing of bound objects. This hypothesis can be tested with stellar occultation surveys of the Oort cloud. Furthermore, we demonstrate that ∼1 per cent
of carbon and oxygen in the Milky Way Galaxy may be locked in interstellar objects, implying a heavy element budget for interstellar objects comparable to the heavy element budget of the minimum mass Solar nebula model. There is still considerable uncertainty regarding the size distribution of the interstellar objects.

Interstellar objects outnumber Solar system objects in the Oort cloud

ABSTRACT. Here, we show that the detection of Borisov implies that interstellar objects outnumber Solar system objects in the Oort cloud, whereas the rever

academic.oup.com

 

[Flyaway]

Belatedly Habitable Planets

Abstract
Stars do not remain static, so their habitable zones evolve in time. Over a star's evolution, its habitable zone encompasses new planets, and it remains uncertain whether these planets can become habitable. We refer to this often overlooked class of planets as lying in the belatedly habitable zone, and stress that many planets found in the habitable zones of other stars will belong to this class. Future studies should take belated habitability into account and not implicitly assume that these planets are habitable.

Radware Bot Manager Captcha

 

[Flyaway]

“Anomalous Stellar Acceleration: Causes and Consequences,” JBIS Vol. 74 (2021), pp. 269-275

Abstract:

As a successor to Hipparcus, an earlier European Space Agency (ESA) space telescope, the ESA Gaia space telescope was launched in December 2013 and is currently on-station at the Earth-Sun L2 Lagrange point, about 1.5 x 106km from Earth. The goal of this mission is accurate determination of position and motions for ~1 billion stars in the Milky Way galaxy [1].

Anomalous Stellar Acceleration: Causes And Consequences – BIS Shop

bis-space.com

 

[Rhinocrates]

Release:

New class of habitable exoplanets 'a big step forward' in search for life | University of Cambridge

www.cam.ac.uk

The researchers have identified a new class of habitable planets, dubbed ‘Hycean’ planets – ocean-covered planets with hydrogen-rich atmospheres – which are more numerous and observable than Earth-like planets.

At arXiv:

[2108.10888] Habitability and Biosignatures of Hycean Worlds

We investigate a new class of habitable planets composed of water-rich interiors with massive oceans underlying H2-rich atmospheres, referred to here as Hycean worlds. With densities between those of rocky super-Earths and more extended mini-Neptunes, Hycean planets can be optimal candidates in the search for exoplanetary habitability and may be abundant in the exoplanet population. We investigate the bulk properties (masses, radii, and temperatures), potential for habitability, and observable biosignatures of Hycean planets. We show that Hycean planets can be significantly larger compared to previous considerations for habitable planets, with radii as large as 2.6 Earth radii (2.3 Earth radii) for a mass of 10 Earth masses (5 Earth masses). We construct the Hycean habitable zone (HZ), considering stellar hosts from late M to sun-like stars, and find it to be significantly wider than the terrestrial-like HZ. While the inner boundary of the Hycean HZ corresponds to equilibrium temperatures as high as ~500 K for late M dwarfs, the outer boundary is unrestricted to arbitrarily large orbital separations. Our investigations include tidally locked `Dark Hycean' worlds that permit habitable conditions only on their permanent nightsides and `Cold Hycean' worlds that see negligible irradiation. Finally, we investigate the observability of possible biosignatures in Hycean atmospheres. We find that a number of trace terrestrial biomarkers which may be expected to be present in Hycean atmospheres would be readily detectable using modest observing time with the James Webb Space Telescope (JWST). We identify a sizable sample of nearby potential Hycean planets that can be ideal targets for such observations in search of exoplanetary biosignatures.

 

[Flyaway]

Fastest-moving asteroid flies closer to Sun than Mercury

Astronomers using the 570-megapixel Dark Energy Camera have found the fastest-moving asteroid yet discovered, a 1-kilometre-wide (0.6-mile-wide) body that crosses the orbits of Venus and Mercury and passes within just 20 million kilometres (12 million miles) of the Sun every 113 days. The asteroid, catalogued as 2021 PH27, heats up to almost 500 Celsius (about 900 Fahrenheit) during close approach, hot enough to melt lead.

The asteroid, catalogued as 2021 PH27, may have originated in the main asteroid belt between Mars and Jupiter, subsequently dislodged by gravitational interactions with the inner planets. But its orbit is tilted 32 degrees to the Sun’s equatorial plane, indicating it could be an extinct comet that ended up in a short-period orbit after passing by a terrestrial planet.

Fastest-moving asteroid flies closer to Sun than Mercury – Astronomy Now

astronomynow.com

 

[Flyaway]

A quarter of Sun-like stars eat their own planets, according to new research

The relatively calm history of our Solar System has favoured the flourishing of life here on Earth. In the search for alien worlds that may contain life, we can narrow down the targets if we have a way to identify systems that have had similarly peaceful pasts.

Our international team of astronomers has tackled this issue in research published in Nature Astronomy. We found that between 20% and 35% of Sun-like stars eat their own planets, with the most likely figure being 27%.

A quarter of Sun-like stars eat their own planets, according to new research

By studying the chemical makeup of binary stars, astronomers found many planetary systems are far less peaceful than ours.

theconversation.com

Here’s the related paper:

Chemical evidence for planetary ingestion in a quarter of Sun-like stars

Abstract
Stellar members of binary systems are formed from the same material, and therefore they should be chemically identical. However, recent studies have unveiled chemical differences between the two members of binary pairs composed of Sun-like stars. These chemically inhomogeneous binaries represent one of the most contradictory examples in stellar astrophysics and a source of tension between theory and observations. It is still unclear whether the abundance variations are the result of inhomogeneities in the protostellar gas clouds or are due to planet engulfment events that occurred after the stellar formation. The former scenario undermines the general belief that the chemical makeup of stars provides the fossil information of the environment in which they formed, whereas the second scenario would shed light on the possible evolutionary paths of planetary systems. Our study provides compelling evidence in favour of the planet engulfment scenario. We also establish that planet engulfment events occur in Sun-like stars with a 20–35% probability. Therefore, an important fraction of planetary systems undergo very dynamical evolutionary paths that critically modify their architectures, unlike our calm Solar System. This study opens the possibility of using chemical abundances of stars to identify which ones are the most likely to host Solar System analogues.

Chemical evidence for planetary ingestion in a quarter of Sun-like stars - Nature Astronomy

Chemical inhomogeneities between the two members of a binary star system, where the stars presumably are formed from the same material, could be due to planetary engulfment. Such a fate has befallen planets around a quarter of Sun-like (in temperature and surface gravity) stars, according to...

www.nature.com

 

[Flyaway]

Radio evidence of a stellar merger

Core collapse supernovae occur when a massive star exhausts its fuel and explodes. Theorists have predicted that a similar explosion could occur if an evolved massive star merges with a compact companion, such as a neutron star. Dong et al. have identified a radio source that was not present in earlier radio surveys. Follow-up radio and optical spectroscopy show that it is an expanding supernova remnant slamming into surrounding material, probably ejected from the star centuries before it exploded. An unidentified x-ray transient occurred at a consistent location in 2014, suggesting an explosion at that time that produced a jet. The authors suggest that the most likely explanation is a merger-triggered supernova. —KTS

Science | AAAS

www.science.org

Source: https://www.eurekalert.org/news-releases/927166

 

[Flyaway]

First time we’ve had an update in this planet nine business in what feels like ages.

Planet 9 may be closer and easier to find than thought—if it exists
A new study's "treasure map" suggests that a planet several times more massive than Earth could be hiding in our solar system, camouflaged by the bright strip of stars that make up the Milky Way.

Planet 9 may be closer and easier to find than thought—if it exists

A new study's "treasure map" suggests that a planet several times more massive than Earth could be hiding in our solar system, camouflaged by the bright strip of stars that make up the Milky Way.

www.nationalgeographic.com

Here’s the new paper:

https://arxiv.org/pdf/2108.09868.pdf

 

[Grey Havoc]

We already have a Planet 9, Pluto, even if it is currently 'unpersoned', in a manner of speaking.

 

[Deleted member 2278]

We already have a Planet 9, Pluto, even if it is currently 'unpersoned', in a manner of speaking.

Can we double-like a post? First victim of cancel culture! Content enough for Eris, Sedna et al to be dwarf planets but would personally have "grandfathered in" Pluto.

Pluto was a planet for quite some time. I don't think that history should be discarded so lightly!

 

[Flyaway]

The Enigmatic Brown Dwarf WISEA J153429.75-104303.3 (a.k.a. "The Accident")

Abstract
Continued follow-up of WISEA J153429.75−104303.3, announced in Meisner et al., has proven it to have an unusual set of properties. New imaging data from Keck/MOSFIRE and HST/WFC3 shows that this object is one of the few faint proper motion sources known with J − ch2 >8 mag, indicating a very cold temperature consistent with the latest known Y dwarfs. Despite this, it has W1−W2 and ch1−ch2 colors ∼1.6 mag bluer than a typical Y dwarf. A new trigonometric parallax measurement from a combination of WISE, Spitzer, and HST astrometry confirms a nearby distance of ${16.3}_{-1.2}^{+1.4}$ pc and a large transverse velocity of 207.4 ± 15.9 km s−1. The absolute J, W2, and ch2 magnitudes are in line with the coldest known Y dwarfs, despite the highly discrepant W1−W2 and ch1−ch2 colors. We explore possible reasons for the unique traits of this object and conclude that it is most likely an old, metal-poor brown dwarf and possibly the first Y subdwarf. Given that the object has an HST F110W magnitude of 24.7 mag, broadband spectroscopy and photometry from JWST are the best options for testing this hypothesis.

Radware Captcha Page

 

[Flyaway]

ESO captures best images yet of peculiar “dog-bone” asteroid

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), a team of astronomers have obtained the sharpest and most detailed images yet of the asteroid Kleopatra. The observations have allowed the team to constrain the 3D shape and mass of this peculiar asteroid, which resembles a dog bone, to a higher accuracy than ever before. Their research provides clues as to how this asteroid and the two moons that orbit it formed.

ESO captures best images yet of peculiar “dog-bone” asteroid

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), a team of astronomers have obtained the sharpest and most detailed images yet of the asteroid Kleopatra. The observations have allowed the team to constrain the 3D shape and mass of this peculiar asteroid, which...

www.eso.org

Accompanying video:

View: https://youtu.be/3TUjPyDeZec

 

[Flyaway]

A search of the full six years of the Dark Energy Survey for outer Solar System objects

We present the results of a search for outer Solar System objects in the full six years of data (Y6) from the Dark Energy Survey (DES). The DES covered a contiguous 5000 deg2 of the southern sky with ≈80,000 3 deg2 exposures in the grizY optical/IR filters between 2013 and 2019. This search yielded 815 trans-Neptunian objects (TNOs), one Centaur and one Oort cloud comet, with 461 objects reported for the first time in this paper. We present methodology that builds upon our previous search carried out on the first four years of data. Here, all DES images were reprocessed with an improved detection pipeline that leads to an average completeness gain of 0.47 mag per exposure, as well as an improved transient catalog production and optimized algorithms for linkage of detections into orbits. All objects were verified by visual inspection and by computing the sub-threshold significance, the total signal-to-noise ratio in the stack of images in which the object's presence is indicated by the orbit fit, but no detection was reported. This yields a highly pure catalog of TNOs complete to r≈23.8 mag and distances 29<d<2500 au. The Y6 TNOs have minimum (median) of 7 (12) distinct nights' detections and arcs of 1.1 (4.2) years, and will have grizY magnitudes available in a further publication. We present software for simulating our observational biases that enable comparisons of population models to our detections. Initial inferences demonstrating the statistical power of the DES catalog are: the data are inconsistent with the CFEPS-L7 model for the classical Kuiper Belt; the 16 ``extreme'' TNOs (a>150 au, q>30 au) are consistent with the null hypothesis of azimuthal isotropy; and non-resonant TNOs with q>38 au, a>50 au show a highly significant tendency to be sunward of the major mean motion resonances, whereas this tendency is not present for q<38 au.

[2109.03758] A search of the full six years of the Dark Energy Survey for outer Solar System objects

Source: https://www.sciencealert.com/over-4...-in-the-cold-dark-reaches-of-the-solar-system

 

[Flyaway]

Physicists at the University of Sussex have discovered that black holes exert a pressure on their environment, in a scientific first.

In 1974 Stephen Hawking made the seminal discovery that black holes emit thermal radiation. Previous to that, black holes were believed to be inert, the final stages of a dying heavy star.

The University of Sussex scientists have shown that they are in fact even more complex thermodynamic systems, with not only a temperature but also a pressure.

Physicists discover black holes exert a pressure in serendipitous scientific first

University of Sussex physicists find that black holes are complex thermodynamical systems, with not only a temperature but also a pressure

www.sussex.ac.uk

Quantum gravitational corrections to the entropy of a Schwarzschild black hole

ABSTRACT
We calculate quantum gravitational corrections to the entropy of black holes using the Wald entropy formula within an effective field theory approach to quantum gravity. The corrections to the entropy are calculated to second order in curvature and we calculate a subset of those at third order. We show that, at third order in curvature, interesting issues appear that had not been considered previously in the literature. The fact that the Schwarzschild metric receives corrections at this order in the curvature expansion has important implications for the entropy calculation. Indeed, the horizon radius and the temperature receive corrections. These corrections need to be carefully considered when calculating the Wald entropy.

Quantum gravitational corrections to the entropy of a Schwarzschild black hole

We calculate quantum gravitational corrections to the entropy of black holes using the Wald entropy formula within an effective field theory approach to quantum gravity. The corrections to the entropy are calculated to second order in curvature and we calculate a subset of those at third order...

journals.aps.org

 

[Rhinocrates]

Amateurs Spot New Impact Flash at Jupiter

An amateur astronomer has discovered a possible new impact flash in Jupiter's equatorial region. Observers may yet see the dark impact scar.

skyandtelescope.org

If Jupiter could talk: "Ow!"

 

[Justo Miranda]

We already have a Planet 9, Pluto, even if it is currently 'unpersoned', in a manner of speaking.

Nemesis, Planet X?

 

[Rhinocrates]

Something else to worry about. Miyake Events that dwarf the Carrington Event.

Solar 'Superflares' Rocked Earth Less Than 10,000 Years Ago--And Could Strike Again

Although our sun is considered a quiet star, it is now thought to have repeatedly pelted our planet with enormous eruptions in the not too distant past. Could another occur in the near future?

www.scientificamerican.com

 

[Richard N]

Meteor Crater - The World's Best Preserved Asteroid Impact Crater

View: https://www.youtube.com/watch?v=704POGQFDoQ

 

[Flyaway]

Water is essential for life on Earth and other planets, and scientists have found ample evidence of water in Mars’ early history. But Mars has no liquid water on its surface today. New research from Washington University in St. Louis suggests a fundamental reason: Mars may be just too small to hold onto large amounts of water.

Wang and his team measured the potassium isotope compositions of 20 previously confirmed Martian meteorites, selected to be representative of the bulk silicate composition of the red planet.

Using this approach, the researchers determined that Mars lost more potassium and other volatiles than Earth during its formation, but retained more of these volatiles than the moon and asteroid 4-Vesta, two much smaller and drier bodies than Earth and Mars.

The researchers found a well-defined correlation between body size and potassium isotopic composition.

"This study emphasizes that there is a very limited size range for planets to have just enough but not too much water to develop a habitable surface environment," said Klaus Mezger of the Center for Space and Habitability at the University of Bern, Switzerland, a co-author of the study. "These results will guide astronomers in their search for habitable exoplanets in other solar systems."

Wang now thinks that, for planets that are within habitable zones, planetary size probably should be more emphasized and routinely considered when thinking about whether an exoplanet could support life.

Mars habitability limited by its small size, isotope study suggests

Researchers measured the potassium isotope compositions of Martian meteorites in order to estimate the presence, distribution, and abundance of volatile elements and compounds, including water, on Mars, finding that Mars has lost more potassium than Earth but retained more potassium than the...

www.eurekalert.org

 

[Flyaway]

As the inhabitants of an ancient Middle Eastern city now called Tall el-Hammam went about their daily business one day about 3,600 years ago, they had no idea an unseen icy space rock was speeding toward them at about 38,000 mph (61,000 kph).

Flashing through the atmosphere, the rock exploded in a massive fireball about 2.5 miles (4 kilometers) above the ground. The blast was around 1,000 times more powerful than the Hiroshima atomic bomb. The shocked city dwellers who stared at it were blinded instantly. Air temperatures rapidly rose above 3,600 degrees Fahrenheit (2,000 degrees Celsius). Clothing and wood immediately burst into flames. Swords, spears, mudbricks and pottery began to melt. Almost immediately, the entire city was on fire.

Some seconds later, a massive shockwave smashed into the city. Moving at about 740 mph (1,200 kph), it was more powerful than the worst tornado ever recorded. The deadly winds ripped through the city, demolishing every building. They sheared off the top 40 feet (12 m) of the 4-story palace and blew the jumbled debris into the next valley. None of the 8,000 people or any animals within the city survived – their bodies were torn apart and their bones blasted into small fragments.

About a minute later, 14 miles (22 km) to the west of Tall el-Hammam, winds from the blast hit the biblical city of Jericho. Jericho’s walls came tumbling down and the city burned to the ground.

A giant space rock demolished an ancient Middle Eastern city and everyone in it – possibly inspiring the Biblical story of Sodom

New research suggests that fire from the sky in the form of a small asteroid annihilated a city near the Dead Sea 3,600 years ago.

theconversation.com

Related paper:

A Tunguska sized airburst destroyed Tall el-Hammam a Middle Bronze Age city in the Jordan Valley near the Dead Sea

We present evidence that in ~ 1650 BCE (~ 3600 years ago), a cosmic airburst destroyed Tall el-Hammam, a Middle-Bronze-Age city in the southern Jordan Valley northeast of the Dead Sea. The proposed airburst was larger than the 1908 explosion over Tunguska, Russia, where a ~ 50-m-wide bolide detonated with ~ 1000× more energy than the Hiroshima atomic bomb. A city-wide ~ 1.5-m-thick carbon-and-ash-rich destruction layer contains peak concentrations of shocked quartz (~ 5–10 GPa); melted pottery and mudbricks; diamond-like carbon; soot; Fe- and Si-rich spherules; CaCO3 spherules from melted plaster; and melted platinum, iridium, nickel, gold, silver, zircon, chromite, and quartz. Heating experiments indicate temperatures exceeded 2000 °C. Amid city-side devastation, the airburst demolished 12+ m of the 4-to-5-story palace complex and the massive 4-m-thick mudbrick rampart, while causing extreme disarticulation and skeletal fragmentation in nearby humans. An airburst-related influx of salt (~ 4 wt.%) produced hypersalinity, inhibited agriculture, and caused a ~ 300–600-year-long abandonment of ~ 120 regional settlements within a > 25-km radius. Tall el-Hammam may be the second oldest city/town destroyed by a cosmic airburst/impact, after Abu Hureyra, Syria, and possibly the earliest site with an oral tradition that was written down (Genesis). Tunguska-scale airbursts can devastate entire cities/regions and thus, pose a severe modern-day hazard.

A Tunguska sized airburst destroyed Tall el-Hammam a Middle Bronze Age city in the Jordan Valley near the Dead Sea - Scientific Reports

We present evidence that in ~ 1650 BCE (~ 3600 years ago), a cosmic airburst destroyed Tall el-Hammam, a Middle-Bronze-Age city in the southern Jordan Valley northeast of the Dead Sea. The proposed airburst was larger than the 1908 explosion over Tunguska, Russia, where a ~ 50-m-wide bolide...

www.nature.com

 

[Flyaway]

Regarding the above have a look at these threads. The above story may not be all that it seems.

https://twitter.com/x/status/1440473335687630865

View: https://mobile.twitter.com/MTB_Archaeology/status/1440473335687630865

https://twitter.com/x/status/1440112489123889155

View: https://twitter.com/MarkBoslough/status/1440112489123889155

https://twitter.com/x/status/1440377970497966089

View: https://mobile.twitter.com/MarkBoslough/status/1440377970497966089

 

[Flyaway]

More scepticism here about the paper.

https://twitter.com/x/status/1440404380386160646

View: https://mobile.twitter.com/ChrisStantis/status/1440404380386160646

 

[Flyaway]

Astronomers have found a huge cavity in space – and no definite explanation of where it came from.

The vast void is shaped like a sphere, stretches almost 500 light-years across and is found in space among the constellations Perseus and Taurus. The molecular clouds – regions where stars form – that are named after those constellations surround the cavity.

But despite that intriguing fact, scientists have not been able to pin down how exactly the cavity was formed.

Scientists find huge, mysterious ‘cavity’ in space

Astronomers have found a huge cavity in space – and no definite explanation of where it came from.

www.independent.co.uk

Unusual signals have led scientists to previously undiscovered galaxies – and there could be many, many more out there waiting to be found.

Scientists have long been looking to find more about the history of the early universe, by looking deep into space. Distant galaxies allow us to see how the universe was much closer to its beginning, effectively allowing astronomers to look back in time.

Strange signals reveal previously unknown galaxies

Unusual signals have led scientists to previously undiscovered galaxies – and there could be many, many more out there waiting to be found.

www.independent.co.uk

 

[Flyaway]

A ground-breaking detector that aims to use quartz to capture high frequency gravitational waves has been built by researchers at the ARC Centre of Excellence for Dark Matter Particle Physics (CDM) and The University of Western Australia.
In its first 153 days of operation, two events were detected that could, in principle, be high frequency gravitational waves, which have not been recorded by scientists before.
Such high frequency gravitational waves may have been created by a primordial black hole or a cloud of dark matter particles.

World-first detector reports rare events

A ground-breaking detector that aims to use quartz to capture high frequency gravitational waves has been built by researchers.

www.uwa.edu.au

 

[Flyaway]

THE EIGHT PLANETS of our Solar System aren’t the only ones we’ve ever had — they’re merely the survivors.

But that doesn’t mean the other planets were destroyed. Earth may have a long-lost sibling somewhere in interstellar space. At least one rocky planet, around the same mass as Mars, may have been booted out of the early Solar System.

The rogue planet scenario isn’t to be confused with Planet Nine, a much larger hypothetical planet that some planetary scientists suggest may be awaiting discovery even further out in trans-Neptunian space.

Another Planet 9? Earth's twin may be hiding in the outer Solar System

A recent review paper looks at our early Solar System and finds a now-missing sibling. It's not Planet Nine — instead it's Earth or Mars sized.

www.inverse.com

Transneptunian Space

Abstract

We provide a nonspecialist overview of the current state of understanding of the structure and origin of our Solar System's transneptunian region (often called the Kuiper Belt), highlighting perspectives on planetesimal formation, planet migration, and the contextual relationship with protoplanetary disks. We review the dynamical features of the transneptunian populations and their associated differences in physical properties. We describe aspects of our knowledge that have advanced in the past two decades and then move on to current issues of research interest (which thus still have unclear resolution).

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The current transneptunian population consists of both implanted and primordial objects.

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The primordial (aka cold) population is a largely unaltered remnant of the population that formed in situ.

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The reason for the primordial cold population's current outer edge is unexplained.

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The large semimajor-axis population now dynamically detached from Neptune is critical for understanding the Solar System's history.

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Observational constraints on the number and orbits of distant objects remain poor.

Transneptunian Space

We provide a nonspecialist overview of the current state of understanding of the structure and origin of our Solar System's transneptunian region (often called the Kuiper Belt), highlighting perspectives on planetesimal formation, planet migration, and the contextual relationship with...

www.annualreviews.org

 

[Archibald]

Posting a google search link because there is a lot of interesting stuff to read on the subject. The title only "lost siblings of the sun" sounds like sci-fi.

The bottom line: 5 billion years ago our Sun wasn't born alone but one among thousands young stars. They then scattered slowly across the Milky Way.

Astronomers have progressed to such a point, they know our Sun "signature" with such precision, they can look for its lost siblings. And damn it if they haven't found a couple of stars checking all the boxes.

"the lost siblings of the sun - Google Search

 

[Archibald]

Another fascinating reading, related to exoplanets.

List of nearest terrestrial exoplanet candidates - Wikipedia

en.wikipedia.org

List of nearest stars - Wikipedia

en.wikipedia.org

What is amazing is that, quite logically, most of these closest stars have long been picked by sci-fi authors for their stories.
- Centauri system
- Barnard star
- Epsilon eridani
- Procyon
- Tau Ceti
- Sirius
- Wolf 359
Familiar names !

And now, 2-3rd of them are known to have exoplanets, this time for real. So in a sense, reality has overtaken fiction.

 

[Flyaway]

A new study shows that they have been better able to describe this huge comet.

C/2014 UN271 (Bernardinelli-Bernstein): the nearly spherical cow of comets

C/2014 UN271 (Bernardinelli-Bernstein) is a comet incoming from the Oort cloud which is remarkable in having the brightest (and presumably largest) nucleus of any well-measured comet, and having been discovered at heliocentric distance rh≈29 au farther than any Oort-cloud member. We describe the properties that can be inferred from images recorded until the first reports of activity in June 2021. The orbit has i=95∘, with perihelion of 10.97 au to be reached in 2031, and previous aphelion at 40,400±260 au. Backwards integration of the orbit under a standard Galactic tidal model and known stellar encounters suggests this is a pristine new comet, with a perihelion of q≈18 au on its previous perihelion passage 3.5 Myr ago. The photometric data show an unresolved nucleus with absolute magnitude Hr=8.0, colors that are typical of comet nuclei or Damocloids, and no secular trend as it traversed the range 34--23 au. For r-band geometric albedo pr, this implies a diameter of 150(pr/0.04)−0.5 km. There is strong evidence of brightness fluctuations at ±0.2 mag level, but no rotation period can be discerned. A coma consistent with a ``stationary' 1/ρ surface-brightness distribution grew in scattering cross-section at an exponential rate from Afρ≈1 m to ≈150 m as the comet approached from 28 to 20 au. The activity is consistent with a simple model of sublimation of a surface species in radiative equilibrium with the Sun. The inferred enthalpy of sublimation matches those of CO2 and NH3. More-volatile species -- N2, CH4, and CO -- must be far less abundant on the sublimating surfaces.

[2109.09852] C/2014 UN271 (Bernardinelli-Bernstein): the nearly spherical cow of comets

 

[Grey Havoc]

747-sized asteroid skimmed by Earth, and scientists didn't see it coming

Dubbed 2021 SG, the asteroid flew close to the planet on September 16, but because it came from the direction of the Sun, scientists didn't see it coming.

www.jpost.com

 

[Flyaway]

The Colorado Ultraviolet Transit Experiment (aptly nicknamed CUTE) is a new, NASA-funded mission that aims to study the atmospheres of massive, superheated exoplanets – known as hot Jupiters – around distant stars. The miniaturized satellite, built by the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder, is set to launch this Monday, September 27th on an Atlas V rocket.

CUTE will spend its 7-month mission observing as many hot Jupiters as it can (10 at minimum), and measuring how quickly gas is escaping from them. Atmospheric escape is a process that happens to all planets, Earth included, but nothing like as quickly or on such large scales as on these hot Jupiters. Still, understanding how it works on these giants can help researchers understand how it works on rocky worlds too. If successful, the data CUTE gathers will be used to understand the processes of atmospheric escape on a wide range of different planet types.

A Tiny, Inexpensive Satellite Will be Studying the Atmospheres of hot Jupiters

The Colorado Ultraviolet Transit Experiment (aptly nicknamed CUTE) is a new, NASA-funded mission that aims to study the atmospheres of massive, superheated exoplanets – known as hot Jupiters – around distant stars. The miniaturized satellite, built by the Laboratory for Atmospheric and Space...

www.universetoday.com

 

[Archibald]

747-sized asteroid skimmed by Earth, and scientists didn't see it coming

Dubbed 2021 SG, the asteroid flew close to the planet on September 16, but because it came from the direction of the Sun, scientists didn't see it coming.

www.jpost.com

Peanuts - would have burned into the atmosphere or detonated above ground (it happened in the Channel recently - right between French Brittany and Great Britain)

NASA has now detected 99% of the asteroids that could devastate a city and larger, up to the planet.
Problem are indeed the ones small enough to be
- a) in large numbers and
- b) just big enough not to burn in the atmosphere and make limited damage on the ground
And b****rds like this one, coming straight out from the Sun.

 

[Flyaway]

The Faint Young Sun Paradox:

View: https://youtu.be/0gX4UZeOZ2M

 

[Flyaway]

Landsat 9 satellite will monitor coastal waters, glaciers & more:

View: https://youtu.be/y8WigIZfqgY

 

[Flyaway]

Landsat Earth observation satellites - A brief history:

View: https://youtu.be/M_263U_ovkQ