Astronomy and Planetary Science Thread

[Rhinocrates]

An update on DART. Short version: it was even more effective than hoped. There are some interesting orbital dynamics, apparently as a result of all the boulders and dust blasted off Didymos' surface and then falling back again.

View: https://www.youtube.com/watch?v=MFvaA4H45zw

[2308.15488] New Post-DART Collision Period for the Didymos System: Evidence for Anomalous Orbital Decay

Hubble captures movie of DART asteroid impact debris

The NASA/ESA Hubble Space Telescope captured a series of photos of rapid changes to the asteroid Dimorphos when it was deliberately hit by a 545-kilogram spacecraft on 26 September 2022. The primary objective of the NASA mission, called DART (Double Asteroid Redirection Test), was to test our...

esahubble.org

Hubble sees boulders escaping from asteroid Dimorphos

Astronomers using the NASA/ESA/ Hubble Space Telescope’s extraordinary sensitivity have discovered a swarm of boulders that were possibly shaken off the asteroid Dimorphos when NASA deliberately slammed the half-tonne DART impactor spacecraft into Dimorphos at approximately 22 500 kilometres per...

esahubble.org

[2307.12506] The Dimorphos Boulder Swarm

Orbital period change of Dimorphos due to the DART kinetic impact - Nature

The 33 minute change in the orbital period of Dimorphos after the DART kinetic impact suggests that ejecta contributed a substantial amount of momentum to the asteroid compared with the DART spacecraft alone.

www.nature.com

 

[Flyaway]

This Exoplanet is Probably a Solid Ball of Metal

Gliese 367 b (or Tahay) is certainly an oddball. It’s an Ultrashort Period (USP) planet that orbits its star in only 7.7 hours. There are almost 200 other USP planets in our 5000+ catalogue of exoplanets, so Gliese 367 b isn’t unique in that regard. But it’s an outlier in another way: it’s also an ultra-dense planet—almost twice as dense as Earth.

This Exoplanet is Probably a Solid Ball of Metal

What can explain a small planet denser than Earth that orbits its star in 7days? Atmospheric Stripping? Collisions? Or was it born this way?

www.universetoday.com

 

[FighterJock]

That will be one hell of a strange planet Flyaway, to be made of solid metal. I wonder how many more planets like this one will be found?

 

[Archibald]

A heavy metal planet ?

 

[FighterJock]

Any ideas as to the type of metal the planet is made of Flyaway? Or is it too early to tell at this stage.

 

[TomS]

Any ideas as to the type of metal the planet is made of Flyaway? Or is it too early to tell at this stage.

It's in the article...

But it’s an outlier in another way: it’s also an ultra-dense planet—almost twice as dense as Earth.

That means it has to be almost pure iron.

 

[Archibald]

That means it has to be almost pure iron.

So - the Iron Maiden planet.

 

[publiusr]

If only we could swap it for Venus.

In the news

How close is too close to a kilonova?

Cataclysmic events happen in the universe all the time. Black hole mergers, supernovae, gamma-ray bursts, and a whole host of others. Most of them happen in distant galaxies, so they pose no threat to us. But there are a few that could affect life on Earth, and a couple could even pose an...

phys.org

Astrophysicists scan the galaxy for signs of life

The astrophysicists, from Trinity and the Breakthrough Listen team and Onsala Space Observatory in Sweden, are scanning the universe for "technosignatures" emanating from distant planets that would provide support for the existence of intelligent, alien life.

phys.org

Simulating space to explore the great mystery of interstellar chemistry

The universe is more than 13 billion years old and space is often depicted as a vast, empty vacuum. Other than planets and stars, there's nothing there, right? Actually, space is littered with complex, carbon-based molecules. However, the range of molecules and the chemistry involved in their...

phys.org

Astronomers carry out largest ever cosmological computer simulation

An international team of astronomers has carried out what is believed to be the largest ever cosmological computer simulation, tracking not only dark but also ordinary matter (such as planets, stars and galaxies), giving us a glimpse into how our universe may have evolved.

phys.org

The moon is 40 million years older than thought, lunar crystals study suggests

More than 4 billion years ago, when the solar system was still young and the Earth was still growing, a giant object the size of Mars crashed into the Earth. The biggest piece that broke off of the early Earth formed our moon. But precisely when this happened has remained a mystery.

phys.org

NASA X-ray telescopes reveal the 'bones' of a ghostly cosmic hand

In 1895, Wilhelm Röntgen discovered X-rays and used them to image the bones in his wife's hand, kicking off a revolutionary diagnostic tool for medicine. Now two of NASA's X-ray space telescopes have combined their imaging powers to unveil the magnetic field "bones" of a remarkable hand-shaped...

phys.org

The Crab Nebula seen in new light by NASA's Webb

Exquisite, never-before-seen details help unravel the supernova remnant's puzzling history.

phys.org

IXPE telescope untangles theories surrounding historic supernova remnant

NASA's IXPE (Imaging X-ray Polarimetry Explorer) telescope has captured the first polarized X-ray imagery of the supernova remnant SN 1006. The new results expand scientists' understanding of the relationship between magnetic fields and the flow of high-energy particles from exploding stars.

phys.org

Wearable devices may prevent astronauts getting 'lost' in space

The sky is no longer the limit—but taking flight is dangerous. In leaving the Earth's surface, we lose many of the cues we need to orient ourselves, and that spatial disorientation can be deadly. Astronauts normally need intensive training to protect against it. But scientists have now found...

phys.org

New patterns in Mars clouds revealed by volunteers

The first journal article about clouds identified by participants of the Cloudspotting on Mars project has been accepted for publication and is now available online. The article, "The Cloudspotting on Mars citizen science project: Seasonal and spatial cloud distributions observed by the Mars...

phys.org

Tracking near-Earth cosmic explosions

When massive stars or other stellar objects explode in the Earth's cosmic neighborhood, ejected debris can also reach our solar system. Traces of such events are found on Earth or the moon and can be detected using accelerator mass spectrometry, or AMS for short.

phys.org

Giant planets cast a deadly pall: How they can prevent life in other solar systems

Giant gas planets can be agents of chaos, ensuring nothing lives on their Earth-like neighbors around other stars. New studies show, in some planetary systems, the giants tend to kick smaller planets out of orbit and wreak havoc on their climates.

phys.org

Most Martian meteorites are curiously young in age

Earth is occasionally hit by little pieces of Mars. These bits of Martian rock are incredibly rare, but can tell us a lot about the geological history of the red planet. One of the biggest issues for scientists studying these meteorites, however, has been a difficulty in dating them. Different...

phys.org

In US capital, selfies with asteroid hinting at Earth's origins

In a hushed room of a museum in Washington, cameras and cell phones focus on a tiny piece of rock, no larger than a piece of gravel.

phys.org

NASA's Lucy spacecraft swoops past first of 10 asteroids on long journey to Jupiter

NASA's Lucy spacecraft on Wednesday encountered the first of 10 asteroids on its long journey to Jupiter.

phys.org

Asteroid dust caused 15-year winter that killed dinosaurs: Study

Around 66 million years ago, an asteroid bigger than Mount Everest smashed into Earth, killing off three quarters of all life on the planet—including the dinosaurs.

phys.org

 

[FighterJock]

There is nothing wrong with Venus publiusr. Venus is interesting in it's own unique way, such as having a runaway greenhouse effect and having active volcanoes.

 

[Flyaway]

It’s probably a bit like Psyche in our solar system a planetary core.

 

[Rhinocrates]

'Planetary science' as in our planet.

Nearly all mammals will go extinct in 250 million years as Earth warms

If humans still exist millions of years from now, they will face inhospitably warm conditions on a supercontinent centred at the equator. Most land mammals won't be able to survive

www.newscientist.com

Climate extremes likely to drive land mammal extinction during next supercontinent assembly - Nature Geoscience

The Earth may become inhospitable to land mammals in about 250 Myr owing to climate warming and drying associated with the assembly of the next supercontinent, Pangaea-Ultima, according to combined tectonic, climate and mammal habitability modelling.

doi.org

A couple of decades ago a series, The Future is Wild, presented such a scenario.

The Future Is Wild - Wikipedia

en.wikipedia.org

 

[robunos]

Interesting. Of course, it all depends on how the present continents arrange themselves into the next supercontinent. I've seen several configurations postulated, including one centered over the North pole . . .

Four scenarios for the next supercontinent

The arc of geological history is long, but it bends towards supercontinents – so, what will the next one look like?

bigthink.com

What planet Earth might look like when the next supercontinent forms – four scenarios | News and Events | Bangor University

www.bangor.ac.uk

cheers,
Robin.

 

[Flyaway]

Precessing jet nozzle connecting to a spinning black hole in M87

Abstract
The nearby radio galaxy M87 offers a unique opportunity to explore the connections between the central supermassive black hole and relativistic jets. Previous studies of the inner region of M87 revealed a wide opening angle for the jet originating near the black hole1,2,3,4. The Event Horizon Telescope resolved the central radio source and found an asymmetric ring structure consistent with expectations from general relativity5. With a baseline of 17 years of observations, there was a shift in the jet’s transverse position, possibly arising from an 8- to 10-year quasi-periodicity3. However, the origin of this sideways shift remains unclear. Here we report an analysis of radio observations over 22 years that suggests a period of about 11 years for the variation in the position angle of the jet. We infer that we are seeing a spinning black hole that induces the Lense–Thirring precession of a misaligned accretion disk. Similar jet precession may commonly occur in other active galactic nuclei but has been challenging to detect owing to the small magnitude and long period of the variation.

Precessing jet nozzle connecting to a spinning black hole in M87 - Nature

This study analyses radio observations of the jet in galaxy M87, from which the existence of a spinning black hole that induces Lense–Thirring precession of a misaligned accretion disk is inferred.

www.nature.com

 

[Flyaway]

Astronomers have used the observations by the Gaia satellite from the European Space Agency (ESA) to work out exactly how much mass the Milky Way has. And it turns out it is less than previous estimates, placing the total at 206 billion times the mass of our Sun.

Milky Way Weighs Less Than We Thought – And It's Missing Dark Matter

The most detailed map of our galaxy reveals that it moves as though there’s less stuff around.

www.iflscience.com

Related paper:

Detection of the Keplerian decline in the Milky Way rotation curve | Astronomy & Astrophysics (A&A)

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics

www.aanda.org

 

[Flyaway]

Yes they have jumped the gun on this as the preprint is out tomorrow so I’ve deleted the post.

 

[FighterJock]

Strange that the Milky Way is missing Dark Matter and weighs less than previously thought? What is going on with our home Galaxy all the stuff that I had known when I was younger is now being overrulled.

 

[Flyaway]

There could be a second Kuiper Belt just beyond the first one with a mysterious 10 AU gap between the two.

While using ground-based telescopes to hunt for fresh targets for NASA’s New Horizons spacecraft, now past Pluto on a course out of the Solar System, Fraser and his colleagues have made a tantalizing, though preliminary, discovery: about a dozen objects that lie beyond 60 AU—nearly as far from Pluto as Pluto is from the Sun. The finding, if real, could suggest that the Kuiper belt either extends much farther than once thought or—given the seeming 10-AU gap between these bodies and the known Kuiper belt—that a “second” belt exists.

https://www.science.org/content/article/puzzling-objects-found-far-beyond-neptune-hint-second-kuiper-belt

 

[Rhinocrates]

Interesting! This pricked up my ears, eyes, whatever:

Just as intriguing as the new objects is the apparent gap between 50 and 60 AU, says Mihály Horányi, a space physicist at the University of Colorado Boulder who oversees New Horizons’s dust counter. “One way or another, something is responsible for maintaining that gap.” In other solar systems, planets orbiting within a dusty disk carve gaps by hoovering up material. But no large planet has been seen in the gap. The gap could also be a relic from the Solar System’s infancy, caused by waves of pressure in the disk.

 

[publiusr]

Strange that the Milky Way is missing Dark Matter and weighs less than previously thought? What is going on?

Tapewormholes...the latest fad to fit into those lightcone corsets...now they have downsized the universe as well it seems.

I think MOND is helping them look for Planet 9 or whatever...a tweak like Mercury needed.

Now I wonder about Gliese 710.

Could that be a smaller, brighter object that is closer in?

 

[Flyaway]

No planet nine just MOND.

A pair of theoretical physicists are reporting that the same observations inspiring the hunt for a ninth planet might instead be evidence within the solar system of a modified law of gravity originally developed to understand the rotation of galaxies.

Plot thickens in hunt for ninth planet

<p>A pair of theoretical physicists are reporting that the same observations inspiring the hunt for a ninth planet might instead be evidence within the solar system of a modified law of gravity originally developed to understand the rotation of galaxies.</p>

www.eurekalert.org

 

[Flyaway]

An international team of scientists have discovered a huge spike in radiocarbon levels 14,300 years ago by analyzing ancient tree-rings. The radiocarbon spike was caused by a massive solar storm, the biggest ever identified.

…

Nine such extreme solar storms—known as Miyake Events—have now been identified as having occurred over the last 15,000 years studying tree-rings and ice layers records. The most recent confirmed Miyake Events occurred 1,030 and 1,250 years ago. This newly-identified 14,300-year-old storm is, however, the largest that has ever been found—roughly twice the size of these two.

Tree-Rings Show Extremely Powerful Solar Storm Hit Earth 14,300 Years ago

An international team of scientists have discovered a huge spike in radiocarbon levels 14,300 years ago by analyzing ancient tree-rings. This spike was caused by a massive solar storm hitting Earth, the biggest ever identified.

www.forbes.com

Related paper:

https://royalsocietypublishing.org/doi/10.1098/rsta.2022.0206

 

[FighterJock]

So what are the chances of another solar flare of that magnitude hittting the Earth again in our life times Flyaway?

 

[publiusr]

A failed Carrington event as it was called set off a lot of mines off the shores of Vietnam. The Niven story INCONSTANT MOON worries me a tad.

In other news, today phys.org had the story "SuperHeavy Elements/Ultradense asteroids" with z=118 and above perhaps in " CUDOS" like 33 Polyhymnia.

Maybe that could spark Space development...

 

[Flyaway]

Mysterious and rapid blasts of radiation that sweep over Earth could be the result of starquakes on "dead stars," or neutron stars. This connection could help scientists better understand earthquakes here on our planet.

Mysterious radiation bursts could be coming from 'starquakes' on neutron stars

If fast radio bursts that bombard Earth are linked to starquakes, they could help scientists better understand earthquakes on our planet.

www.space.com

 

[Rhinocrates]

Some asteroids have measured densities higher than those of any elements known to exist on Earth. This suggests that they are at least partly composed of unknown types of ‘ultradense’ matter that cannot be studied by conventional physics. Jan Rafelski and his team at the Department of Physics, The University of Arizona, Tucson, USA, suggest that this could consist of superheavy elements with atomic number (Z) higher than the limit of the current Periodic Table. They modelled the properties of such elements using the Thomas-Fermi model of atomic structure, concentrating particularly on a proposed ‘island of nuclear stability’ at and around Z=164 and extending their method further to include more exotic types of ultra-dense material. This work has now been published in EPJ Plus.

Beyond the Periodic Table: Superheavy Elements and Ultradense Asteroids | Springer — International Publisher

www.springer.com

 

[Flyaway]

The afterglow of a massive collision between two giant planets may have been detected for the first time. The wreckage of the collision could eventually cool and form an entirely new planet. If the observation is confirmed, it provides an amazing opportunity to watch the birth of a new world in real time and open a window into how planets form.

The afterglow of an explosive collision between giant planets may have been detected in a far-off star system

The discovery provides a way to study the birth of an entirely new planet in real time.

theconversation.com

 

[FighterJock]

Interesting Flyaway, I wonder how many more such detections we will discover?

 

[Flyaway]

Interesting Flyaway, I wonder how many more such detections we will discover?

First thing it reminded me of was that very old sci-fi film When Worlds Collide.

 

[Rhinocrates]

Some articles related to this discovery have brought up this:

Synestia - Wikipedia

en.wikipedia.org

What Are Synestias? — Synestias — An Interactive Primer

synestia.info

 

[publiusr]

First thing it reminded me of was that very old sci-fi film When Worlds Collide.

Gliese 710 is as close to that scenario as can be had…in a million years.

List of nearest stars and brown dwarfs - Wikipedia

en.m.wikipedia.org

Gliese 710 - Wikipedia

en.m.wikipedia.org

Each revision has its near-miss get closer…there are more GAIA data releases now—any further revisions?

 

[publiusr]

On space—a new view

A new view of all objects in the universe

The most comprehensive view of the history of the universe ever created has been produced by researchers at The Australian National University (ANU). The study also offers new ideas about how our universe may have started.

phys.org

Scientists and philosophers identify nature's missing evolutionary law

A paper published in the Proceedings of the National Academy of Sciences describes "a missing law of nature," recognizing for the first time an important norm within the natural world's workings.

phys.org

New map of space precisely measures nearly 400,000 nearby galaxies

Astronomers have created a detailed atlas of almost 400,000 galaxies in our cosmic neighborhood. The Siena Galaxy Atlas was compiled using data from NSF's NOIRLab telescopes, and is designed to be the preeminent digital galaxy atlas for large galaxies. It's a treasure trove of information for...

phys.org

 

[Flyaway]

Record concentrations of a helium isotope found inside 62-million-year-old Arctic rocks could be the most compelling evidence to date of a slow leak in our planet's core.

Building on the results of a previous analysis of ancient lava flows, a team of geochemists from Woods Hole Oceanographic Institution and the California Institute of Technology are now more certain than ever that helium trapped in the core as our planet was forming is making its way to the surface.

…

Basaltic lavas on Canada's Baffin Island contain some of the world's highest ratios of helium 3 (3He) to the slightly heavier isotope, helium 4 (4He). To geologists, such a mix indicates the gas's presence isn't contamination by the atmosphere, but rather a sign of deeper, more ancient origins.

Several years ago, Woods Hole Oceanographic Institution geochemist Forrest Horton uncovered helium isotope ratios of up to 50 times that of atmospheric levels in samples of olivine collected from Baffin's lava fields, making them high even for the mantle.

Our Planet's Core Seems to Be Leaking, And Scientists Think They Know Why

Record concentrations of a helium isotope found inside 62-million-year-old Arctic rocks could be the most compelling evidence to date of a slow leak in our planet's core.

www.sciencealert.com

Related paper:

Highest terrestrial 3He/4He credibly from the core - Nature

Olivines from Baffin Island lavas have the highest magmatic 3He/4He ratio measured so far in terrestrial igneous rocks, indicating that the helium in these lavas might derive from Earth’s core.

www.nature.com

 

[Flyaway]

The Moon is 40 million years older than previously thought new analysis of crystals brought back by Apollo 17 has shown.

The moon is 40 million years older than thought, lunar crystals study suggests

More than 4 billion years ago, when the solar system was still young and the Earth was still growing, a giant object the size of Mars crashed into the Earth. The biggest piece that broke off of the early Earth formed our moon. But precisely when this happened has remained a mystery.

phys.org

Related paper:

4.46 Ga zircons anchor chronology of lunar magma ocean | Geochemical Perspectives Letters

www.geochemicalperspectivesletters.org

 

[FighterJock]

So we got the date wrong when the Moon was formed, I wonder does the planetesimal crash still stand as the best method of formation?

 

[Flyaway]

An international team of researchers led by Dutch Ph.D. candidate Mark Snelders (ASTRON and University of Amsterdam) has discovered radio pulses from the distant universe that last only millionths of a second. They found these microsecond bursts after a meticulous examination of archival data from a known millisecond source. It's unclear how the ultrafast bursts are created.

Astronomers comb telescope archive and find microsecond-duration burst

An international team of researchers led by Dutch Ph.D. candidate Mark Snelders (ASTRON and University of Amsterdam) has discovered radio pulses from the distant universe that last only millionths of a second. They found these microsecond bursts after a meticulous examination of archival data...

phys.org

Related paper:

[2307.02303] Microsecond-duration bursts from FRB 20121102A

 

[Flyaway]

So we got the date wrong when the Moon was formed, I wonder does the planetesimal crash still stand as the best method of formation?

It does still stand as the best theory of its formation.

 

[Michel Van]

Asteroid 33 Polyhymnia is very strange object

in 2012 they could estimated it mass of (6.20±0.74)×10+18 kg, (do interaction with other Asteroids)
and here start the problem
Polyhymnia diameter is 54.39±11.84 km
this mass and diameter implies an extremely high density of 75.28±9.71 g/cm3 !
or ten time higher as lead

now there several proposal to mystery:

1. there is error in mass calculation ?, repeated in 2020 with same mass estimation...
2. Polyhymnia is not a Asteroid, but what then ? here goes speculation wild: Alien Spaceship or Probe
3. is their mini black hole in center of Polyhymnia ?
4. Transuranium element ? studies show theoretical, there are stable elements beyond Uran (the island of stability) with density of 60-80 g/cm3

The only way to find out what wrong with Polyhymnia, is send a spaceprobe

Sources:
Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, vol. 73, pp. 98–118,

Kretlow, Mike. "Size, Mass and Density of Asteroids (SiMDA) – Summary for: (33) Polyhymnia".
Size, Mass and Density of Asteroids (SiMDA). 12 October 2023.

 

[Flyaway]

The first super-Earth astronomers ever discovered has given off strange signals for nearly two decades, and scientists may have finally figured out why.

…

In the new study, the authors hypothesize that the planet's proximity to its star is causing it to outgas, meaning that giant volcanoes and thermal vents open up, spewing hot carbon-rich elements into the atmosphere. But the planet can't hold on to that atmosphere for long due to the extreme heat, and this gas eventually gets blown away, leaving the planet bare until the outgassing begins again.

Unlike most planets, the atmosphere of 55 Cancri e is unstable. The outgassing process tries to bulk up the atmosphere, while the extreme radiation and solar wind from the star blow it away. But these two processes are not in balance, leading to the situation where sometimes the planet has an atmosphere, and other times it doesn't.

The researchers believe this imbalance in the planetary atmosphere can explain the strange transit signals. When the planet is in its atmosphere-less "bald" phase, no visible light comes from the planet's atmosphere, because there isn't one, but the planet's hot surface still emits infrared light. When the atmosphere puffs up, both the visible light and all the radiation coming from the surface show up in the transit signal.

James Webb Space Telescope could have explained the mysterious signals from 'hell planet' 40 light-years away

The hellish super-Earth '55 Cancri e' may be constantly losing and re-growing its atmosphere, a new study of the planet's strange transit signals suggests.

www.space.com

 

[FighterJock]

Good find Flyaway, it is very strange that 55 Cancri e is losing and re-growing it's atmosphere. A weird set of surcumstances if I say so myself.

 

[Rhinocrates]

Just in Time for Halloween, NASA’s Juno Mission Spots Eerie “Face” on Jupiter - NASA

On Sept. 7, 2023, during its 54th close flyby of Jupiter, NASA’s Juno mission captured this view of an area in the giant planet’s far northern regions called

www.nasa.gov