Jun 19, 2022 10:45 PM
(This post was last modified: Jun 20, 2022 07:44 PM by C C.)
Voracious Jupiter ate a bunch of baby planets, scientists say
https://futurism.com/the-byte/jupiter-ate-baby-planets
EXCERPTS: Jupiter may be our solar system's hungriest hippo — as evidenced by new data from NASA's Juno probe that found the remains of a ton of smaller planets lurking beneath's the gas giant's opaque exterior.
A new paper published this month in the journal Astronomy & Astrophysics highlights findings from an international consortium of astronomers whose close study of the Juno data found that the gaseous mixture that makes up Jupiter is full of "heavy metal" elements, indicating that it devoured numerous "planetesimals," or baby planets, in the distant past.
[...] Jupiter was not only "one of the first planets to form in our solar system," but also "the most influential planet in the formation of the solar system," Yamila Miguel, a Dutch astrophysicist who led the research, told Live Science... (MORE - missing details)
Behold the Magnetar, nature’s ultimate superweapon
https://arstechnica.com/science/2022/06/...perweapon/
EXCERPTS: If you think black holes are the scariest things in the Universe, I have something to share with you.
There are balls of dead matter no bigger than a city yet shining a hundred times brighter than the Sun that send out flares of X-rays visible across the galaxy. Their interiors are made of superfluid subatomic particles, and they have cores of exotic and unknown states of matter. Their lifetime is only a few thousand years.
And here's the best part: They have the strongest magnetic fields ever observed, so strong they can melt you—literally dissociate you down to the atomic level—from a thousand kilometers away. These are the magnetars, perhaps the most fearsome entities ever known.
[...] I’m not kidding when I say that magnetars have the strongest magnetic fields in the Universe. To illustrate, let’s start with something you’re familiar with, the Earth’s magnetic field, and work up from there.
Measured at the North Pole, the Earth has a magnetic field strength of around half a Gauss. At its strongest, our planet can roughly double that number. That's pretty impressive—it's the most powerful magnetic field among the rocky planets of the Solar System—and enough to nudge a compass needle around for handy navigation.
The kind of magnet you stick on your fridge is about 100—200 times stronger than that and can easily counteract the gravitational might of the entire planet.
Moving off the Earth, sunspots reach magnetic field strengths of around 4,000 Gauss, the strongest in the Solar System.
Humans are capable of making some seriously powerful magnets. The most powerful sustained electromagnets reach a few tens of thousands of Gauss. If you've ever had an MRI, you have personally experienced around 10,000 Gauss with no ill effects (if you remembered to take off your jewelry). It's difficult for us to make stronger sustained magnetic fields because they tend to destroy the devices we use to make them. That said, inside of focused explosions, we can make magnetic fields that reach 10 million Gauss for a few microseconds.
A typical magnetar has a surface magnetic field strength of 10^14 to 10^15 Gauss, with interior strengths 10 times stronger. That is not a typo. Magnetars have magnetic fields about a quadrillion times stronger than the Earth's and a billion times stronger than the best that humanity can achieve.
If you get within approximately 1,000 kilometers of a magnetar, you die. Instantly. Leaving aside the copious amount of X-ray radiation constantly pouring out of these objects (we'll get to that), the magnetic fields make life literally impossible. The problem is that atoms are made of positively charged protons and negatively charged electrons. In weak magnetic fields, this doesn't make a bit of difference. But in strong fields, the electrons and protons respond differently. Atoms lose their traditional shape, and the electron orbitals become elongated along the direction of the magnetic field lines.
If you somehow made it to the surface of a magnetar, your individual atoms would only be 1 percent as wide as they are long. With atoms turning into needles, atomic physics as we know it breaks down. As does all the bonds that atoms use to glue themselves together into complex molecules.
In other words, the static magnetic field of a magnetar is strong enough to simply... dissociate you. All the molecules that you're made of simply come apart into oddly shaped atoms.
These insanely strong magnetic fields also affect the vacuum of space-time and the quantum foam, the seething froth of particles that constantly appear and disappear at subatomic scales. Many of those particles are electrically charged, and at these field strengths, the particles gyrate around the magnetic field lines at nearly the speed of light. This produces something called a birefringence in the vacuum itself. Like ordinary cellophane, the birefringence can split light into separate directions, leading to weird optical illusions, distortions, and magnification—all from the simple presence of the magnetic field... (MORE - missing details)
Martian meteorite upsets planet formation theory
https://www.ucdavis.edu/curiosity/news/m...ion-theory
RELEASE: A new study of an old meteorite contradicts current thinking about how rocky planets like the Earth and Mars acquire volatile elements such as hydrogen, carbon, oxygen, nitrogen and noble gases as they form. The work is published June 16 in Science.
A basic assumption about planet formation is that planets first collect these volatiles from the nebula around a young star, said Sandrine Péron, a postdoctoral scholar working with Professor Sujoy Mukhopadhyay in the Department of Earth and Planetary Sciences, University of California, Davis.
Because the planet is a ball of molten rock at this point, these elements initially dissolve into the magma ocean and then degass back into the atmosphere. Later on, chondritic meteorites crashing into the young planet deliver more volatile materials.
So scientists expect that the volatile elements in the interior of the planet should reflect the composition of the solar nebula, or a mixture of solar and meteoritic volatiles, while the volatiles in the atmosphere would come mostly from meteorites. These two sources -- solar vs. chondritic -- can be distinguished by the ratios of isotopes of noble gases, in particular krypton.
Mars is of special interest because it formed relatively quickly -- solidifying in about 4 million years after the birth of the Solar System, while the Earth took 50 to 100 million years to form.
"We can reconstruct the history of volatile delivery in the first few million years of the Solar System," Péron said.
Meteorite from Mars' interior. Some meteorites that fall to Earth come from Mars. Most come from surface rocks that have been exposed to Mars' atmosphere. The Chassigny meteorite, which fell to Earth in north-eastern France in 1815, is rare and unusual because it is thought to represent the interior of the planet.
By making extremely careful measurements of minute quantities of krypton isotopes in samples of the meteorite using a new method set up at the UC Davis Noble Gas Laboratory, the researchers could deduce the origin of elements in the rock.
"Because of their low abundance, krypton isotopes are challenging to measure," Péron said.
Surprisingly, the krypton isotopes in the meteorite correspond to those from chondritic meteorites, not the solar nebula. That means that meteorites were delivering volatile elements to the forming planet much earlier than previously thought, and in the presence of the nebula, reversing conventional thinking.
"The Martian interior composition for krypton is nearly purely chondritic, but the atmosphere is solar," Péron said. "It's very distinct."
The results show that Mars' atmosphere cannot have formed purely by outgassing from the mantle, as that would have given it a chondritic composition. The planet must have acquired atmosphere from the solar nebula, after the magma ocean cooled, to prevent substantial mixing between interior chondritic gases and atmospheric solar gases.
The new results suggest that Mars' growth was completed before the solar nebula was dissipated by radiation from the Sun. But the irradiation should also have blown off the nebular atmosphere on Mars, suggesting that atmospheric krypton must have somehow been preserved, possibly trapped underground or in polar ice caps.
"However, that would require Mars to have been cold in the immediate aftermath of its accretion," Mukhopadhyay said. "While our study clearly points to the chondritic gases in the Martian interior, it also raises some interesting questions about the origin and composition of Mars' early atmosphere."
Péron and Mukhopadhyay hope their study will stimulate further work on the topic.
https://futurism.com/the-byte/jupiter-ate-baby-planets
EXCERPTS: Jupiter may be our solar system's hungriest hippo — as evidenced by new data from NASA's Juno probe that found the remains of a ton of smaller planets lurking beneath's the gas giant's opaque exterior.
A new paper published this month in the journal Astronomy & Astrophysics highlights findings from an international consortium of astronomers whose close study of the Juno data found that the gaseous mixture that makes up Jupiter is full of "heavy metal" elements, indicating that it devoured numerous "planetesimals," or baby planets, in the distant past.
[...] Jupiter was not only "one of the first planets to form in our solar system," but also "the most influential planet in the formation of the solar system," Yamila Miguel, a Dutch astrophysicist who led the research, told Live Science... (MORE - missing details)
Behold the Magnetar, nature’s ultimate superweapon
https://arstechnica.com/science/2022/06/...perweapon/
EXCERPTS: If you think black holes are the scariest things in the Universe, I have something to share with you.
There are balls of dead matter no bigger than a city yet shining a hundred times brighter than the Sun that send out flares of X-rays visible across the galaxy. Their interiors are made of superfluid subatomic particles, and they have cores of exotic and unknown states of matter. Their lifetime is only a few thousand years.
And here's the best part: They have the strongest magnetic fields ever observed, so strong they can melt you—literally dissociate you down to the atomic level—from a thousand kilometers away. These are the magnetars, perhaps the most fearsome entities ever known.
[...] I’m not kidding when I say that magnetars have the strongest magnetic fields in the Universe. To illustrate, let’s start with something you’re familiar with, the Earth’s magnetic field, and work up from there.
Measured at the North Pole, the Earth has a magnetic field strength of around half a Gauss. At its strongest, our planet can roughly double that number. That's pretty impressive—it's the most powerful magnetic field among the rocky planets of the Solar System—and enough to nudge a compass needle around for handy navigation.
The kind of magnet you stick on your fridge is about 100—200 times stronger than that and can easily counteract the gravitational might of the entire planet.
Moving off the Earth, sunspots reach magnetic field strengths of around 4,000 Gauss, the strongest in the Solar System.
Humans are capable of making some seriously powerful magnets. The most powerful sustained electromagnets reach a few tens of thousands of Gauss. If you've ever had an MRI, you have personally experienced around 10,000 Gauss with no ill effects (if you remembered to take off your jewelry). It's difficult for us to make stronger sustained magnetic fields because they tend to destroy the devices we use to make them. That said, inside of focused explosions, we can make magnetic fields that reach 10 million Gauss for a few microseconds.
A typical magnetar has a surface magnetic field strength of 10^14 to 10^15 Gauss, with interior strengths 10 times stronger. That is not a typo. Magnetars have magnetic fields about a quadrillion times stronger than the Earth's and a billion times stronger than the best that humanity can achieve.
If you get within approximately 1,000 kilometers of a magnetar, you die. Instantly. Leaving aside the copious amount of X-ray radiation constantly pouring out of these objects (we'll get to that), the magnetic fields make life literally impossible. The problem is that atoms are made of positively charged protons and negatively charged electrons. In weak magnetic fields, this doesn't make a bit of difference. But in strong fields, the electrons and protons respond differently. Atoms lose their traditional shape, and the electron orbitals become elongated along the direction of the magnetic field lines.
If you somehow made it to the surface of a magnetar, your individual atoms would only be 1 percent as wide as they are long. With atoms turning into needles, atomic physics as we know it breaks down. As does all the bonds that atoms use to glue themselves together into complex molecules.
In other words, the static magnetic field of a magnetar is strong enough to simply... dissociate you. All the molecules that you're made of simply come apart into oddly shaped atoms.
These insanely strong magnetic fields also affect the vacuum of space-time and the quantum foam, the seething froth of particles that constantly appear and disappear at subatomic scales. Many of those particles are electrically charged, and at these field strengths, the particles gyrate around the magnetic field lines at nearly the speed of light. This produces something called a birefringence in the vacuum itself. Like ordinary cellophane, the birefringence can split light into separate directions, leading to weird optical illusions, distortions, and magnification—all from the simple presence of the magnetic field... (MORE - missing details)
Martian meteorite upsets planet formation theory
https://www.ucdavis.edu/curiosity/news/m...ion-theory
RELEASE: A new study of an old meteorite contradicts current thinking about how rocky planets like the Earth and Mars acquire volatile elements such as hydrogen, carbon, oxygen, nitrogen and noble gases as they form. The work is published June 16 in Science.
A basic assumption about planet formation is that planets first collect these volatiles from the nebula around a young star, said Sandrine Péron, a postdoctoral scholar working with Professor Sujoy Mukhopadhyay in the Department of Earth and Planetary Sciences, University of California, Davis.
Because the planet is a ball of molten rock at this point, these elements initially dissolve into the magma ocean and then degass back into the atmosphere. Later on, chondritic meteorites crashing into the young planet deliver more volatile materials.
So scientists expect that the volatile elements in the interior of the planet should reflect the composition of the solar nebula, or a mixture of solar and meteoritic volatiles, while the volatiles in the atmosphere would come mostly from meteorites. These two sources -- solar vs. chondritic -- can be distinguished by the ratios of isotopes of noble gases, in particular krypton.
Mars is of special interest because it formed relatively quickly -- solidifying in about 4 million years after the birth of the Solar System, while the Earth took 50 to 100 million years to form.
"We can reconstruct the history of volatile delivery in the first few million years of the Solar System," Péron said.
Meteorite from Mars' interior. Some meteorites that fall to Earth come from Mars. Most come from surface rocks that have been exposed to Mars' atmosphere. The Chassigny meteorite, which fell to Earth in north-eastern France in 1815, is rare and unusual because it is thought to represent the interior of the planet.
By making extremely careful measurements of minute quantities of krypton isotopes in samples of the meteorite using a new method set up at the UC Davis Noble Gas Laboratory, the researchers could deduce the origin of elements in the rock.
"Because of their low abundance, krypton isotopes are challenging to measure," Péron said.
Surprisingly, the krypton isotopes in the meteorite correspond to those from chondritic meteorites, not the solar nebula. That means that meteorites were delivering volatile elements to the forming planet much earlier than previously thought, and in the presence of the nebula, reversing conventional thinking.
"The Martian interior composition for krypton is nearly purely chondritic, but the atmosphere is solar," Péron said. "It's very distinct."
The results show that Mars' atmosphere cannot have formed purely by outgassing from the mantle, as that would have given it a chondritic composition. The planet must have acquired atmosphere from the solar nebula, after the magma ocean cooled, to prevent substantial mixing between interior chondritic gases and atmospheric solar gases.
The new results suggest that Mars' growth was completed before the solar nebula was dissipated by radiation from the Sun. But the irradiation should also have blown off the nebular atmosphere on Mars, suggesting that atmospheric krypton must have somehow been preserved, possibly trapped underground or in polar ice caps.
"However, that would require Mars to have been cold in the immediate aftermath of its accretion," Mukhopadhyay said. "While our study clearly points to the chondritic gases in the Martian interior, it also raises some interesting questions about the origin and composition of Mars' early atmosphere."
Péron and Mukhopadhyay hope their study will stimulate further work on the topic.
