Lifeboat Foundation

Ocean currents spin off huge gyres, whose kinetic energy is transferred to ever-smaller turbulent structures until viscosity has erased velocity gradients and water molecules jiggle with thermal randomness. A similar cascade plays out in space when the solar wind slams into the magnetopause, the outer boundary of Earth’s magnetic field. The encounter launches large-scale magnetic, or Alfvén, waves whose energy ends up heating the plasma inside the magnetosphere. Here, however, the plasma is too thin for viscosity to mediate the cascade. Since 1971 researchers have progressively developed their understanding of how Alfvén waves in space plasmas generate heat. These studies later culminated in a specific hypothesis: Alfvén waves accelerate ion beams, which create small-scale acoustic waves, which generate heat. Now Xin An of UCLA and his collaborators have found direct evidence of that proposed mechanism [1]. What’s more, the mechanism is likely at work in the solar wind and other space plasmas.

Laboratory-scale experiments struggle to capture the dynamics of rotating plasmas, and real-world observations are even more scarce. The observations that An and his collaborators analyzed were made in 2015 by the four-spacecraft Magnetospheric Multiscale (MMS) mission. Launched that year, the MMS was designed to study magnetic reconnection, a process in which the topology of magnetic-field lines is violently transformed. The field rearrangements wrought by reconnection can be large, on the scale of the huge loops that sprout from the Sun’s photosphere. But the events that initiate reconnection take place in a much smaller region where neighboring field lines meet, the X-line. The four spacecraft of MMS can fly in a configuration in which all of them witness the large-scale topological transformation while one of them could happen to fly through the X-line—a place where no spacecraft had deliberately been sent before.

On September 8, 2015, the orbits of the MMS spacecraft took them through the magnetopause on the dusk side of Earth. They were far enough apart that together they could detect the passage of a large-scale Alfvén wave, while each of them could individually detect the motion of ions in the surrounding plasma. An and his collaborators later realized that these observations could be used to test the theory that ion beams and the acoustic waves that they generate mediate the conversion of Alfvén-wave energy to heat.

The examination of a sample brought from asteroid Ryugu in outer space turned exciting for scientists when they found it had life forms on it. However, soon the excitement died down when they found that the microbes on the sample had actually originated on Earth.

The sample was brought to Earth in 2020 after being gathered in 2019 during Japan’s Hayabusa2 mission.

Scientists treated the Ryugu samples with great care and kept them under strict contamination controls, limiting their chance of contamination.

An exploration of the mysteries of the cosmic microwave background radiation.

https://www.patreon.com/johnmichaelgodier.

Continue reading “The Mysteries of the Cosmic Microwave Background Radiation” »

In the vast reaches of space, invisible forces shape the behavior of charged particles in ways that are only now beginning to be fully understood.

A small team of astrophysicists at the University of California, Los Angeles, working with colleagues from the University of Texas at Dallas and the University of Colorado, Boulder, has found evidence that Alfvén waves in space plasmas speed up ion beams, resulting in the creation of small-scale acoustic waves that in turn generate heat in the magnetosphere.

In their study, published in the journal Physical Review Letters, the group used data from the four-spacecraft Magnetospheric Multiscale (MMS) mission that took place in 2015 to prove a theory about heat generation in the magnetosphere.

Continue reading “Astrophysicists find evidence that Alfvén waves lead to heat generation in the magnetosphere” »

An international team of astronomers has employed the James Webb Space Telescope (JWST) to observe a supermassive Galactic open cluster known as Westerlund 1. Results of the observational campaign, presented in a paper published Nov. 20 on the arXiv preprint server, yield important insights about the structure and properties of this cluster.

Open clusters (OCs), formed from the same giant molecular cloud, are groups of stars loosely gravitationally bound to each other. So far, more than 1,000 of them have been discovered in the Milky Way, and scientists are still looking for more, hoping to find a variety of these stellar groupings. Expanding the list of known galactic open clusters and studying them in detail could be crucial for improving our understanding of the formation and evolution of our galaxy.

It is assumed that most star formation takes place in massive clusters of stars, known as superstar clusters (SSCs). They are very massive young OCs usually containing a very large number of young, massive stars. The total mass of a typical SSC exceeds 10,000 solar masses.

Astronomers have been studying Earth’s ‘second moon’ since the cosmic object appeared in its orbit two months ago. Now the team has uncovered its mysterious origins.

Readily available thermoelectric generators operating under modest temperature differences can power CO₂ conversion, according to a proof-of-concept study by chemists at the University of British Columbia (UBC).

The findings open up the intriguing possibility that the temperature differentials encountered in an array of environments—from a typical geothermal installation on Earth to the cold, desolate surface of Mars—could power the conversion of CO₂ into a range of useful fuels and chemicals.

“The environment on Mars really got me interested in the long-term potential of this technology combination,” says Dr. Abhishek Soni, postdoctoral research fellow at UBC and first author of the paper published in Device.

Researchers studied tiny asteroid fragments from Ryugu, revealing that it originated in the outer solar system and evolved over billions of years.

Using Mössbauer spectroscopy, they discovered changes in the asteroid’s composition due to temperature shifts, offering new insights into the formation and migration of celestial bodies within our galaxy.

Exploring asteroid origins with advanced technology.

Trying to understand the makeup and evolution of the solar system’s Kuiper belt has kept researchers busy since it was hypothesized soon after the discovery of Pluto in 1930. In particular, binary pairs of objects there are useful as indicators since their existence today paints a picture of how energetic or violent the evolution of the solar system was in its early days four billion years ago.

Looking closely at the evolution of an ultrawide (in separation) binary object, researchers included more physics that reveals much about their architecture and unfolding. They found that these ultrawide binaries may not have been formed in the primordial solar system as has been thought. Their work has been published in Nature Astronomy.

“In the outer reaches of the solar system, there exists a population of binary systems so widely separated that it seemed worth looking into whether or not they could even survive 4 billion years without being [completely] separated somehow,” said Hunter M. Campbell of the University of Oklahoma in the US.