All posts tagged: Space News

ESA’s Solar Orbiter reveals how the Sun’s corona transforms into solar wind

ESA’s Solar Orbiter reveals how the Sun’s corona transforms into solar wind

Published by Jenni Sidey

Solar Orbiter crossed the heliospheric current sheet only about 0.3 astronomical units from the Sun, giving researchers an unusually fresh look at solar wind before its original signatures were heavily altered in transit. The spacecraft found that the iron-to-oxygen ratio fell sharply at the magnetic sector boundary, showing that the current sheet carries a distinctive chemical signature as well as a reversal in magnetic polarity. The observations came from a single crossing, so they do not establish how the current sheet forms, but they give future models specific measurements of composition, heating and magnetic structure that they must explain. An enormous magnetic boundary stretching outward from the Sun is turning out to be more complicated than a simple dividing line. Measurements from the European Space Agency’s Solar Orbiter show that the heliospheric current sheet, or HCS, contains organized changes in the composition and temperature of its particles. Those chemical fingerprints may help scientists trace solar wind back toward the processes that released it from the Sun. The results appear in The Astrophysical Journal in the …

JWST finds mysterious red objects pairing up in the early universe

JWST finds mysterious red objects pairing up in the early universe

Published by Jenni Sidey

JWST images have revealed four candidate pairs of “little red dots,” compact early-universe objects increasingly associated with rapidly growing black holes. Two pairs have spectroscopic evidence that both components lie at the same redshift, while statistical tests make simple chance alignment an unlikely explanation for all four systems. If these objects contain growing black holes that eventually merge, such systems could help explain early supermassive black hole growth and become targets for future gravitational-wave observatories. Astronomers analyzing high-resolution infrared observations have identified four candidate pairs of “little red dots,” or LRDs, separated by only a few thousand to several tens of thousands of light-years. The compact objects existed when the universe was only about a billion years old. The findings raise the possibility that some rapidly growing early black holes were being brought together by galaxy interactions, creating systems that could eventually end in black hole mergers. Schematic figure of the pixel-by-pixel color selection method. We construct and color maps using PSF-matched F277W and F444W images. (CREDIT: Takumi Tanaka et al, Publications of the Astronomical …

The universe still has plenty of hydrogen, so why is it making fewer stars?

The universe still has plenty of hydrogen, so why is it making fewer stars?

Published by Jenni Sidey

Cosmic star formation has fallen by a factor of about 2.46 over the past 4.5 billion years, but the density of neutral atomic hydrogen has declined far less. FAST and DESI observations of roughly 2.5 million galaxies show that galaxies have retained much of their atomic gas even as the universe became less efficient at producing stars. The findings shift attention from simply running out of hydrogen toward the processes that move gas into the dense molecular form that directly feeds star formation. The universe is not producing stars at anything close to the rate it once did. Over the past 4.5 billion years, the cosmic star formation rate has fallen by more than half as galaxies have gradually become quieter. A simple explanation would be that galaxies are running out of fuel. New measurements suggest the story is considerably more complicated. An international team, including members from the Chinese Academy of Sciences (CAS), using China’s Five-hundred-meter Aperture Spherical radio Telescope, or FAST, and the Dark Energy Spectroscopic Instrument has found that the universe’s supply …

Mars’s mantle may be hundreds of degrees hotter beneath one hemisphere

Mars’s mantle may be hundreds of degrees hotter beneath one hemisphere

Published by Jenni Sidey

Mars’s mantle beneath the southern highlands appears to be about 200 to 400 degrees Celsius warmer than the mantle beneath the northern lowlands. Nearly two decades of spacecraft tracking data revealed gravity changes that suggest the planet’s deep interior is far less uniform than scientists often assume. The thermal divide could help explain differences in Mars’s crust, ancient magnetism and seismic behavior, but its origin remains uncertain. Mars has long looked like a planet divided in two. Its southern hemisphere rises into rugged, heavily cratered highlands, while broad, relatively flat lowlands dominate the north. That contrast may extend much farther beneath the surface than scientists realized. An analysis of subtle changes in Mars’s gravitational field indicates that the mantle beneath the southern highlands is roughly 200 to 400 degrees Celsius warmer than the mantle beneath the northern lowlands. The finding suggests one of the planet’s defining surface differences may have roots deep inside Mars that have survived for billions of years. The research, published in Nature was led by Caltech alumnus Alexander Berne, now a …

The Moon’s far side could open a window into the universe before the first stars were born

The Moon’s far side could open a window into the universe before the first stars were born

Published by Jenni Sidey

The Moon’s far side could give astronomers access to radio signals from the cosmic “dark ages,” a period before the first stars and galaxies formed. The idea has moved beyond theory. NASA’s first lunar radio telescope has already operated on the Moon, while LuSEE-Night is being prepared for a far-side landing and new missions such as CosmoCube are taking shape. Astronomers are also racing against a new problem: growing lunar activity could contaminate one of the quietest radio environments available anywhere near Earth. The far side of the Moon is a battered landscape of mountains, basins and overlapping craters, strikingly different from the broad dark plains familiar to anyone looking up from Earth. But its most valuable feature for astronomers may be something that cannot be seen at all. The Moon itself blocks much of the radio noise pouring outward from Earth. With virtually no atmosphere to distort very low-frequency signals, the far side offers an observing environment unavailable to telescopes on our planet. NASA now describes it as the only known place in the …

Scientists reproduce a long-predicted flow state from deep inside planets

Scientists reproduce a long-predicted flow state from deep inside planets

Published by Jenni Sidey

A liquid-gallium experiment has reproduced a turbulent convection regime long predicted to occur inside rapidly rotating planets and stars. Heat transport, flow velocity and temperature fluctuations all matched theoretical predictions, giving researchers three independent tests of the same physical model. The results strengthen the case that small laboratory experiments can help scientists model inaccessible processes deep inside planets and stars. The interiors of stars and planets remain largely beyond direct observation. Instead, scientists build experiments that reproduce pieces of the physics expected to operate under conditions that cannot be reached or observed directly. A rotating tank filled with liquid gallium has now provided an important test of one such idea. An international team led by the University of California, Los Angeles has experimentally reproduced a turbulent flow state predicted to occur in the interiors of rapidly rotating celestial bodies. The state, known as rotating diffusivity-free turbulent convection, had been predicted theoretically for decades but had resisted clear confirmation in a conventional laboratory experiment. The results, published in Physical Review Letters, showed quantitative agreement among laboratory …

Powerful magnetic fields could be trapping giant stellar eruptions before they escape

Powerful magnetic fields could be trapping giant stellar eruptions before they escape

Published by Jenni Sidey

Powerful magnetic fields around active stars may trap huge coronal mass ejections before they can escape into space. Laboratory plasma experiments found that stronger magnetic fields caused CME-like flows to fragment, bend and eventually stop. The results could help explain why astronomers rarely detect stellar CMEs despite seeing powerful flares on stars far more active than the Sun. Some of the most active stars in the galaxy appear capable of producing enormous eruptions, yet astronomers rarely see those blasts escaping into space. Experiments recreating part of that process in a laboratory now offer a possible explanation. Strong stellar magnetic fields may act as a cage, destabilizing massive flows of plasma until they break apart and stop. An international team of astrophysicists and plasma physicists from the Leibniz Institute for Astrophysics Potsdam (AIP), Germany, École Polytechnique and the Technion-Israel Institute of Technology, combined stellar simulations, high-energy laser experiments and three-dimensional magnetohydrodynamic modeling to investigate why coronal mass ejections are so difficult to find beyond the Sun. The results provide experimental evidence that sufficiently strong magnetic fields …

NASA’s Roman Space Telescope launches to map billions of galaxies and hunt distant worlds

NASA’s Roman Space Telescope launches to map billions of galaxies and hunt distant worlds

Published by Jenni Sidey

NASA’s Nancy Grace Roman Space Telescope successfully launched aboard a SpaceX Falcon Heavy and is now beginning its journey toward a position about one million miles from Earth. Roman combines Hubble-like sharpness with a field of view at least 100 times larger, allowing it to survey enormous numbers of galaxies, stars and planets. The mission will investigate dark energy and dark matter, search for thousands of exoplanets and build huge public datasets that could reveal objects astronomers have never seen before. A space telescope built to see the universe on an enormous scale has left Earth. NASA’s Nancy Grace Roman Space Telescope lifted off at 7:26 a.m. EDT Sunday, Aug. 30, aboard a SpaceX Falcon Heavy rocket from Launch Complex 39A at Kennedy Space Center in Florida. Roman separated from the rocket’s second stage at 7:57 a.m. and began flying independently toward the second Sun-Earth Lagrange point, or L2, about one million miles from Earth. Mission controllers received telemetry from Roman shortly after launch, and NASA later confirmed that its solar panels and lower instrument …

Powerful new magnetic system could help spacecraft survive the brutal heat of reentry

Powerful new magnetic system could help spacecraft survive the brutal heat of reentry

Published by Jenni Sidey

Tokyo Metropolitan University researchers built a pulsed electromagnet system that can test magnetic aerobraking under shockwaves traveling about 7.7 kilometers per second. The system produced magnetic fields of 1.24 and 1.58 tesla, reaching roughly 1.7 and 2.1 times the strength of the permanent magnet used for comparison. Applying the magnetic field expanded the glowing shock layer by about 16%, supporting the idea that magnetic forces could someday help protect and slow spacecraft during atmospheric reentry. A spacecraft plunging into an atmosphere faces an environment violent enough to heat the gas around its surface to thousands of degrees. Engineers have traditionally dealt with that punishment by putting something tough, expendable or both between the vehicle and the heat. A different approach could eventually use magnetic fields to push some of that superheated gas away. Researchers at Tokyo Metropolitan University have developed an experimental system that produces unusually strong magnetic fields inside miniature spacecraft models while exposing them to shockwaves traveling at roughly 7.7 kilometers per second. The setup allows engineers to study magnetohydrodynamic aerobraking, or MHD …

Physics-trained AI reveals how Earth’s deep interior changed over time

Physics-trained AI reveals how Earth’s deep interior changed over time

Published by Jenni Sidey

Earth’s mantle moves only a few centimeters each year, but that slow motion helps drive plate tectonics, earthquakes and volcanic activity. A physics-guided AI model reconstructed hidden mantle flow in a controlled simulation using limited surface motion and present-day temperature clues. The work is an early test, not a real-Earth reconstruction, but it could help scientists study how the deep planet changed over time. Deep inside Earth, rock moves at the pace of growing fingernails. That slow circulation shapes plates, feeds volcanoes and influences earthquakes, yet much of its past remains hidden from direct view. The mantle, a rocky layer that accounts for more than 80 percent of Earth’s volume, circulates only a few centimeters per year. Over geological time, that movement helps drive plate tectonics and major surface activity. But scientists cannot simply watch the deep mantle move. They must rely on surface geology and geophysical imaging, including seismic observations, to infer what lies below. A new study by the University of Tsukuba tested whether artificial intelligence could help reconstruct that missing history. The …