Why do comets and their meteoroid streams weave in and out of Earth's orbit and their orbits disperse over time? In a paper published online in the journal Icarus this week, two SETI Institute researchers show that this is not due to the random pull of the planets, but rather the kick they receive from a moving Sun.

"Contrary to popular conception, everything in the solar system does not orbit the Sun," said lead author and SETI Institute scientist Stuart Pilorz. "Rather, the Sun and planets all orbit their common center of mass, known to scientists as the solar system barycenter."

There is a large diversity in the chemical composition of astronomical objects such as planets, comets, circumstellar envelopes, or galactic gas clouds. One great challenge in astrochemistry is to understand in detail how this diversity arises from the cosmic backdrop of the cycling of matter between star birth and destruction, with molecules forming, reacting and coalescing in cold clouds of dust and ice in between these events.  Trivalent phosphorus, linked to anaerobic conditions on Earth, has also been found in the atmospheres of giant planets and in the distant interstellar medium. Phosphates are present in certain meteorites and on Saturn’s moon Enceladus. How did phosphorus make its way between these environments and ultimately became central to life on Earth? Studying here, in terrestrial laboratories, various properties of unfamiliar molecules that may wander interstellar space is an intriguing path. …a path being followed by scientists from the Institute of Physical Chemistry, Polish Academy of Sciences.

An international team led by the University of Geneva (UNIGE) has discovered the most distant spiral galaxy candidate known to date. This ultra-massive system existed just one billion years after the Big Bang and already shows a remarkably mature structure, with a central old bulge, a large star-forming disk, and well-defined spiral arms. The discovery was made using data from the James Webb Space Telescope (JWST) and offers important insights into how galaxies can form and evolve so rapidly in the early Universe. The study is published in Astronomy & Astrophysics.

SAN ANTONIO — April 15, 2025 —The Southwest Research Institute-led Lucy mission is preparing to survey the next target in its epic 4-billion-mile, 12-year, 11-asteroid tour. On April 20, 2025, NASA’s Lucy spacecraft will fly past the three-mile-wide main belt asteroid (52246) Donaldjohanson as a test run to the main event: visiting the never-before-explored Trojan asteroids in the Jupiter system.

A Southwest Research Institute-led study modeled the chemistry of TOI-270 d, an exoplanet between Earth and Neptune in size, finding evidence that it could be a giant rocky planet shrouded in a thick, hot atmosphere. TOI-270 d is only 73 light years from Earth and could serve as a “Rosetta Stone” for understanding an entire class of new planets.

First ever supercomputer simulations of Mars with a fully molten core could explain the Red Planet's unusual magnetic field. Billions of years ago, Mars had an active magnetic field. Mysteriously, its imprint is strongest in the southern hemisphere. Research led by the University of Texas Institute for Geophysics found that Mars could have produced a one-sided magnetic field with a fully molten core, rather than the traditional, Earth-like solid inner core setup.

Extreme cosmic events such as colliding black holes or the explosions of stars can cause ripples in spacetime, so-called gravitational waves. Their discovery opened a new window into the universe. To observe them, ultra-precise detectors are required. Designing them remains a major scientific challenge for humans. Researchers at the Max Planck Institute for the Science of Light (MPL) have been working on how an artificial intelligence system could explore an unimaginably vast space of possible designs to find entirely new solutions. The results were recently published in the journal ›Physical Review X‹.