Ancient Australian rocks suggest Earth’s continents formed later than expected and share a common origin with the Moon.
Category: space – Page 2
NASA’s Chandra rings in the new year with the Champagne Cluster
Celebrate the New Year with the “Champagne Cluster,” a galaxy cluster seen in this new image from NASA’s Chandra X-ray Observatory and optical telescopes.
Astronomers discovered this galaxy cluster on Dec. 31, 2020. The date, combined with the bubble-like appearance of the galaxies and the superheated gas seen with Chandra observations (represented in purple), inspired the scientists to nickname the galaxy cluster the Champagne Cluster, a much easier-to-remember name than its official designation of RM J130558.9+263048.4.
The new composite image shows that the Champagne Cluster is actually two galaxy clusters in the process of merging to form an even larger cluster.
The origami wheel that could explore lunar caves
Beneath the moon’s cratered surface lie networks of lava tubes and deep pits, natural caves that could shelter future lunar bases from cosmic radiation and wild temperature swings. These underground structures represent some of the most scientifically valuable areas in the solar system, but they come with the very real challenge of simply getting there.
The entrances to these caves feature steep, rugged terrain with rocks and loose regolith. Small rovers, preferred for lunar exploration because you can deploy many of them to reduce mission risk, face an inherent limitation. Their compact wheels simply can’t climb over obstacles much larger than the wheel diameter itself. Send a swarm of small rovers and even if some fail, others continue the mission. Send one large rover and a single failure ends everything.
Variable diameter wheels are a new thing in lunar exploration and could solve this, expanding when needed to overcome obstacles, then contracting for efficient transport. But building such a wheel for the moon has proven nearly impossible. The lunar environment is uniquely hostile to mechanical systems. Fine, abrasive dust infiltrates everything, and in the airless vacuum, exposed metal surfaces stick together through a process called cold welding. Traditional hinges and joints don’t last long under these conditions.
The Star of Bethlehem might have actually been a comet described in an ancient Chinese text
Many researchers have spent decades attempting to decode biblical descriptions and link them to verifiable historical events. One such description is that of the Star of Bethlehem—a bright astronomical body that was said to lead the Magi to Jesus shortly after his birth.
Although many attempts have been made to link the Star of Bethlehem to astronomical bodies, the unique motion of the “star” did not quite fit any known object. However, a new research study, published in Journal of the British Astronomical Association, describes a likely candidate for the bright object seen above Bethlehem over 2000 years ago—a comet described in an ancient Chinese text.
Veritas explores the nature of a mysterious gamma-ray emitter
Astronomers have employed the Very Energetic Radiation Imaging Telescope Array System (VERITAS) to observe a mysterious gamma-ray emitting source designated HESS J1857+026. Results of the observational campaign, published December 19 on the pre-print server arXiv, shed more light on the nature of this source.
Bose-Einstein Condensate; When Atoms Act As One
Bose–Einstein Condensate (BEC) explained: Cool a dilute gas of atoms to billionths of a degree above absolute zero and they merge into one coherent matter wave—a Bose–Einstein condensate. This video covers laser cooling, magnetic/optical traps, evaporative cooling, the onset of quantum degeneracy, and why a BEC behaves like a superfluid. See signatures: interference fringes, quantized vortices, long coherence length, and frictionless flow. Applications include atom interferometers (precision gravity and rotation sensing), quantum simulation of complex materials, and space-based experiments (ISS Cold Atom Lab). We also touch on first BECs (1995, rubidium/sodium), critical temperature, and why bosons condense while fermions do not.
Behold the Manifold, the Concept that Changed How Mathematicians View Space
The world is full of such shapes—ones that look flat to an ant living on them, even though they might have a more complicated global structure. Mathematicians call these shapes manifolds. Introduced by Bernhard Riemann in the mid-19th century, manifolds transformed how mathematicians think about space. It was no longer just a physical setting for other mathematical objects, but rather an abstract, well-defined object worth studying in its own right.
This new perspective allowed mathematicians to rigorously explore higher-dimensional spaces—leading to the birth of modern topology, a field dedicated to the study of mathematical spaces like manifolds. Manifolds have also come to occupy a central role in fields such as geometry, dynamical systems, data analysis, and physics.
To unify relativity and quantum mechanics we must abandon materialism
Physicists have so far failed to unify general relativity and quantum mechanics. As attempts to unite them into a quantum theory of gravity mount up, philosopher of physics Dean Rickles argues that the assumption of materialism is the problem. We need to look beyond the physical—beyond space, time and matter—to something primordial out of which minds can construct physical reality, and which explains both general relativity and quantum mechanics. Pioneers like John Wheeler and David Bohm have already begun to chart what such a realm of “pre-physics” might look like—it’s high time physics took their ideas more seriously.
A pair of recent physics Nobel prizes (2020 and 2022) were awarded for basic research in general relativity (Einstein’s theory of gravitation that explains gravity as the curvature of spacetime by matter and energy) and quantum mechanics (our best bet for a theory of matter and energy). The experimental successes of these theories keep piling up. There is clearly much truth in them. They both aim to describe the same world: this world. They should surely overlap, since the matter and energy described by quantum mechanics should curve spacetime as well as good old-fashioned non-quantum mechanical matter and energy. Why then can we not construct a theory in which they both appear? Why is it so difficult to build what would be a Quantum Theory of Gravity?
