The Solar System - Word Search - PUZZLE #42 CHANDRA - August 2025

PUZZLE #42 - CHANDRA 

IN-CONTEXT WORD DEFINITIONS

Aurorae: Chandra observes X-ray emissions from aurorae, both on Earth and other planets like Jupiter. These are created when charged particles, often from the solar wind, are accelerated along magnetic field lines and collide with atoms in a planet's upper atmosphere, causing them to emit light, including X-rays. Research on Earth's X-ray aurora using Chandra data shows that these emissions are highly variable, appearing as intense arcs, multiple arcs, or diffuse glows. Chandra has observed dramatic auroral activity on Jupiter as well, revealing pulsating X-ray hotspots.

Exospheres: Chandra studies X-ray emissions from the exospheres of planets like Earth, Venus, and Mars. The exosphere is the outermost layer of a planetary atmosphere, where atoms and molecules are sparse and can escape into space. Chandra has determined that the primary mechanism for these X-ray emissions is charge exchange, where ions from the solar wind capture electrons from neutral atoms (mostly hydrogen) in the exosphere.

Fluorescence: Chandra utilizes X-ray fluorescence to study the composition of celestial objects. This occurs when high-energy X-rays from a source strike atoms, causing those atoms to emit their own characteristic X-rays at specific energies. For example, Chandra has measured the X-ray fluorescence spectra from the Moon's surface to determine its elemental chemistry, such as the abundance of Mg, Al, Si, Ca, and Fe. It's also used to investigate the material surrounding X-ray binaries.

Supernovae: Chandra plays a crucial role in studying supernovae, the powerful explosions marking the death of massive stars, and their remnants (SNRs). Chandra's high resolution and sensitivity allow astronomers to study the dynamics of the shock waves generated by supernovae, the acceleration of particles to near light speed, the distribution of heavy elements expelled by the explosion, and the mechanisms behind these explosions. Chandra data have helped analyze objects like Cassiopeia A and the Crab Nebula, revealing the elements forged inside the star and expelled into space.

Black Holes: Chandra has been instrumental in exploring the mysteries surrounding black holes, regions of spacetime where gravity is so strong that nothing, not even light, can escape. Chandra observations allow scientists to study the geometry of spacetime around black holes, the behavior of accreting material, the effects of black hole jets on their environment, and even the growth of supermassive black holes in the centers of galaxies according to Harvard University. Chandra is capable of detecting X-rays produced by hot gas and charged particles that penetrate thick clouds, providing a unique view of black holes, including Sagittarius A*, the supermassive black hole at the center of our Milky Way Galaxy.

Neutron Stars: Chandra observes neutron stars, the ultra-dense remnants of massive stars after supernova explosions. These objects, often only about 12 miles (19 km) in diameter, can generate powerful streams of high-energy particles extending for light-years. Chandra's observations have provided insights into the extreme conditions around neutron stars, including their magnetic fields, rotation, and internal structure. According to Harvard University, Chandra has helped to constrain the radius of neutron stars, providing information about the equation of state of matter at extreme densities.

Dark Matter: Chandra has provided crucial evidence for the existence and behavior of dark matter, the invisible substance that makes up the majority of the universe's mass. By studying the collisions of galaxy clusters, Chandra observations of the separation between hot gas (normal matter) and the overall mass distribution (dominated by dark matter) have strongly confirmed its existence. Chandra's observations also help to narrow down the possible properties of dark matter by observing how it interacts during collisions.

Quasars: Quasars are extremely luminous and distant active galactic nuclei powered by supermassive black holes. Chandra observations of quasars help study the properties of supermassive black holes and the evolution of galaxies at the earliest epochs of the universe. Chandra can penetrate the thick clouds of gas and dust surrounding these objects to reveal their X-ray emission, providing insights into their energetics and structure.

Nebulae: Chandra observes nebulae, which are clouds of gas and dust in space. These include supernova remnants (like the Crab Nebula and Cassiopeia A), which glow brightly in X-rays due to the high temperatures and energetic processes within them. Chandra also studies planetary nebulae, the shells of gas ejected by dying stars, observing the X-ray emission caused by shock waves when the stellar wind interacts with the ejected material.

Secret Word: Chandra observes galaxies to study a wide range of phenomena, including the X-ray emission from star formation, active galactic nuclei (AGN), and the distribution and properties of hot gas. Chandra has helped reveal the role of supermassive black holes in the evolution of massive galaxies, the dynamics of supernova remnants within galaxies, and the properties of galaxy clusters.