The construction of a cosmic distance ladder begins with measuring the parallax of individual stars within the Milky Way and its satellites, such as Cepheids. Then we identify those same stars in nearby galaxies that also house other measurable distance...
In inflationary cosmology, the volume that space occupies is stretched to an inconceivably large volume in a tiny fraction of a second, and wherever inflation ends, a hot Big Bang (and a Universe like ours) ensues. This creates a virtual...
If you measure the expansion rate of the Universe using an early relic method, like the light from the CMB (top right), you get a value of around 67 km/s/Mpc. If you measure it by constructing a distance ladder (below...
This clip from NASA’s PUNCH satellite shows a strong coronal mass ejection emanating from the Sun’s limb (top) on June 3, 2025: the first non-halo CME observed since the spacecrafts were launched on March 11, 2025. (Credit: NASA/SwRI)Launched in March,...
At the centers of galaxies, orbiting stars experience close interactions with the central supermassive black holes at a galaxy’s core. Stars that pass too close, particularly in multi-star systems, are at risk of receiving hypervelocity kicks and being ejected from...
When the Universe undergoes a period of cosmic inflation, the fabric of space — which has a tremendously high energy density — expands at an exponential rate, creating new space (also full of large amounts of energy) with each moment...
Our Universe, as far back as we can trace it, has been expanding at a rate that is dependent on the sum total of all the forms of energy within it. There’s one equation, the first Friedmann equation, that details...
Uranus, with its ringed system, is shown alongside its five largest moons. From left-to-right are Ariel, Miranda, Umbriel, Oberon, and Titania. In terms of orbital distance, however, the order goes Miranda, Ariel, Umbriel, Titania, and then Oberon. (Credit: NASA, ESA,...
When high-energy cosmic particles strike the top of Earth’s atmosphere, they produce showers of “daughter” particles that will find their way down to Earth. On the surface, we’ve built several notable detector arrays, including the Pierre Auger Observatory and the...
The largest galaxies displayed here aren’t blurry because they’re overexposed or because of atmospheric interference, but rather because JWST is outstandingly exposing their diffuse, extended stellar halos. Behind the central and lower-right galaxies are more distant, gravitationally lensed background galaxies,...
