Is it groupthink? Or is there a deeper reason? In the early half of the 20th century, even after the discovery of the expanding Universe, physicists considered a wide variety of […]

We have to use the right definition for the specific question we’re asking. When it comes to the Universe, we frequently characterize objects by examining and reporting on their physical […]

And, at some point, did the Milky Way lose ours? There are some 400 billion objects flying through the Milky Way galaxy with enough mass that — if they were all made of […]

Science can teach us so much about our planet, but something more must compel us to take care of it. If you want to understand our planet, the best way to […]

While Mars is known as a frozen, red planet today, it has all the evidence we could ask for of a watery past, lasting for approximately the first 1.5 billion […]

We’ve almost got the entire story. James Webb will put the last piece into place. In all of science, there are really only two ways that something can be “known” to […]

Mass determines a star’s fate… except when it doesn’t. Supernova events are common, visually spectacular astronomical cataclysms. In 1987, a supernova just ~168,000 light-years away was observed in the Large Magellanic […]

And could Earth-based life provide the seeds for biology elsewhere? Today, on Earth, there’s an enormous variety and diversity of life on our planet. Every single surviving lifeform appears, in […]

Even 13.8 billion years after the Big Bang, we can reconstruct the first 3 minutes. About 100 years ago, we began to truly understand the nature of the Universe for the […]

Only 3% of physics graduates and 2% of astronomy graduates are Black. That’s got to change. In the late 1990s, about 5% of the approximately 4000 bachelor’s degrees in physics per […]

Only 17 years after its discovery have we learned we’re safe from asteroid Apophis. Ever since its 2004 discovery, asteroid 99942 Apophis has threatened planet Earth. Asteroid Apophis has been measured […]

It’s one of Einstein’s most bizarre predictions. And it’s true. There’s no such thing as absolute time. No matter where you are, how fast you’re moving, or how strong the gravitational […]

Both views are equally spectacular, but unequally informative. Every so often, a creative amateur project highlights our professional achievements. This mosaic shows the region between the constellations of Cygnus and […]

Is a proton fundamentally more ‘quarky’ or ‘gluey’ in nature? One question that every curious child winds up asking at some point or other is, “what are things made of?” Every […]

A tiny layer of microscopic dust is the only reason it appears red. When we look out at our planet Earth from space, we see a myriad of diverse colors. The […]

It’s how successful our current theories are. Some 500 years ago, there was one scientific phenomenon that was, without controversy, extremely well-understood: the motion of the celestial objects in the sky. […]

Even before the Big Bang, energetic radiation was always present. When it comes to the physical Universe, the notion of “nothing” may truly be possible only in theory, not in […]

Our views from the red planet’s surface are more spectacular than ever. Ever since the earliest spaceflight, humanity has reached for Mars. This photo composite shows Meande Ring, a river on […]

It could have had any curvature at all. So why is it flat? What is the shape of the Universe? If you had come along before the 1800s, it likely never […]

The Crab Nebula goes back to 1054, opening a window into our cosmic past. On July 4, 1054, Chinese astronomers recorded a “guest star” in the Taurus constellation. A ‘guest star’ […]

‘Reductio ad absurdum’ won’t help you in an absurd Universe. Throughout history, there have been two main ways humanity has attempted to gain knowledge about the world: top-down, where we […]

The definitive answer requires better, unbiased data. Despite all the advances that have occurred in human history, one extraordinary puzzle still remains right in our own backyard: we aren’t sure how […]

Are space and time real like atoms are, or is spacetime just a calculational tool? When most of us think about the Universe, we think about the material objects that […]

Of all the injustices in Nobel Prize history, her 1957 Nobel snub is the most egregious. One of the biggest scientific revolutions of the 20th century was the discovery of […]

The concept of ‘relativistic mass’ has been around almost as long as relativity has. But is it valid? No matter who you are, where you are, or how quickly you’re moving, […]

Thou shalt not conclude “aliens” from insufficient data. When it comes to what’s out there in this Universe, perhaps the only thing that’s greater than our cosmic ignorance is the […]

Avi Loeb says it’s aliens. Every other astronomer disagrees. Here’s why. In 2017, an astronomical event occurred that was unlike any other: for the first time, we observed an object that […]

Time always moves in the same direction, but what if the Universe were contracting? As we step forward in time, a number of things always seem to happen together. Objects […]

The night sky is already noticeably different, and bigger changes are ahead. For all of human history until the launch of Sputnik, the only objects in the night sky were naturally […]

A new survey, the DESI Legacy Imaging Survey, has found more lenses than all others put together. One of Einstein’s most revolutionary predictions is that mass bends light. During a […]