The top of Mauna Kea is the ideal physical site for this new, ready-to-be-built telescope. But that’s far from the only concern. For many years, astronomers have looked forward to a […]

Many of them are spinning at nearly the speed of light. When you do the math, there’s no other way it could have been. Take a look out there at the […]

What makes Uranus and Neptune-like worlds so fascinating? If you only knew. What do we really know, and what mysteries are left to solve, about the outer worlds of our Solar […]

The dream of multi-messenger astronomy is to seen an event with gravitational waves, neutrinos, and light all together. The newest candidate just might get us there. When it comes to cataclysmic […]

And it’s not because of leap seconds; it’s a fundamental property of most days. Human beings, in marking the passage of time, account for each day equally: with 24 hours. One […]

It’s not a question of could they, but have they? Here’s how we’ll find out. It’s no secret that fragments of asteroids, comets, and other spaceborne objects have been found here […]

A star orbiting past our galaxy’s supermassive black hole offered a chance to test relativity as never before. The supermassive black hole at the center of the Milky Way is the […]

A case for looking beyond the planetary scientist’s (or even the astronomer’s) definition. Ever since 2006, when the International Astronomical Union (IAU) officially defined the term planet — introducing the term ‘dwarf […]

You get out what you put in, and we haven’t truly invested in space since Apollo ended. Humanity should be an interplanetary civilization by now. There is no scientific reason that […]

Most of the Moon’s effects on Earth are small and imperceptible. But for the grunion, it’s absolutely essential. Although it’s the closest astronomical body to Earth, the Moon is still […]

Not only can’t astronomers and planetary scientists agree, but the IAU made it worse for everyone. If you were alive in 2006, you likely remember a momentous event in astronomy: […]

When stars get ejected from galaxies within massive clusters, they go where the dark matter is. Dark matter is one of the greatest mysteries in the Universe, displaying its effects in […]

General Relativity has nothing to do with light or electromagnetism at all. So how to gravitational waves know to travel at the speed of light? There are two fundamental classes of […]

If you think nothing can move faster than light, check out this clever way to defeat that limit. Nothing can move faster than the speed of light. When Einstein set forth […]

Here are four separate ways you can prove it, even 50 years after-the-fact. 50 years ago, on July 20, 1969, humanity took our first footsteps on the surface of another […]

Discovered by NASA’s Chandra X-ray observatory, it’s powered by a supermassive black hole. 2019 marks 20 years of NASA’s Chandra, humanity’s most powerful X-ray observatory. Artist illustration of the Chandra X-ray […]

The summer solstice is the longest day of the year, but doesn’t have the earliest sunrise or the latest sunset. Here’s why. The length of a day on planet Earth might […]

It’s where Earth’s axial tilt with respect to the Sun is most extreme. Here are the consequences. Today is June 21st, 2019: the day of the solstice. Although there are […]

Some galaxies might not have any dark matter. Here’s why you should care. There are two assumptions that everyone makes about the Universe for extremely good reasons, but they might not […]

A vacuum cleaner is the wrong picture. Time to bust that myth. There are no classes of object in our Universe more extreme than black holes. With so much mass present […]

At the core of the largest star-forming region of the Local Group sits the biggest star we know of. Mass is the single most important astronomical property in determining the lives […]

Two independent techniques give precise but incompatible answers. Here’s how to resolve it. If you didn’t know anything about the Universe beyond our own galaxy, there are two different pathways you […]

An entire Universe of possibilities await stars like our own, even after they run out of fuel. One of the most profound rules in all the Universe is that nothing lasts […]

Has the mystery really been solved? Doubtful. The real science goes much deeper. For perhaps the last year or so, a small galaxy located not too far away has captivated the […]

There aren’t any holes in the Universe at all. What actually exists is far more interesting. Somewhere, far away, if you believe what you read, there’s a hole in the […]

If we could see in three dimensions instead of two, we’d never have thought otherwise. Perhaps the most famous sight of a dying star is the Ring Nebula, discovered in […]

13.8 billion years isn’t close to enough time, but if we wait long enough, even our Sun will become one. The Big Bang happened approximately 13.8 billion years ago, and it […]

The solar eclipse of May 29, 1919, was the nail in the coffin of a Newtonian Universe. On May 29, 1919, the world changed forever. For hundreds of years, Isaac […]

Everything on Earth is made of atoms and their building blocks. Without this one rule, they’d never make anything interesting. Take a look around you at everything on Earth. If […]

Imagine how different our understanding of the Universe would be if we saw nothing beyond the Milky Way. Our corner of the Universe was gifted with a plethora of bright, nearby […]