“Should they strike, each of them has an energy at impact equal to all of the nuclear weapons on Earth combined."

There are over 100 known elements in the periodic table. These 8 ways of making them account for every one.

But the upcoming James Webb Space Telescope compels us to add, “so far.” Beginning with its 1990 launch, NASA’s Hubble Space Telescope revolutionized our conception of the Universe. This photo of […]

Once merely a theoretical curiosity, they might be the key to understanding so much more. Out of all of the known particles — both fundamental and composite — there are a whole slew of properties […]

Whatever’s lurking out there, it isn’t all, or even mostly, normal matter. When it comes to the Universe, it’s only natural to wonder what, exactly, it is that makes everything up. […]

“Hubble’s Law” is only an approximation, and breaks down when we need it most. From anywhere in the Universe, you can choose to look out at any other galaxy that’s present. […]

It happened more than once, and needed to. Here’s why. If there’s one thing you can be certain about when it comes to outer space, it’s that it’s transparent, not opaque, […]

Hubble, our greatest space-based observatory today, is just the beginning. The Hubble Space Telescope has been astronomy’s most revolutionary observatory in history. The stars and galaxies we see today didn’t […]

Galaxies can have regions both hotter and colder than the background radiation of the Universe. When we talk about the depths of space, we get this picture in our heads […]

We’ve already observed three cases where it’s happened. When you look at an object in space, it’s pretty easy to tell if it’s a star or a planet. Stars are […]

When you mix science with speculation, you get speculation. But the underlying science is still real. Whenever you hear the phrase, “it’s just a theory,” it should trigger alarm bells in […]

It could evolve, strengthen, decay, or not be alone. Our known Universe contains matter, radiation, and dark energy. While matter (both normal and dark) and radiation become less dense as […]

The raw ingredients just weren’t there. Thankfully, their predecessors were. Here on Earth, our planet practically overflows with life. After more than 4 billion years, life has spread to practically […]

And the one step we can take to show extraterrestrials we’re figuring it out. Every year, Earth’s meteor showers accomplish two important tasks. This composite photograph shows a large number of […]

The ‘final parsec problem’ is still a mystery for astronomers. When it comes to black holes in the Universe, we know there are at least two major types. There are […]

It peaks the nights of August 11–13, but it’s no longer the year’s most reliable meteor shower. Every year, beginning in mid-July, planet Earth commences passing through an enormous debris […]

At 35 light-years away, it’s also the 2nd coolest, 2nd widest planet ever found. Despite discovering more than 4000 exoplanets, most remain obscure. Although more than 4,000 confirmed exoplanets are known, […]

Even a small merger can trigger so much more than we realize. Practically every galaxy in the Universe has a supermassive black hole at their core. Ranging from millions to many […]

And, if we have one, how close are we to it? No matter which direction we look in, or how far away our telescopes and instruments are capable of seeing, the […]

Despite the recent headlines, it’s an extraordinarily unlikely proposition. Have you ever wondered, if it were possible to travel through space straight ahead as quickly as you could imagine, if […]

Hubble’s still going strong after 31+ years. James Webb will never make it that long. Every decision that’s made — in both astronomy and in life — comes with its own set of pros and […]

50% of stars are in Sun-like ‘singlet’ systems. The planetary nebulae we see just don’t line up. Around 7 billion years from now, our Sun’s life will end. As the Sun […]

If our nearest star has an Earth-like planet, here’s how we’ll see it. As seen from up close, the signs of not only life, but our intelligent, technologically advanced human civilization […]

The contact binary system KIC 9832227 is worth another look. Astronomers have seen some incredible occurrences across space and time. The nova of the star GK Persei, shown here in an […]

With sodium-sensitive eyes, we’d see it every new Moon. With no detectable gases, the Moon appears to be atmosphere-free. The Moon as seen from a view above the majority of Earth’s […]

The rarest stars in the Universe are the ones we need the most to make humanity possible. Like everything in the Universe, stars are born, they live a little while, […]

Planets are either rocky, like Earth, or gas-rich, like Neptune, with no in-between. What are the different types of planets that exist in the Universe? If all you could see […]

An almost 40-year-old theory finally has ‘smoking gun’ evidence for it. During most of their lives, stars burn stably, changing imperceptibly. The rotten egg nebula, at lower right (and shown in […]

Despite all the challenges, Hubble has vindicated this discovery. Practically everywhere we look in the Universe, the large-scale objects that we see — small galaxies, large galaxies, groups and clusters of galaxies, […]

Despite Betelgeuse’s recent faintening and brightening, I’d bet on these stars instead. Betelgeuse, a nearby red supergiant, will someday explode. The black hole at the center of the Milky Way should […]