It wasn’t just the Milky Way and Andromeda two billion years ago. Here in the Local Group, our two largest galaxies dominate: Andromeda and the Milky Way. Our Local Group of […]

Our best physical theories predict that a multiverse exists. But if we can’t test it, is it really scientific? The Universe is all there ever was, all there is, and […]

A new set of images from NASA’s Chandra X-ray observatory shows us what we’ve never seen before. The Pillars of Creation, 7,000 light years away in the Eagle Nebula, represents one […]

If we know how big the observable Universe is, why can’t we figure out how big the unobservable part is? 13.8 billion years ago, the Big Bang occurred. The Universe was […]

There’s a halo of dark matter permeating every galaxy, and that means its particles pass through us, too. The Universe, despite all the planets, stars, gas, dust, galaxies, and more we […]

Forget the spectacular explosions we create here on Earth. The Universe outdoes us in every way imaginable. Forget mere chemical reactions; in space, matter-energy conversion creates unprecedentedly powerful explosive events. […]

There are only two perfect numbers that fit on the calendar: 6 and 28, making June 28th Perfect Number Day. Find out what makes a number perfect, and why they matter. […]

Intelligent aliens, if they exist in the galaxy or the Universe, might be detectable from a variety of signals: electromagnetic, from planet modification, or because they’re spacefaring. But we haven’t […]

The Universe is expanding, but different techniques can’t agree on how fast. No matter what, something major has got to give. Look out at a distant galaxy, and you’ll see it […]

When it comes to the Solar System, all we have left are the survivors. At last, that might be enough to know what happened 4.5 billion years ago. We know what […]

And if we did, what would happen if you fell in? Out in the countryside of rural America, you can find all sorts of attractions that are too-good-to-be-true. One of the […]

Everyone in the Universe needs a break sometimes. They say that all work and no play make Jack a dull boy, and with very few exceptions, I’ve been working hard […]

Here on Earth, all the right conditions occurred for intelligent life to come about, but the nearest aliens, if they’re on another world, are light years away. But it doesn’t […]

In 2015, the ultra-distant galaxy CR7 was measured to have hydrogen and helium, but no carbon or oxygen. With new ALMA observations, there’s carbon after all. As brilliant as our Universe’s […]

‘Luck’ is the wrong word. The Universe cooperated, but we gave ourselves the opportunity by being prepared. It was already 28 years ago that the Hubble Space Telescope was launched […]

Just one equation relates the expansion of space to all the matter and energy we have. If you know this, you can know the fate of the Universe. Last week, […]

If it can stretch the Universe from the size of a subatomic particle to billions of light years in a fraction of a second, why doesn’t Einstein’s relativity forbid it? When […]

Among the general public, people compare it to the aether, phlogiston, or epicycles. Yet almost all astronomers are certain: dark matter and dark energy exist. Here’s why. If you go by […]

It took the Universe 9.2 billion years to create the Earth, and another 4 billion for complex life. Could we have gotten there faster? The story of how the Universe came […]

Even with nothing new falling into it, our radius is increasing with every second that goes by. It’s no big secret that galaxies grow over time. The force of gravity is […]