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 […]
Once only dark energy remains, empty space still won’t be completely empty. Imagine, if you dare, the very end of the Universe. The stars — past, present, and future — have all burned out. […]
The history of the Universe is forever imprinted in our own bodies. We can learn a lot about the history of the Universe just by looking at each of our own […]
If we want our conclusions to be meaningful, our data had better be robust. When it comes to the Universe, there’s a whole lot that doesn’t add up. All the matter […]
We still don’t know how it came to be this way. Every once in a while, we find an object in the Universe that completely mystifies us. For generations, astronomers have […]
5 years ago, LIGO detected our first gravitational waves here on Earth. Next decade, LISA will start seeing them from space. When it comes to gravitational waves, our terrestrial laser interferometers […]
It’s not just for Earth-like planets around Sun-like stars. Not even close. Shortly after Earth first formed first formed, life quickly took hold, thriving ever since. Both reflected sunlight on a […]
A black hole punched a hole 15 Milky Ways across in a galaxy cluster’s gas, by far the largest ‘kaboom’ ever seen. The Universe, everywhere we look, is full of cataclysmic […]
They said the “missing half” of the Universe’s matter was just found. But what they found barely makes a dent to the big picture. When we look up into the great […]
Halley’s comet only visits every ~76 years, but its meteors arrive twice each year. The most famous comet of all — Halley’s comet — returns to our inner Solar System every ~76 years. Halley’s comet […]
It’s not the only one of its kind, but it’s definitely makes no sense without dark matter. Throughout the Universe, galaxies and star clusters come in all different sizes and masses. […]
Over the past 30 years, we’ve revolutionized what we know about the Universe. But we couldn’t have done it without these lessons. On April 24, 1990, the Hubble Space Telescope rocketed […]
In 2020, we experienced the shortest ‘day’ in 50 years. Here’s the reason why. On the timescales that humans experience, there are lots of things that we consider to be extremely […]
There was less than a 2 second delay between gravitational waves and light, but that’s incredibly meaningful. There’s an important rule in relativity that — as far as we know — all objects must […]
Known as the ‘North Star,’ Polaris won’t stay that way forever. Planet Earth spins a full 360°, about its axis, every 24 hours. The Earth in orbit around the Sun, with […]
If it weren’t for a subatomic quantum rule, our Universe would be vastly different. In many ways, our views of the distant Universe are the closest things we’ll ever get […]
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 […]