OUR UNIVERSE

On Aug. 21, 2017, people across the United States will see the sun disappear behind the moon, turning daylight into twilight, causing the temperature drop rapidly and revealing massive streamers of light streaking through the sky around the silhouette of the moon. On that day, America will fall under the path of a total solar eclipse. The so-called Great American Total Solar Eclipse will darken skies all the way from Oregon to South Carolina, along a stretch of land about 70 miles (113 kilometers) wide. People who descend upon this "path of totality" for the big event are in for an unforgettable experience. Who Can See It? Lots of people! Everyone in the contiguous United States, in fact, everyone in North America plus parts of South America, Africa, and Europe will see at least a partial solar eclipse, while the thin path of totality will pass through portions of 14 states.   Image Credit: NASA’s Scientific Visualization Studio Wh...

The universe is full of stuff that can kill you. At the top of that deadly list? Gamma-ray bursts, which explode with the energy of a hundred trillion nuclear weapons per second for longer than the universe has existed. They're pretty powerful, is what we're saying. Learn more about these monstrosities in the video below.

A faraway star's mysterous dimming was most likely caused by comets, a new study suggests — though it doesn't rule out the much-ballyhooed possibility of an "alien megastructure" in the system. Observations by NASA's planet-hunting Kepler space telescope revealed that the star KIC 8462852, which lies about 1,500 light-years from Earth, dipped in brightness dramatically in 2011 and 2013, dimming by up to 22 percent. Such deep brightness dips puzzle astronomers, who have advanced a number of possible explanations, from a gigantic asteroid collision to a cloud of broken-apart comets to an enormous energy-collecting structure built by an advanced alien civilization. (The alien-megastructure hypothesis is unlikely but nonetheless warrants consideration, many astronomers have said.) Artist's illustration showing a star behind a shattered comet. Credit: NASA/JPL-Caltech ...

A photon leaps off the sun and, about 500 seconds later, bounces off our Earth. Light has been dancing and rebounding from faraway and nearby celestial objects for more than 13 billion years. It's time you caught some of it for your very own. That's what telescopes do; they gather light. But which telescope you choose to collect that radiance will vary according to your needs and budget. Our editors have selected a few of the best options in four categories. Click on each to read a review of the telescopes in these groups: Best Hobbyist Telescopes for Serious Sky watchers Best Small, Portable Telescopes for Travelers and City-Dwellers Easiest Telescopes for Beginners (Easy to Use) Best Inexpensive Telescopes (A Great Gift Idea) Space.com Editors have selected 12 Great Telescopes in 4 Categories. Are you a traveler? Student of the sky? On a budget? Live in a small home? Do you like digital tech? Or prefer an analog approach? ...

And 'how much longer until a new discovery shouts it out?' asks the Science @ NASA video series. In July 2014, NASA announced the discovery of Kepler 452b, a planet slightly larger than …Read More » Earth that resides in the habitable zone of its solar system. It is 6 billion+ years old, (older than Earth) allowing for plenty of time for life to develop.

So how thick is what we call sky? Well, you'd think, looking up, that there's so much blue up there it's got to go on for hundreds and hundreds of miles. But it doesn't. Looking at this photo, you can see that the ring of atmosphere around the earth is cellophane thin...a wisp of gas. It's a little thinner at the poles and thicker near the equator, but the "sky" is about 250 miles wide (or up), the distance, roughly, between New York City and Washington, D.C. Which means — if Amtrak could run a "Sky Chief" straight up and handle the spin — you could chug to the very edge of space in three and a half hours. But that's not the cool part. In the 1940's, the great illustrator Eric Sloane did a cross-section of the atmosphere that surrounds our planet. He observed that we live in a sea of air, and we, like lobsters, are at the bottom: Eric Sloane/Dover Publications Then he took a closer look at that bottom piece, ...