Space

Why does the moon look so much bigger when it is near the horizon than when it is high up in the sky? This question has been pondered for hundreds if not thousands of years, and is commonly referred to as the moon illusion.

Nobody's nose knows better than NASA's George Aldrich. He's the longest-serving member of the space agency's odor panel, which basically sniffs and smells everything that goes up into space.

By John Donovan

Winter is the perfect time to look for Orion's Belt in the Northern Hemisphere. If you're new to stargazing, we'll show you how to find it.

By Valerie Stimac

You might call it a Christmas miracle. Jupiter and Saturn will align so closely they may look like a double planet. The last time we saw this was in 1226.

By Valerie Stimac & Desiree Bowie

The Quadrantids are a short but powerful meteor shower that shows up in early January. How can you glimpse it?

By Valerie Stimac

A magnetar is a neutron star with a super-strong magnetic field. Astronomers consider them among the scariest objects in the universe, but why?

By Valerie Stimac

Less than 100 miles from Las Vegas, is the most famous secret military installation on the planet: Area 51. For decades, the U.S. government refused to acknowledge it existed. But now, the secret is out.

By Jonathan Strickland & Patrick J. Kiger

At a drag race, I once saw a rocket car that was supposedly powered by spraying hydrogen peroxide on a silver mesh. The resultant reaction produced huge amounts of pure white smoke and apparently enough thrust to propel the car rapidly down the track. Does hydrogen peroxide really react with silver that way?

Apollo astronauts left a lot of stuff behind on the moon. Can you see any of that from Earth, even with a telescope?

By Valerie Stimac & Sascha Bos

If "nature abhors a vacuum," then why doesn't the vacuum of space suck away all of the Earth's atmosphere?

It turns out that measuring the distance to a star is an interesting problem! Astronomers have come up with two different techniques to estimate how far away any given star is.

In science, we are learning about the atmosphere. It protects us from meteors because it burns them up. So, why doesn't the space shuttle burn up?

Can the curvature of the Earth only be seen from outer space? If you didn't know that the Earth is a sphere, there are three common observations you could use to convince yourself that it is.

Believe it or not, the hardest part of space exploration is getting a spaceship off the ground. Explore the basics of propulsion and learn about both solid-fuel and liquid-fuel rocket engines.

By Marshall Brain

The hunt for exoplanets, planets orbiting sun-like stars, is on! Thanks to new equipment, NASA has spotted thousands of them. But which ones might be able to handle life?

By William Harris & Jacob Silverman

The Voyager spacecraft use 23-watt radios. This is higher than the 3 watts a typical cell phone uses, but in the grand scheme of things it is still a low-power transmitter. The key to receiving the signals is therefore not the power of the radio, but a combination of three other things.

If I was on the moon and the earth was black (no lights were on) and a flashlight was turned on facing the moon, would I see the light? If I couldn't, would there be any way to detect any residual matter that came from the light on Earth or does light die after a certain distance?

A new space race is on -- who will be the first to build a space hotel? One company has gathered 3 billion dollars to do just that. Find out what life in a luxury space hotel might be like.

By Jacob Silverman

Even though it's tiny compared to the rest of the universe, Earth is a complex planet that, so far, is the only one we know of that sustains life.

By Kathryn Whitbourne & Mark Mancini

Of course we want to go to Mars. Until we figure it out though, roving robots with names like Spirit, Opportunity, Sojourner and Curiosity are our best bet for digging up dirt on our nearest planetary neighbor. Want to go along for the ride?

By Marshall Brain & Kate Kershner

Jupiter is the largest planet in the solar system. Big as this gas giant is though, next to the sun, it's still small.

By Mark Mancini

Mercury is the closest planet to the sun, and it's the smallest in the solar system. So why does it have longer days than we have on Earth?

By Mark Mancini

While we generally picture the sun and planets when thinking about our solar system, it also consists of comets, asteroids and hundreds of moons.

By Nicole Antonio

Neptune is the eighth planet from the sun and one of the coldest. It also has supersonic winds that are the fastest in the solar system.

By Mark Mancini

Uranus is the seventh planet from the sun and sits on an axial plane tilted at a jaw-dropping 97.7-degree angle. And yes, Uranus does actually stink.

By Mark Mancini