Weight on Other Worlds

Enter your weight. Find out what you'd weigh on Jupiter, the Moon, or a neutron star.

You vs. a Light Beam

You run 100m in your best time. In those same seconds, how many times has light circled the Earth?

Light Travel Guess

Pick a destination. Guess how long light takes. Then get roasted by the universe.

Your Cosmic Birthday

The Solar System orbits the galaxy at 828,000 km/h. Since you were born, where are we now?

Relativity Clock

Fly near light speed for a year. Come back. Everyone you knew is old or gone. How much younger are you?

Interstellar Delivery

Your Amazon package is going to Mars. Pick a shipping method. Find out when it actually arrives.

You Are Made of Stars

Every atom in your body was forged in a dying star. How many? Enter your weight and find out.

Drake Equation Lite

How many civilizations in the Milky Way could be sending us messages right now? Play with the variables.

If You Could Hear the Sun

Space is a vacuum. Sound can't travel. But if it could, what would the Sun sound like? And when?

The Cosmic Calendar

If 13.8 billion years fit into one year. When did humans show up? Last 14 seconds. Ouch.

.

In The Time You Blink

You blink for 0.3 seconds. In that instant, how far has light traveled? To the Moon? Around Earth?

The Pile of Humanity

Pile all 8 billion humans into one heap. How big is it? Smaller than you think. Way smaller.

Jump on Other Planets

How high can you jump on Earth? Find out how high you'd soar on the Moon, Jupiter, or a comet.

How Far Have You Walked?

Enter your age. See how many millions of steps you've taken. Compare it to the Moon. It's depressing.

The Solar System on Your Desk

If the Sun were a basketball on your desk, where would Neptune be? Drag. Zoom. Feel the emptiness.

Neutron Star Spoon

One teaspoon of neutron star material weighs as much as what? Pick your spoon size and find out.

Cosmic Noise

A synthesized soundscape of deep space. Put on headphones. Feel small.

Next Eclipse

When is the next solar or lunar eclipse visible from where you are? Real NASA data.

Escape Velocity

How fast do you need to go to leave each world? Earth: 11 km/s. Neutron star: light speed.

Age on Other Planets

Enter your Earth age. See how old you'd be on Mercury, Mars, Jupiter. Real orbital periods.

Survive on Other Planets

No spacesuit. No air. Just you dropped on a random world. How long do you last?

How Fast Are You Moving?

You think you are sitting still. Enter your latitude and discover your actual speed through space.

What Time Is It on Mars?

Mars has its own clock. A sol is 24h 39m. Watch the red planet time live.

Asteroid Impact Damage

Enter an asteroid size. Find out if it ruins your day, your city, or civilization.

Black Hole Spaghettification

Enter your height. Find out when the tide turns you into cosmic noodles.

Hit the Sun vs Escape

It takes more energy to crash into the Sun than to leave forever. Why?

Re-Entry Heat Calculator

Coming home at 11 km/s means 5,000 degrees. How hot does your shield get?

Gravity Assist Calculator

Why does reaching Saturn take 4 planetary flybys instead of one rocket?

What If Earth Spun Faster?

Speed up the rotation. Watch gravity weaken, storms go wild, and the equator bulge.

If the Moon Were Closer

Drag the Moon toward Earth. Tides flood, eclipses turn permanent, and the Moon breaks apart.

How Far Have We Gone?

Voyager 1 has flown for 47 years. It is still, astronomically speaking, in the driveway.

What If the Moon Vanished?

No more tides. Days spin in 8 hours. Earth tips over. No more eclipses. Here is what happens.

How Far to the Horizon?

Stand on a beach. The ocean ends somewhere. That line is not infinite. It is the curve of the Earth eating your view.

Fall to the Center

Dig a hole through the Earth. Jump in. 42 minutes later you are on the other side. Then you fall back. Forever.

How Many Stars Can You See?

You grew up seeing 5 stars. Your ancestors saw 4,000. The Milky Way is invisible to most people on Earth.

Drive to the Moon

The Moon is 384,400 kilometers away. At highway speed, that is a 160-day road trip. If there was a road.

The Moon Is Leaving You

The Moon drifts 3.8 cm every year. Enter your birth year and see how much closer it was when you arrived.

Galaxy Years

The Sun takes 230 million years to orbit the Milky Way. Enter your age — you have not completed one orbit yet.

The Sun's Fuel Bill

The Sun loses 4.26 million tonnes of itself every second. Enter your age — that is your bill.

Cosmic Expansion Ruler

Space is stretching your arm apart right now. Enter a distance — see how fast dark energy pulls it.

Cosmic Brakes

The universe braked for billions of years before dark energy hit the gas. See when expansion flipped.

Hubble Tension

Two teams measured the expanding universe and disagree by 8%. Enter a redshift and see the fight.

Black Hole Temperature

Black holes run hotter as they shrink. Enter a mass — a Sun, an Earth, a mountain — and read its Hawking temperature.

Orionids Meteor Watcher

Every shooting star tonight is a leftover from Halley's Comet. Enter your sky darkness, latitude, and watch hours — count your meteors.