Featured · Space
Black Holes, Explained Without the Math
They don't suck things in, they aren't really holes, and we have now photographed two of them. A plain-language tour of the strangest objects in the universe.
Space · Physics · Planet Earth
The universe, one question at a time.
Deep Field turns big scientific ideas into clear, illustrated stories. Every explainer is checked against primary sources, and you won't need a physics degree to follow it.
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Space fact of the day
A day on Venus (243 Earth days) is longer than its year (225 Earth days).
Fresh from the observatory
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Space
Why We Only Ever See One Side of the Moon
The Moon does spin, exactly once per orbit. Tidal locking, the "dark side" myth, and why Earth's days are getting longer.
Technology
Inside the James Webb Space Telescope
A gold mirror 6.5 metres wide, a sunshield the size of a tennis court and an orbit 1.5 million km away. Here is how Webb works.
Physics
How Your Phone's GPS Depends on Einstein
Without relativity corrections, GPS positions would drift by about 10 km a day. Here is where those 38 microseconds come from.
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Space calculators
Put yourself on another planet. All three tools run right in your browser and don't collect any data.
Your age on other planets
On Mercury you'd be four times older; on Neptune you'd still be waiting for your first birthday.
Your weight on other worlds
From the Moon to Jupiter: see how much you'd weigh under the gravity of ten different worlds.
Light travel time
How long does light take to reach the Moon, Mars or Voyager 1? Includes a live estimate for Voyager.
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