Weltall
11 cards from across every topic, each citing a source. Tap one to open it in the feed.
- A probe from 1977 is still phoning home.
Voyager 1 launched in September 1977, flew past Jupiter and Saturn, and in 2012 became the first human-made object to …
- A teaspoon of this weighs more than a mountain range.
When a massive star explodes, its core can collapse into a neutron star: about 1.4 solar masses squeezed into a sphere …
- Astronauts on the ISS see 16 sunrises a day.
The International Space Station orbits about 400 kilometres up at roughly 27,600 km/h. One lap takes a little over 90 …
- On Venus, a day lasts longer than a year.
Venus needs 225 Earth days to orbit the Sun but 243 Earth days for a single spin on its axis. It also rotates …
- The Moon drifts 3.8 centimetres farther away every year.
Apollo astronauts left laser reflectors on the Moon. Since 1969, observatories have fired laser pulses at them and …
- The Sun loses four million tonnes every second.
In the Sun's core, about 600 million tonnes of hydrogen fuse into helium every second. Roughly 0.7 % of that mass …
- The first black hole photo needed an Earth-sized telescope.
In 2019 the Event Horizon Telescope revealed the shadow of the black hole in galaxy M87, 55 million light-years away …
- The gold in your ring was forged when dead stars collided.
Stars fuse elements in their cores only up to iron. Heavier ones like gold, platinum and uranium need extreme floods of …
- The solar system's tallest mountain is too flat to admire.
Olympus Mons on Mars rises about 22 kilometres, roughly two and a half times the height of Everest. Its base spans …
- The sunlight on your skin is eight minutes old.
Light travels through vacuum at exactly 299,792,458 metres per second. That number isn't measured, it's fixed: since …
- You cannot see the Great Wall from the Moon.
The Moon averages 384,399 kilometres away – from there the wall would look as wide as a hair seen from three …