Science & TechFact

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 timed the round trip, about 2.5 seconds. That gives the distance to millimetre precision: the Moon recedes roughly 3.8 centimetres per year because tidal friction transfers Earth's spin energy into its orbit.

Useful: Days grow longer as a result: 620 million years ago an Earth day lasted only about 22 hours.

Source: en.wikipedia.org

MessungMondWeltall

Difficulty:

Related cards

High tide happens on the side facing away from the Moon too.The Moon pulls the near-side water more strongly than Earth's centre, and the centre more strongly …
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 …
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 …
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 …
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 …
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. …
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 …
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 …

Keep reading

This card belongs to the topic Science & Tech. Every card is short, cites a source and can be saved – due ones come back by themselves later.

About Doomlearn · Projects · Legal notice · Privacy · Terms