A gravity fact every day of the month
On the Moon, a hammer and a feather hit the ground together. An astronaut tried it in 1971. One fact like that lands in your calendar every morning.
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Pluto's surface gravity is about 0.62 m/s², around 6% of Earth's.
A belly-down skydiver reaches a terminal speed of roughly 200 km/h (about 120 mph).
GPS satellite clocks gain about 38 microseconds a day relative to the ground, mainly because gravity is weaker up there. The system corrects for it.
Gravity is a little weaker at the equator (about 9.78 m/s²) than at the poles (about 9.83 m/s²).
The Sun holds about 99.8% of all the mass in the solar system.
Changes in gravity travel at the speed of light. If the Sun vanished, Earth would keep orbiting for about 8 minutes.
The Moon drifts about 3.8 cm farther from Earth every year. Laser reflectors left by Apollo measure it.
Gravity is the force everyone feels and almost nobody thinks about. These 31 facts cover planets, black holes, astronauts, GPS satellites and the history of the idea, from Newton's Principia to LIGO's first gravitational-wave detection.
The figures come from standard references such as NASA planetary fact sheets. They're rounded so they're easy to remember and repeat at dinner.
Fluxo: Gravity Runner: A one-tap gravity-flip arcade runner; plays offline.
Get it free on the App StoreHow to add it on iPhone
- Open this page in Safari on your iPhone.
- Tap Add to iPhone Calendar, then tap Subscribe.
- Tap Add. Events appear in the Calendar app within a minute.
On a Mac, the same button opens Calendar. In Google Calendar, use the Google button, or paste https://honestlittleapps.github.io/calendars/gravity-fact-of-the-day-calendar/gravity-fact-daily.ics into Other calendars › From URL.
Questions
Are the numbers exact?
They're rounded from standard published values (for example, NASA planetary fact sheets) to two or three significant figures.
Good for school?
Yes. Each fact works as a science lesson starter for upper elementary and middle school.
What's Fluxo?
A one-tap gravity-flip arcade runner that plays offline.
Is this calendar free?
Yes. It costs nothing, needs no account and shows no ads. You can unsubscribe at any time.
How do I remove it from my iPhone?
Open the Calendar app, tap Calendars at the bottom, tap the ⓘ next to this calendar and choose Delete Calendar. Or go to Settings › Apps › Calendar › Calendar Accounts › Subscribed Calendars.
Other ways to get it
A daily page you can add to your Home Screen · an RSS feed · a free widget for your website · the press kit