Science Facts

100 readers

3 users here now

Welcome to Science Facts Community, a place for rare discoveries, space, ancient mysteries, natural wonders, and mind-blowing scientific realities.

Share fascinating science facts, shocking discoveries, and credible posts that spark curiosity about our universe.

Rules:

• Be kind and respectful

• Post with a source/article or give clear info

founded 4 months ago

What is an astronomical unit (AU)? (sciencecards.org)

submitted 1 month ago by stuartml@piefed.social to c/ScienceOnlyFacts@lemmy.world

1 comments fedilink hide all child comments

The astronomical unit (or AU) is defined as approximately the mean distance between the Earth and the Sun. It is defined as 149,597,870,700 meters or approximately 93 million miles. At this distance, it takes slightly more than 8 minutes and 19 seconds for light to travel between the Sun and the Earth (or 1 AU). AU is one method of measuring distances within the Solar System. Light-Seconds (the distance that light travels in free space in one second, such as 1.3 light-seconds between the Earth and Moon) is also used… while Parsecs are used for large distances to astronomical objects outside the Solar System. One Parsec is 206,265 AU’s or 19.2 trillion miles.

you are viewing a single comment's thread
view the rest of the comments

[–] stuartml@piefed.social 4 points 1 month ago

There is a fun animation that goes along with light-seconds that you can see here. https://upload.wikimedia.org/wikipedia/commons/7/72/Earth_and_Moon_Size_and_Distance_scale_-_with_real-time_light_speed%21.webm