Wonder of ScienceA mesmerizing timelapse of the Sun in ultraviolet light, captured by the SDO spacecraft over the course of a month.
Credit: NASA/SDO
#sun #nasa #space #astronomy
paprikapink@wonderofscience Why is the sun surrounded by "the blackness of space"? It's right there, being The Sun. It should be *shining,* right?
Martin Vermeer FCD@paprikapink @wonderofscience The space around the Sun is very nearly a vacuum. The reason the area around the solar disc is bright when seen from the Earth is scattering in the Earth's atmosphere. Rise above the atmosphere, and the sky is dark to almost the solar rim. So dark even that the faintly shining solar corona can be seen!
@martinvermeer @wonderofscience Yeah. For some reason this is blowing my mind lately. Just contrasting the utter darkness of space vs the way light is such an integral part of earthly existence. Imagining life on a planet that doesn't have an atmosphere, doesn't see light like we do, or at all...how COMPLETELY different their existence would be. How would they measure the distance between galaxies without light-years? I want StarTrek to visit a world like this
@paprikapink @wonderofscience Actually you don't need light in order to have "light"years... the speed of light c is just the conversion constant between time and distance units, a bit like the ratio between feet (for height) and nautical miles (for location) in aviation. Radio waves, neutrinos, gravitational waves all move at the speed of light.
And then there is the parsec, based on measurements of the annual parallax. Already our Earthly astronomers manage without light years 😁
And then there is the parsec, based on measurements of the annual parallax. Already our Earthly astronomers manage without light years 😁
@martinvermeer
yeah that's not really my point. but thank you! 🌞
yeah that's not really my point. but thank you! 🌞