repost from @allspaceconsidered : It’s the last day of #summer! Who is ready for #autumn? Autumn begins in Earth’s northern hemisphere at 6:04 p.m., PDT, tomorrow. Spring begins in the southern hemisphere at the same time. The September/autumnal equinox is the moment when the Sun crosses the celestial equator (the projection of Earth’s equator into space) from north to south. #GriffithObservatory #lookup #observeandponder