it may sound like a silly question, but when i was showing people pictures from james webb, i got multiple people ask me what a nebula is, so i thought i’d give a quick explanation!
nebulae (or nebulas- both are correct) are massive clouds of gas and dust in space, which can stretch hundreds of light years across. these clouds are often known as “stellar nurseries,” as the gasses, over millions of years, coalesce into young stars due to gravitational forces.
similarly, a planetary nebula (which, despite the name, has nothing to do with planets) is also a cloud of gas and dust. although, instead of being a nursery for young stars, it’s the gasses cast off of the outer layers of a dying star as it collapses.
most nebulae are very far away, however, the orion nebula (located in the constellation orion) is visible to the naked eye, and appears as the sword in orion’s belt.
TIL anyone who's going to overwinter in Antarctica has to have had their appendix out. Because removing an appendix that's not causing any trouble just as a precaution is way better than having one that's about to burst when you're on the ass-end of the planet with no way to be rushed to a hospital if shit gets real.