|Helix Nebula - Unraveling at the Seams|
2) The American Academy of Poets also has a less extensive archive of poems. You'll want to select the Advanced Search option from the main page, then use the "Theme" drop down and select "Space" to find about 20 poems. Again, I've done the search already, because I'm cool like that. You also have the option to browse by title and first line, if you're looking for a particular poem.
3) The Poetry Out Loud website has an online anthology of poems that qualify for their national annual recitation contest. This archive is alphabetical by title or poet and has no browsing or filtering functions. You can, however, search the whole site using the search box in the top right corner of the site. If you search for things like "stars" or "space" or "planet" you will find links to poems, though not all of them will be. But don't overlook some of the video performances from past finalists; these have a power all their own and are worth at least a viewing. You can also listen to poetry recitations.