Saturday marks the 20th birthday of the Hubble Telescope launch. Specifically, April 24, 1990 was the launch date and to remember the date, Google posted a special logo on their home page. The logo is now live at Google Australia where it is already Saturday.
Here is a picture:
The neat part is that if you click on the planets, it takes you to Google Sky. I should note that NASA and Google teamed up to make Google Sky - so this does make logical sense.
Forum discussion at Google Web Search Help and Google Blogoscoped Forums with a hat tip to Michel Wester.