Today was the last day of the semester in astronomy. I showed three of my favorite images of all time as a part of our discussion of cosmology in class. Presented with minimal comment, here they are:
WMAP all-sky image of the cosmic microwave background. The difference in temperature across the entire sky as shown in the above map is less than 400 microKelvin!
The above image is the Hubble Deep Field. This was taken in December 1995 after the Hubble images a patch of the sky that had apparently nothing in it. After 100 hours of exposure time, the assembled photo showed about 3000 distant galaxies. This image has reshaped how we view the universe.
This is an image taken by the Voyager 1 probe. The spot in the photo is what Carl Sagan refers to as the "Pale Blue Dot". It's what the rest of us call Earth.
I've shared this video that a student made for astronomy class before, but it's worth posting here again: