APOD: 2020 July 26 – A Flight through the Hubble Ultra Deep Field

Good morning, Rallypoint. Today's Astronomy Picture of the Day (APOD) is titled "A Flight through the Hubble Ultra Deep Field." You've probably seen the composite image of the Hubble Ultra Deep Field (HUDF) released in 2006. The HUDF imagery was taken in a section of the sky with a low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. That section of the sky is located southwest of Orion in the southern-hemisphere constellation Fornax.

Here's where you need to let your imagination kick in. Even at the speed of light (186,000 mi/sec), it takes a long time for light to transit the universe. How long? Cosmologists estimate the age of the universe to be 13.787 billion years, plus or minus 20 million years. The smallest, reddest galaxies in the HUDF may be among the most distant known, existing when the universe was just 800 million years old. In other words, the light has been traveling our direction for nearly 13 billion years.

The composite HUDF required 800 exposures taken over the course of 400 Hubble orbits around Earth. The total amount of exposure time was 11.3 days, taken between Sept. 24, 2003 and Jan. 16, 2004. The 800 exposures are assembled into the 58-second video clip that makes up today's APOD. Enjoy.