A Galaxy Far, Far Away

   With a combination of the Hubble Space Telescope, the Spitzer Space Telescope, and a technique called gravitational lensing, NASA astronomers have been able to image what is so far the most distant galaxy. This galaxy is estimated to be somewhere around 13.2 billion light years distant, and at that distance the age of the galaxy would be about 200 million years old.
   Gravitational lensing is the term used to describe what happens when light from distant objects passes another celestial object like a galaxy or a cluster of galaxies lying in our line of sight direction – between us and the more distant object. That light is magnified and refracted by the gravitational field of the ‘between’ object. Think of this as being able to use a magnifying lens to enlarge the object being viewed.
   In a related topic the galaxy may actually be about 30 feet closer. Huh?!
   At the recently ended International Astronomical Union (IAU) meeting in China members adopted a resolution that agrees with Resolution B2 approved in 2009 which established the Astronomical Unit (au) as a distance of 149,597,870,700 meters, ± 3m (92,955,807.273 miles). This is the mean, or average Earth to Sun distance, or as my students should know, is the semi-major axis of Earth’s slightly elliptically shaped orbit. However they have learned that the value for 1 au is 149,597,870,691 meters. That is a whopping 9 meter (29.5 feet) difference from the IAU’s newly adopted value.

1 thought on “A Galaxy Far, Far Away

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.