How dark is space?

October lecture from the Space Telescope Science Institute

Will update with link and notes

Space Telescope Science Institute Lecture
8th October 2021 - How Dark is Space

This lecture looked at light in the universe, and asked how much light is there compared to Darkness.

The lecture looked at NGC 1052 DF2, which was refereed to as DF2 during the lecture. This is a galaxy, but one that has no dark matter which is unusual.

When looking at space and light, you need to take in to account the fact that given the billions of stars and galaxies. You are going to get some that are in front of each other (which make some less visible)… Another thing looked at here was the Hubble deep field, where the telescope was pointed at the same location for 11 days. The resulting pictures was a huge number of light sources each one being a galaxy.

Hubble of course can’t pick up everything that is out there.

As light is made up of different components, visible light, Ultra violet, xrays, Infra Red, Radio etc. So the subject of the research being undertaken is how much visible light there is (Cosmic Optical Background) This is where the New Horizons probe comes in, current problem with earth and more local telescopes is that they pick up light from different sources, including reflections from dust etc.

So once you have taken in to account known sources you are left with unknown sources of light.

New horizons is currently on the edge of the solar system, about 50 AU, 1 AU being the distance between Earth and the Sun. So they are looking for light that they can’t explain and they have found a gap between the observable light and light they can account for. This is cutting edge research, as right at the end of the lecture, the presenter says he is off to examine the latest data set of results.

In order to rule out sources of light the team even had to take in to account any reflections from the probe itself. So very complex process.

So the work is still on going, and, as they say “Watch this space”.

Next lecture topic is TBC however in December there is a count down to the launch of the JWST.