# solarsystem

## December 12, 2020

Active galaxies Review

So following on from the post on December 1st this is a quick review of the active galaxies lecture from the Space Telescope Science Institute.

This lecture, presented by Dr Mitchell Revalski, is really interesting, looking at how supermassive black holes, despite their small size compared to the galaxy they reside in.

Energy from these can push away surrounding gas, and heat this up which reduces star formation as gas needs to cool to form stars.

so scales are pretty huge:

First lets look at what a light year is

Citation : spaceplace.nasa.gov

For most space objects, we use light-years to describe their distance. A light-year is the distance light travels in one Earth year. One light-year is about 6 trillion miles (9 trillion km). That is a 6 with 12 zeros behind it!


1 pc = 1 parsec = 3.26 light years

Supermassive black hole < 1pc

Bulge = 1 = 3 kpc (kilo parsec)

disk 30 kpc

circumgalactic area 50kpc

So even though these black holes are very small, they have a big influence on what surrounds them.

We know this is happening thanks to the research that led to the 2020 Nobel prize.

Well worth watching and the link is above.

Next lecture 19th Jan – The Darkest Secrets of the Universe Speaker: Raja Guhathakurta (UC Santa Cruz)

## October 30, 2020

Meteorites Talk

Just been watching a really interesting talk by Dr Tim Gregory – Meteorites from 8th October 2020 – YouTube.

This was really interesting and accessible people with both a science and non science background,

Briefly touched on how the solar system was formed, protoplanetary disks looked at the two different types of asteroids, how they are formed, what makes them up internally, and finished off with a quick look at some of the organic molecules that have been found and how these could have found their way to earth.

Well worth a look, the video can be found on Youtube.

Thank you to the OU Science Club for pointing me to this talk.