The Search For Planet 9
Main speaker - Mike Brown
Professor of planetary astronomy at the California Institute of Technology
Back in 1930, Pluto was discovered by Clyde Tombaugh and it became the solar system’s 9th planet.
However in 2005, Mike Brown led a team that discovered the similarly-sized Eris. With this and several other objects discovered out beyond Neptune, the question was raised as to whether some of these should also be recognised as planets.
The result was a vote at the 2006 General Assembly of the International Astronomical Union on a definition of a planet. This led to Pluto being re-designated as a Dwarf Planet, bringing the solar system down to 8 planets.
In January 2016, Brown and fellow Caltech astronomer, Konstantin Batygin, proposed the existence of Planet Nine as a major planet between the size of Earth and Neptune.
Having led the teams responsible for the discoveries of so many distant objects, including Eris, Haumea, Makemake and Quaoar, plus others that should be regarded as Dwarf Planets, such as Sedna, Orcus, Gonggong, Mani and Salacia, no-one can deny that Mike Brown is the most appropriate person to cover the subject of the search for Planet 9.
We are therefore delighted to have him as a speaker on this subject. As Mike is based in California, a start time of 5pm UTC will be 9am PDT for him.
Jerry Stone will give an introductory presentation of about 20 minutes. This will cover the ancient views of the night sky, with the naked-eye planets, then the discoveries of Uranus, Neptune and Pluto, before moving on to briefly mention recent discoveries and the IAU's actions to deal with the increasing number of objects being found.
Mike will then bring us up to date with the possibly of Planet 9.
You may like to submit questions in advance by writing to Jerry at meetings@fedastro.org.uk by 18 October, so that they can be sorted and collated.
