Another space post from me this week – seems those astronomers are hard at work at the moment.
This story comes via the European southern Observatory (ESO), where astronomers have found a Solar System 127 light years away which is the most similar to our own discovered to date. They have confirmed the presence of 5 planets that orbit the snappily-named star HD10180, and have evidence of two more.
They have been able to gather a conclusive set of data on the planets which includes their distance to the star and mass. They calculate mass by looking at how the light from the star is ‘wobbled’ by the effects of the planet’s gravity (presumably the larger the mass of the planet, the greater it’s gravitational pull on the light and the bigger the wobble). This technique is known as ‘Doppler spectroscopy’.
Aspects of this discovery can be used with classes ranging from KS3-KS5.
With KS3 and GCSE students you can pique their interest be asking them to consider if life might exist on any of these planets. HD10180 is very similar to our Sun and one of the planets discovered is only slightly bigger than Earth. Does this mean that aliens could have evolved on this planet, or is there more to it than that? The answer, of course is that there is a strict set of rules that have to be followed if life is ever going to get a foothold.
Scientists think that the planet has to have a surface temperature that will allow water, an essential solvent, to be in a liquid form. Life evolved on Earth because it exists at the right distance from the Sun for this to be possible – it is in the so-called ‘Goldilocks zone’.
I have expanded on this idea on this PowerPoint presentation. Students are introduced to the new Solar System and given facts about the Goldilocks zone, data about the Sun, HD10180 and planets in both our System and the newly discovered one. They are asked to use the data to work out if life could exist on any of the planets, and explain their reasoning. This could be done as a group activity as it lends itself well to discussion.
They should find out that most of the planets are larger than Earth so probably are gaseous. The planet that is around the same size is very close to the star, and as it is hotter than the Sun, this would mean that it is far too hot for life to exist on.
The planetary data can also be found on this excel spreadsheet which would be useful for GCSE classes who can use it to see trends and draw graphs. They can be asked to see if there is any correlation between distance from star and temperature or year length and then work out data on these for the newly-discovered planets’.
This story highlights the amazing discoveries that astronomers are making with technological advances in telescopes – for more examples please take a look at the other posts on astronomy.
Video on the newly discovered Solar System and how it was discovered
Information on Doppler Spectroscopy