The chairman welcomed members and guests to the October meeting and commented on the result of a recent feedback survey on how the club was meeting its expectations; news items and sky-notes were well received by respondents and lectures were reckoned to be set at a level “about right” for most of the audience.
Sky Notes for October
Mid October the skies are astronomically dark at 8:15. A general roundup was made of the many objects to be seen in the October sky. Lots going on!
If the observing evening was not organised this weekend then it may be prudent to wait until around the 31st October when the skies were dark at 6:45 pm. Members were again reminded to check the web page, Observing Evening, on this site and not to travel to an observing evening unless the red text had changed to blue!
This exoplanet detecting satellite is now fully operational and monitors the change in luminosity of nearby stars that may indicate planets. Proving to be very capable data is now being received from Tess that is characteristic of planets passing in front of stars. Further updates to follow.
David Glass explained the intricacies of this fascinating Japanese project that involves instrumentation landing on the asteroid termed Ryuga. Of interest to early solar system research, this operation will aim to capture material from the asteroid and return it to Earth for further analysis. For a detailed but (mostly) understandable description, see: Hayabusa 2
A recent photograph of Opportunity on Mars that has now lost contact with its project team.
Analysed data from ESA`s Gaia surveyor has narrowed down where the interstellar traveller Oumuamua may have come from. The database combined with trajectory science has narrowed the source of Oumuamua to 4 stars within our galaxy.
Bright objects on Ceres have now been associated with mud deposits. New research has indicated water and rock have erupted and may be responsible for the bright surface detail on the surface of Ceres.
Guest speaker: Prof. Lionel Wilson of Lancaster University who spoke on recent ideas on the volcanic history of the Moon
An interesting talk on the ancient volcanic lava flows on the moon and how there may be lessons to learn with Earth`s volcanism both in the past and in the future!
IMP`s and RMDS were discussed at length. These are Irregular Mare Patches and Ring Moat Dome structures. 70 IMPs have been discovered 19 of which are around obvious vents. The recent research indicates there may be consequences for the Earth because we may be due a major basalt eruption on a scale of an extinction event.
The far side of the moon has a crust that is 60% thicker than the nearside that faces Earth. Most volcanism occurred on the nearside face of the moon and occurred more than 1 billion years ago.
Eruptions on the moon form dome shapes because there is no atmosphere. Sinuous rilles (look like rivers) form due to the thermomechanical erosion of the surface of the moon and can extend for several kilometres; the turbidity of the lava flow and a high lava discharge rate are key features in their formation.
Ring-Moat Dome Structures (RMDS) are a newly discovered feature on the lunar surface; low domes surrounded by a shallow cavity or moat. Large-scale lava flows are now thought to have occurred on timescales much more rapid than previously thought.
Theoretical models were discussed regarding their construction and magmatic foams were highlighted as a possible precursor. Over 2000 of these structures (RMDS) have been identified.
For further details see the recent Geophysical Research Letter: – Newly Discovered Ring-Moat Dome Structures in the Lunar Maria