Last Chance to Observe Sunlit SMART-1 Impact Site before Impact
18 August 2006With the Moon now in its last crescent phase, visible after midnight and before sunset, the next nights offer the last chance to make ground-based observations of the SMART-1 impact site in sunlight.
In the nights of 18 and 19 August 2006, observations can be used for reconnaissance maps of the surface features, possibly in various colours.
On 20 August the terminator will be near Lacus Excellentiae, the region where SMART-1 is scheduled to impact the surface on 3 September. This is a perfect opportunity to map the long shadows over the still uncertain topography of the area. Amateur and professional astronomers are encouraged to image the areas at these dates for a detailed analysis of the area's relieves.
On 21 August the terminator will have passed Lacus Excellentiae and the region will no longer receive direct sunlight, but it will be well illuminated by Earthshine, with Earth presenting a gibbous face. Ground observations on this date can be a good rehearsal to recognise the potential sites of impact in Earthshine, in preparation for observations on the night of impact itself.
On 4 September, the SMART-1 impact site will move into direct sunlight again as the terminator crosses Lacus Excellentiae. This allows searching for the SMART-1 ejecta blanket by comparing new observations with those made prior to impact.