Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Rough Science Photo of the Rough Science cast
 Home | Death Valley | Scientists | Iain | Impact Diary - Day 3
Introduction
 
Series 4:
Death Valley
Rover
Communication
Spacesuit
Impact
Aerial Surveyor
Rocket
 
 
The Scientists
Director's Notes
Producer's Notes
Tune In
 
Series 1:
Mediterranean
Series 2:
Carriacou
Series 3:
New Zealand
 
About the Show
Discover More
Feedback
Site Map
 
spacer spacer spacer
Iain's Impact Diary Day 1 2 3

Day 3

Nope. No inspiration. Me, Kathy and Mike discuss the problem as soon as we get to the workshop. Mike is convinced that the up-scaling ought to work, and sets about mathematically justifying why it should. I’m just convinced that we don’t have anything better to throw at the problem. Kathy is busy being practical – laying out sheets of paper to graphically draw up the angles measured at the crater and work out its diameter. As we thought, the two measurements are quite different, one is 900 m and one is 1500 m. An average of 1200 m seems fine, but an error range of +/- 300 m looks pretty disappointing. For me and Kathy it’s OK – the crater wasn’t perfectly round so it won’t have a single diameter value anyway. I suspect Kate thinks we’re hedging our bets to hide sloppy field measurements, but Kathy stresses that it is just the way that scientists normally deal with natural variability and uncertainty. Kate nods, but the eyes say ‘sloppy, sloppy, sloppy…’.

Mike has convinced us that the linear plot of impact energy against crater size for the small measurements is worth extrapolating up to the size of our Meteor Crater. There’s loads of discussion about whether this might be a minimum estimate, given the explosive nature of the high velocity impacts. When Kate puts us on the spot, we go for a range. Now this is hedging our bets. The magical envelope reveals that Kathy’s spot on with diameter measurement – 1200 m. Amazingly – and I still can’t quite work out why – our estimate of the impact body being between 30 m and 100 m wide is also spot on; the scientific consensus says 50 m. It shouldn’t have worked, but it did. Exhilarated and drained, we find comfort in some beers and wait for night to fall.

Our bit is done, but the fun is just starting for Jonathan and Ellen. The telescope is working brilliantly, and we all can’t help but get involved as we get deeper into the night doing repeated measurements of the diameter of little Archimedes crater on the Moon. Under Ellen’s flickering lights, the effort pays off. Eventually, reluctantly, we pack up and head back - tired and happy.

 

< Previous

 

The edge of the crater
Scientist Diaries

All craters great and small - read the other team members' diaries as they attempt to measure the impact of impacts:

Ellen
Jonathan
Kathy
Mike