The PHASTT Network

I have the good fortune of being in Spain right now to collimate the TFRM Baker-Nunn camera. Some work had been done recently to replace a failed shutter and, as is normally the case, the telescope and camera were not optically aligned after reassembly. Anyway, with a new shutter installed, collimation proceeded with no problems. The TFRM is now operational again and should be robotically observing transient events like exoplanets in the near future!

But that’s not really what this post is about. On the way up the mountain this morning we stopped at the proposed site for the PHASTT-1 characterization telescopes. The site is about 3/4 of the way up the mountain on a broad plateau (as you can seen in the above image). The actual observatory building will be the old farmhouse that is just visible below the centre of the image. The roll-off roofs covering the scopes (there will be more than 1 here) will be on the side nearest the camera. Anyway, it’s a great site with dark skies from which we expect to be able to do some interesting asteroid characterization work. This sort of information is vital for discoveries of small objects on an imminent impact course as it will tell us something about what they’re made off. Knowing that, will tell us whether a small impactor will innocently burn up in the atmosphere or make it to the ground and cause a lot of damage. A 50 m iron object, for example will probably make it to the ground with a large part of its cosmic velocity. The result will be a rather large hole (about 1.5 km across). A 50 m rocky object, on the other hand, is more likely to break into fragments a few km above the ground. There will most likely a large number of big fragments striking the ground but they will probably do less damage (puncturing roofs instead of obliterating entire neighbourhoods). It’s like comparing the effects of a shotgun slug to shot. And, although it may sound preferable to be in the path of the rocky fragments (‘shot’) instead of the competent iron (‘slug’), it’s a moot point as we’ve ignored the effects of the shock wave. Even at 5 km from the impact point the shock wave winds will be on the order of 800 km/h. Go out to 15 km from the point of impact and they’ll drop to 150 km/h. Which is probably still enough to take you for a ride. Please help us spread the work by sharing/liking this post!

On a lighter note, below is another image of the PHASTT-1 location with Montsec in the background. Click on the image to make it bigger and see if you can see the site (lower left) and the paragliders in the air!

#Asteroid #ImpactCrater