23 August 2012

Landing on another planet

I have a general fascination with everything science, so it should come as no surprise that I have been following the newest Mars expedition (dubbed Curiosity).  This newest rover landed on 5 August 2012.  I've seen and read quite a bit about the mission and the successful mission so far, but this newest video of the landing it BLEW ME AWAY.  Just to be clear, what you are watching is a human built craft landing on another planet.  Why this is not major headline news for more than the few minutes it got is still beyond me.


 

The first thing you see is the heat shield being jettisoned.  This shield protected the rover as it descended into the Martian atmosphere.  From the shield's departure, up until about 25 seconds, it appears as if the rover is simply hovering above the surface, but then things get interesting, as it becomes abundantly clear that the craft is actually descending toward the surface of Mars. The swaying is the result of the parachute that is further slowing the descent.  At about 28 seconds, as the parachute sways a bit more, we start to really notice how close we are getting to the surface.  At about 33 seconds we see plumes of dust at the rocket engines of the sky crane fire.  The sky crane held the rover during it's decent and also is the main way the rover ends up on the surface.  Once the rover is close to the ground, the crane lowers the rover down via several tethers all while hovering (this is where to dust plumes come from).  Soon after this you see one of Curiosity's wheels in the lower right and the rover touches down.  Again, truly amazing!

02 August 2012

Run! Bees! No....Wasps! Run faster!!!

Being an entomologist, I find most insects fascinating (I even think cockroaches are interesting), but the other day I had a run in with a not so fascinating set of insects.  I was doing some yard work and all of a sudden I got a very strong sense that I was under attack.  At first it felt as if I had placed my leg against a blow torch, followed very quickly with the same feeling on my hand.  This was enough to let me know to get out of where I was.  After heading to the house (OK, running for my life to the house) I placed ice on the affected areas, yelled a bit, then went looking for the source of my pain.  Turns out that I had waked into some ground nesting hymenoptera!

The hole (center) where the yellow jacket nest was located (about the size of a cantaloupe).
 At first I thought they were bees based on their size, but as I didn't see any stingers in my body my suspicion turned to wasps.  On closer (cautious) inspection, I determined these were yellow jackets (Vespula squamosa, the southern yellowjacket to be exact).  This species is common in the south and the majority construct hives underground. A fascinating fact is that they often usurp the nest of other species.

A worker V. squamosa (Biological Survey of Canada)
Normally I would leave well enough alone, but given how close the nest was to our outdoor living areas and that I have small children I knew the nest had to go. After first treating the nest with some "Wasp and Hornet" spray, it became obvious that stronger tactics were called for.  After some research, I determine a less toxic (and potentially more effective) approach was boiling water and oil.  However medieval this sounded, this actually makes a lot of sense.  First, the boiling water kills insects on contact, and second any that don't get hit can become coated in oil (in this case vegetable oil) which makes it difficult for them to fly (so they starve from lack of an ability to hunt).  After a couple of bucket fulls (at night as these guys don't fly after dark) I was able to eradicate the colony. 

I've since dug up the nest and pulled out quite a lot of the cells, which were all packed with larvae.  Had I not spotted the nest when I did (or blundered into it) it would likely have held many hundred adults by fall.  As it stood I would estimate there were several hundred already.

Some of the cells (white-ish ones are full of larvae) of the underground yellow jacket nest.