Wednesday, March 06, 2013

ALIEN LIFE FOUND ON EARTH?

Can planets with extreme climates support complex life? Maybe. This little creature, only a millimeter long, is a tardigrade, also called a "Water Bear." It can live for decades without food or water, can survive temperatures ranging from near absolute zero to well above the boiling point of water, and can survive high pressure and very dangerous
radiation.


It's (above) so different than other life forms on Earth, that it's tempting to speculate that it doesn't come from here, but there's no evidence of that. It does have DNA just like we do, but it's more efficient at repairing it.

Russia attempted to salt Phobos with these things, but the rocket failed so Phobos was spared.



That's (above) an artist's rendering of our own galaxy. It's a spiral emanating from a bar. Probably the odd shape is the outcome of a collision with another galaxy. It must have happened a long time ago because it takes a while for merged galaxies to find a stable shape.

Just how old is our galaxy? Believe it or not, our own is one of the oldest galaxies we know of. It began to form long ago, shortly after galaxies first came into existence.



Question: which is older, the Earth or the Sun? Answer: the Earth. The proto-Earth formed when the Sun was still a hot ball of gas, before it ignited and became a star.


 When the Sun ignited it pushed out a giant shock wave that sent most of the smaller rocks and dust out past the present edge of the planetary Solar System. They settled into  a disk of remote asteroids called the Kuiper Belt. I think the Ort Cloud might have had a different origin.



Probably I'm the only person on this site who failed to see this footage when it was new. It's the meteorite that recently fell in the Urals. Although the rock is thought to have been no bigger than a car, the impact energy is estimated to have been that of several Hiroshimas.

4 comments:

Aaron said...

Wow those are some neat little critters!

Roberto Severino said...

The actual name for the water bear would the tardigrade. Wikipedia also says you can call them moss piglets. I remember watching a documentary where those animals were featured, probably somewhere like The Science Channel. Great stuff.

pappy d said...

It'd make a great Halloween costume!

Robert Schaad said...

They look like vacuum cleaner bags with legs.