Slashdot Mirror
Hubble Discovers 'Planetary Graveyard' Around White Dwarf
astroengine send this interesting excerpt from Discovery: "The Hubble Space Telescope has discovered rocky remains of planetary material 'polluting' the atmospheres of two white dwarfs — a sign that these stars likely have (or had) planetary systems and that asteroids are currently being shredded by extreme tidal forces. Although white dwarfs with polluted atmospheres have been observed before, this is the first time evidence of planetary systems have been discovered in stars belonging to a relatively young cluster of stars. 'We have identified chemical evidence for the building blocks of rocky planets,' said Jay Farihi of the University of Cambridge in a Hubble news release. 'When these stars were born, they built planets, and there's a good chance that they currently retain some of them. The signs of rocky debris we are seeing are evidence of this — it is at least as rocky as the most primitive terrestrial bodies in our Solar System.'"
It says a relatively young cluster of stars. That doesn't mean that some members of the cluster aren't old enough to have gone nova. Also, larger hotter stars (than the Sun) don't stay in the main sequence nearly as long, so it's possible that some were just under the threshold to become neutron stars. There is no contradiction there.
that's probably the answer to the Fermi Paradox. For billions of years the earth had life, but only in the last few decades the technology that *might* have detected or made a signal to another star. In less than 350 million years, the earth will be too hot to support multicellular life due to expansion of the sun. what if every billion years or so an intelligent species arises within 10,000 light-years of any other place that has the same thing happen once at some random time over the life of the universe? they find themselves alone...
... we've come out of hyperspace into a meteor shower. Some kind of asteroid collision. It's not on any of the charts.
You put too much faith in our ability to detect other civilizations.
Who says they would be using technology noticeable to us?
Who says we'd even notice them with a 150 year delay between their actions and our ability to perceive them?
We know too little about how things work in space to draw any meaningful conclusions. Best to stop at, "Apparently, we saw nothing. Damn. Next section of the sky, please."
The universe is too big for us to be completely alone. The only question is: are they in range for us to find them before we or they go extinct?