Water, Water Everywhere in the Galaxy #exoplanet #space #NASA

exoplanet populationsScientists have shown that water is likely to be a major component of those exoplanets (planets orbiting other stars) which are between two to four times the size of Earth…

Hopefully atmosphere observations in the future — of thick steam atmospheres — can support or refute the new findings.   Goldschmidt Conference

Many of these detected exoplanets are larger than Earth, but it sounds like a lot of that extra mass is water – up to 50% of the planet’s weight, while water on Earth is only 0.02%. Our watery blue world is a desert in comparison.

It makes me wonder… if our Sun had more heavy elements, would Earth be larger? Would it have captured more of the solar system’s water? Would you and I be fish?

We have earlier generations of stars to thank for any watery world including our own. Hydrogen is, of course, everywhere – the most abundant element starting from the Big Bang. But heavier elements owe their existance to fusion within stars and subsequent nova and supernova explosions. That includes oxygen. So water seems to be common in the galaxy.


Will We Find Extraterrestrial Life by 2040?

1906 edition

From the novel “War of the Worlds”

At space.com, a reader-survey shows 89% believe alien life exists elsewhere in the universe.  Seth Shostak of the SETI (Search for Extraterrestrial Intelligence) Institute thinks there’s a good chance we’ll find evidence of that in the next 25 years.  SETI Researchers have only listened for artificial signals from a few thousand star systems so far, but in 25 years they will have listened to a million systems.  “A million might be the right number to find something.”  Recent evidence of exoplanets helps fuel his optimism.  In addition to SETI’s listening programs, the search for life includes rovers on Mars and the possibility that space telescopes could detect oxygen or other signs of life in exoplanet atmospheres.

Ever since Frank Drake set up his famous speculative equation, the search for extraterrestrial life has been a quixotic project, always on the brink of going broke.  The search seems like such a long shot, yet it’s been too intriguing to abandon.

Would a confirmed, artificial signal – intelligence! – change anything?  Polls show many people already believe intelligent aliens have visited Earth; for example, a poll in 2012 found only 17% of Americans think aliens have definitely not visited Earth, and one in ten say they’ve seen a “UFO” (assumed to be of extraterrestrial origin).  People were even willing to speculate on which candidate in the last US Presidential election would handle an alien invasion better.  Maybe most people would greet news of an intelligent signal from far out in space with a shrug.  But it would send chills down my spine.