For such visitors especially, on we go to some intriguing news from two of the hardest among hard sciences: physics and astronomy ...
The new definition isn't radically different from the old one. For example, in our own solar system, the boundaries of the habitable zone have shifted from between 0.95 astronomical units (AU, or the distance between Earth and the sun) and 1.67 AU, to the new range of 0.99 AU to 1.7 AU.
So did we just make it, we Earthlings? Maybe. More likely, the models still need work, not least because:
The scientists cautioned that the habitable zone definition still does not take into account feedback effects from clouds, which will also affect a planet's habitability.
What else is new? Well, from Science World Report, "Scientists Uncover Mystery of Green Meteorite, State it is from Mercury." "Is" involves a bit of overstatement/oversimplification by the headline writer (what are the chances?) but a decent case can be made:
They found that the green space rock had a low magnetic intensity when compared to any other space rocks documented till date. On considering the data sent by NASA's Messenger spacecraft that is currently orbiting Mercury ...Mercury has low magnetism that matches the characteristics of NWA 7325.
Apart from this, they noted that the meteorite has low iron content and even Mercury's surface is very low in iron content. This confirms that the meteorite's parent body matches Mercury.
Gold on Earth formed in collision of exotic stars." The takeaway:
Gold is likely created as an afteraffect [sic] of a collision between two neutron stars. These collisions happen in our galaxy only about once every 100,000 years.
|Your heliopause at work|
Much in the sky changes over time. Consider this (sloppily written) headline from Yahoo! News: "Early humans probably saw a super-massive black hole in the night sky."
At the center of the Milky Way galaxy, about 25,000 lightyears away from our tiny little blue planet, lurks a slumbering monster: A super-massive black hole that, according to astronomer estimates, is about the size of four million suns.
One has to squint hard, IMO, to consider homo habilis "early humans." But how hard must you squint to to see a black hole?
|Flare by Milky Way's black hole|
Lest I leave any misimpression that physics and astronomy knows it all, check out this Live Science summary of "The 9 Biggest Unsolved Mysteries in Physics."