Tuesday, September 6, 2016

The final frontier

Stamp out mediocrity ;-)
2016 being the 50th anniversary year for Star Trek, you can guess what inspired today's subject line. But this post is about the actual frontier, about astronomy news, not fiction.

Based upon data collected by the Dawn space probe, NASA scientists have a new understanding of the dwarf planet, aka the largest asteroid, Ceres: "Ceres interior structure gives hints of early life." (That's "life" as in active geological processes, not as in protoplasm wiggling about.) Ceres is a slushy world, not rocky like Vesta, Dawn's previous observational target. Which makes all the more intriguing that "NASA just found an ice volcano on Ceres that's half the size of Everest."

Speaking of rocky worlds ... unless you've been off the grid on this one, you've likely seen that "Rocky planet found in habitable zone around Sun's nearest neighbor." Wow! Discovering Proxima Centauri b more than makes up for the debunking of the previously suspected planet around (the just slightly more distant star) Alpha Centauri B. (*)

(*) Alpha Centauri B is the smaller of two closely co-orbiting stars that together comprise the binary star Alpha Centauri. Proxima Centauri b is a planet, the first object discovered associated with its star. Hence one cosmic object gets a "B" and the other rates merely a "b." (The suspected planet once thought to be orbiting Alpha Centauri B was thus called Alpha Centauri Bb.)

Artist conception of Proxima Centauri b

 Want to visit Proxima Centauri b, or at least get a look at it? (Astronomers can sense that planet's existence, and approximate its orbit and size, through its slight gravitational influence on its star; b [if I may be so familiar] despite its relative nearness, has not been -- cannot yet be -- imaged.) Of course you do. Then check out "How can we get to Proxima Centauri b?" Just don't expect to get there anytime soon ...

 Moving out a bit, from about 4 light-years to more like 95 ... a much-reported prospect of an "alien" radio signal has been quickly discounted. See "Turns out the signal astronomers saw was “strong” because it came from Earth."

Speaking of aliens (not!), and somewhat more distant still, it turns out Tabby's Star isn't unique in exhibiting a highly variable light curve. Could two neighboring interstellar high-tech civilizations be concurrently building Dyson spheres? Seems unlikely, doesn't it. Check out the new, protoplanetary-disk theory for what may explain such highly variable light output: "Researchers just found a second 'Dyson Sphere' star: But still no aliens."

We'll wrap up today with a final -- and, IMO, the most mind-blowing -- report. Astronomers have discovered a new galaxy that's a mere 300 million light-years from Earth. Astronomers routinely study galaxies many billion light-years remote. But those emit decent amounts of light. See "Dragonfly 44 Galaxy Is Made Up Of 99.99 Percent Dark Matter: How This Discovery Changes Everything."(For more about all we don't know about dark matter, see my recent post, "A physics extravaganza."

The new find ... looks nothing like this!
It pays to look up occasionally from messy affairs on our own world ...

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