Monday, September 25, 2017

Astronomy, old and new

We're accustomed to news of exciting celestial discoveries made by American (meaning here: of the USA -- a useful clarification because of other topics to come) observatories and astronomers. It turns out, and I was surprised to read this, that American interest in astronomy goes way back.  

JQ Adams: astronomy geek
The Atlantic had a recent fascinating piece about that history. To wit -- archaic wording chosen with malice aforethought ;-)  -- "The Surprising Space Ambitions in Colonial America: Long before NASA, private individuals and communities banded together for the pursuit of geopolitical power and scientific discovery." The article starts in colonial times, but doesn't stop there. Who knew, for example, that John Quincy Adams was an advocate for astronomy? Good stuff. 

Speaking of NASA, they recently went far afield to study the Kuiper Belt Object next up on the itinerary for the amazing New Horizons probe. And the journey was worth it. The agency reports: "NASA’s New Horizons Team Strikes Gold in Argentina." The (metaphorical) gold? That the KBO toward which New Horizons is hurtling seems, in fact, to be two objects, in tight orbit around their common center of mass.

But why Argentina, you ask? For a very precisely aimed, precisely timed observation. To catch the little (less than 25 miles across) rock -- or, apparently, two rocks -- as, from a distance of 4.1 billion miles from Earth, it/they passed in front of a star. Talk about precision! More to come when New Horizons flies past 2014 MU69 on (mark your calendar) New Years Day, 2019 ....

But to me, the most exciting item of recent astronomy news is last week's announcement. Astronomers have long been puzzled by the origin of the highest-energy cosmic rays. And now, it seems, that after decades of uncertainty, we have a partial answer. Incidentally, the astronomical instrument (not an optical telescope) involved in this discovery was also located in Argentina.

For a fascinating read about cosmic rays, the reason it has been so difficult to ascertain their origins, and the latest discovery, see (from Physics World) "Ultra-high-energy cosmic rays have extra-galactic origins." But here's a key takeaway:

The measurements revealed that the arrival rate of ultra-high-energy cosmic rays is about 6% greater in one half of the sky. What is more, the excess lies about 120° away from the centre of the Milky Way – suggesting extra-galactic origins. After correcting its data for the expected bending of these cosmic rays by the magnetic fields of the Milky Way, the team says that the particles appear to be coming from directions in space that have a high density of nearby galaxies.

And while my novel in progress involves neither John Quincy Adams nor Argentina, I must nonetheless get back to it ...

No comments: