Bad news

Observations of 1.6 million quasars (incredibly powerful active galaxies millions and billions of light years away) allow ultra precise positioning and pointing of space probes.

www.sciencemag.org/news/2020/11/precise-maps-millions-bright-quasars-show-our-place-cosmos-never

Quite a long read, but an interesting story....

"On a Friday at the end of 2018, the top brass of a NASA deep space mission convened for a tense meeting. Hour by hour the New Horizons probe was hurtling toward a New Year’s Day rendezvous with Arrokoth, an ancient, icy rock at the edge of the Solar System way out beyond the orbit of Pluto, the space probe's previous destination a couple of years before. The team had one last chance to send instructions for pointing the probe’s cameras. Success would ensure in-frame pictures of Arrokoth, and the clues it held for how the planets formed. Failure would mean expensive pictures of an empty void.

But the mission managers who gathered at New Horizons headquarters in suburban Maryland realized they had a “massive problem,” says Marc Buie, a team member and planetary scientist at the Southwest Research Institute in Boulder, Colorado. Something was off in images already beamed back. Either the flying spacecraft or the orbiting rock was a teensy bit lost in a universe where nothing is nailed down.

The team debated what to fix. Some thought the probe’s position, calculated from Earth-based measurements, was correct, in which case Arrokoth was in an unexpected place. But Buie believed the rock was right where it should be, which suggested thrusters had nudged the spacecraft itself a hair off course.

Buie was confident because he was tracking Arrokoth’s position relative to an ultraprecise map of far-off beacons called quasars: cosmic lighthouses generated by black holes in distant galactic centers. But the map was largely untested, having just been released by a European Space Agency star-mapping satellite called Gaia. It was the basis of a brand-new celestial reference frame, a fixed, imaginary grid against which everything else moves, akin to lines of latitude and longitude on Earth. And Buie was gambling the Arrokoth flyby on that new grid.

For the past few decades, astronomers have based their celestial grid on radio observations of several thousand quasars. These radio beacons not only guide the pointing of telescopes, but they are also the bedrock of the reference frame for the spinning, bucking Earth. Without them, GPS devices would lose their accuracy and many ultraprecise studies of processes such as plate tectonics and climate change would be impossible. But observations of these beacons are costly and rely on radio telescopes.

By 2018, when New Horizons was approaching Arrokoth, Gaia had produced its own version of a reference frame, based on half a million quasars seen in the visible wavelengths most astronomers use, not radio. Buie persuaded the New Horizons team to trust the new framework. A correction based on the Gaia positions went up to the probe.

The team got it right: When the closest flyby images came back, Arrokoth was framed perfectly. “None of that would have happened if we hadn’t had the Gaia catalog,” Buie says. “It’s a fundamental rewriting of how we do positional astronomy.”

OMG, we're doomed.

Suddenly we're 2,000 light years closer to the voraciously hungry supermassive black hole at the centre of our galaxy.

www.universetoday.com/148997/a-new-measurement-puts-the-sun-2000-light-years-closer-to-the-center-of-the-milky-way/

Actually, it's just a better understanding of the Sun's stable orbit in the ever-spinning Milky Way.

Understanding the shape and dynamics of our own galaxy is vastly more difficult than learning about other galaxies, far far away. It's the ultimate "can't see the woods for the trees".
The new research indicates that rather than being 27,700 light years from Galactic Centre we're actually only 25,800 light years away.
Still out in the boondocks, though!


Here's a schematic of the new measurements, and the deduced shape of the complexities of the spiral galaxy in which we live, and our location in it. 

The end of the giant Arecibo radio telescope today

"The iconic Arecibo Observatory in Puerto Rico has been destroyed after a 900 tonne metal platform suspended above the telescope collapsed around 8 a.m. local time today."

physicsworld.com/a/arecibo-observatory-destroyed-as-metal-platform-collapses-onto-the-iconic-telescope/

The best yet photographic survey of our nearest galactic neighbours, the Large and Small Magellanic Clouds. (Sadly only visible from the southern hemisphere). These are two dwarf galaxies that are orbiting and interacting with our own Milky Way galaxy.

A rather good vid of the new observations in this link.
phys.org/news/2020-12-dark-energy-camera-snaps-deepest.html

Odd indeed. I love that the more resolving our astronomical equipment becomes, the more weird stuff we discover.

Video of the collapse of the Aricebo radio telescope.
It's quite impressive!

www.businessinsider.com/video-arecibo-telescope-puerto-rico-collapse-2020-12

There's a cool planetary alignment due around the 20th/21st. Might wanna get your telescopes out for that

Yes, 'Starship' is a bit hopeful!