jm + astronomy   8

An Orbit Map of the Solar System
This week’s map shows the orbits of more than 18000 asteroids in the solar system. This includes everything we know of that’s over 10km in diameter - about 10000 asteroids - as well as 8000 randomized objects of unknown size. This map shows each asteroid at its exact position on New Years’ Eve 1999. All of the data for this map is shared by NASA and open to the public.


Really lovely stuff!
astronomy  dataviz  map  space  visualization  asteroids  planets  posters  moons  solar-system 
14 days ago by jm
_First M87 Event Horizon Telescope Results. III. Data Processing and Calibration_
'We present the calibration and reduction of Event Horizon Telescope (EHT) 1.3 mm radio wavelength observations of the supermassive black hole candidate at the center of the radio galaxy M87 and the quasar 3C 279, taken during the 2017 April 5–11 observing campaign. These global very long baseline interferometric observations include for the first time the highly sensitive Atacama Large Millimeter/submillimeter Array (ALMA); reaching an angular resolution of 25 μas, with characteristic sensitivity limits of ∼1 mJy on baselines to ALMA and ∼10 mJy on other baselines. The observations present challenges for existing data processing tools, arising from the rapid atmospheric phase fluctuations, wide recording bandwidth, and highly heterogeneous array. In response, we developed three independent pipelines for phase calibration and fringe detection, each tailored to the specific needs of the EHT. The final data products include calibrated total intensity amplitude and phase information. They are validated through a series of quality assurance tests that show consistency across pipelines and set limits on baseline systematic errors of 2% in amplitude and 1° in phase. The M87 data reveal the presence of two nulls in correlated flux density at ∼3.4 and ∼8.3 Gλ and temporal evolution in closure quantities, indicating intrinsic variability of compact structure on a timescale of days, or several light-crossing times for a few billion solar-mass black hole. These measurements provide the first opportunity to image horizon-scale structure in M87.'
papers  data  big-data  telescopes  eht  black-holes  astronomy 
10 weeks ago by jm
81 Megapixel image of the moon
I took nearly 50,000 images of the night sky to make an 81 Megapixel image of Tuesday's moon. Uncompressed image linked in the comments. [OC]


via Elliot
via:elliot  art  moon  astronomy  photography  hd 
february 2019 by jm
The 26,000-Year Astronomical Monument Hidden in Plain Sight at the Hoover Dam
This is amazing! I wish I'd noticed it when I visited Hoover Dam.
The center of the circle traced by the axial precession is actually the massive flag pole in the center of the plaza. This axial circle is prominently marked around the pole, and the angle of Polaris was depicted as precisely as possible to show where it would have been on the date of the dam’s opening. Hansen used the rest of the plaza floor to show the location of the planets visible that evening, and many of the bright stars that appear in the night sky at that location.

By combining planet locations with the angle of precession, we are able to pinpoint the time of the dam’s completion down to within a day. We are now designing a similar system — though with moving parts — in the dials of the 10,000 Year Clock. It is likely that at least major portions of the Hoover Dam will still be in place hundreds of thousands of years from now. Hopefully the Clock will still be ticking and Hansen’s terrazzo floor will still be there, even if it continues to baffle visitors.


(Via Tony Finch)
hoover-dam  history  precession  astronomy  long-now  polaris  vega  thuban  stars  clocks 
january 2019 by jm
The power of role models
At dinner I asked some of the women to speak to me about this, how astronomy became so (relatively) egalitarian. And one topic became clear: role models. Astronomy has a long history of women active in the field, going all the way back to Caroline Herschel in the early 19th century. Women have made huge contributions to the field. Dava Sobel just wrote a book about the women who laid the foundations for the discovery of the expansion of the universe. Just a couple of weeks ago, papers ran obituaries of Vera Rubin, the remarkable observational astronomer who discovered the evidence for dark matter. I could mention Jocelyn Bell, whose discovery of pulsars got her advisor a Nobel (sic). The most famous astronomer I met growing up was Helen Hogg, the (adopted) Canadian astronomer at David Dunlap Observatory outside Toronto, who also did a fair bit of what we now call outreach.

The women at the meeting spoke of this, a history of women contributing, of role models to look up to, of proof that women can make major contributions to the field.

What can computing learn from this? It seems we're doing it wrong. The best way to improve the representation of women in the field is not to recruit them, important though that is, but to promote them. To create role models. To push them into positions of influence.
software  women  feminism  role-models  gender-balance  egalitarianism  astronomy  computing  rob-pike 
february 2017 by jm
the "Unknown Pleasures" cover, emulated in Mathematica
In July 1967, astronomers at the Cavendish Laboratory in Cambridge, observed an unidentified radio signal from interstellar space, which flashed periodically every 1.33730 seconds. This object flashed with such regularity that it was accurate enough to be used as a clock and only be off by one part in a hundred million.

It was eventually determined that this was the first discovery of a pulsar, CP-1919.  This is an object that has about the same mass as the Sun, but is the size of the San Francisco Bay at its widest (~20 kilometers) that is rotating so fast that its emitting a beam of light towards Earth like a strobing light house! Pulsars are neutron stars that are formed from the remnants of a massive star when it experiences stellar death.

A hand drawn graph plotted in the style of a waterfall plot, in the Cambridge Encyclopedia of Astronomy, later became renown for its use on the cover of the album "Unknown Pleasures"  by 1970s English band Joy Division.


The entire blog at http://intothecontinuum.tumblr.com/ is pretty great. Lots of nice mathematical animated GIFs, accompanied by Mathematica source and related ponderings.
maths  gifs  animation  art  unknown-pleasures  mathematica  cp-1919  pulsars  astronomy  joy-division  waterfall-plots  cambridge  blogs 
december 2014 by jm
Sweden Solar System
the world's largest permanent scale model of the Solar System. The Sun is represented by the Ericsson Globe in Stockholm, the largest hemispherical building in the world. The inner planets can also be found in Stockholm but the outer planets are situated northward in other cities along the Baltic Sea. The system was started by Nils Brenning and Gösta Gahm and is on the scale of 1:20 million.


(via JK)
scale  models  solar-system  astronomy  sun  sweden  science  cool  via:jk 
august 2014 by jm

Copy this bookmark:



description:


tags: