Approach to Scanning Historic Glass Plates Yields an Astronomical Surprise. Technical details at
Precise Photometric Measurements from a 1903 Photographic Plate Using a Commercial Scanner.
Professional astrophotography used to be done on emulsion-coasted glass places. That was how astromical discoveries were made for nearly a
More than an estimated 2.4 million glass plates are out there in collections in North America alone. These were taken starting in
the 1890s right up until the 1970s, when CCD (Charged Couple Device) detectors started to come online for astronomy. Of these, only an
estimated 400,000 plates have been digitized to research quality
The team in this article has found a much cheaper way to proceed with this process, using
I went (via Zoom) to a great lecture last night. Serafina Nance spoke to the
The Calgary Centre of the Royal Astronomical Society of Canada on
Tracing the Lives, Deaths, and
Explosions of Massive Stars.
Supernovae are cosmic events of gigantic power. Their explosions can shine as bright as a galaxy, a pinprick of extraordinarily bright light in the night sky. What is less well-understood, however, is which stars reach the point of explosion and how they evolve to their deaths. Interestingly, their explosions provide astronomers with key tools to uncover fundamental aspects of our Universe. While we know that the Universe is expanding at an accelerated rate due to dark energy, the rate of the expansion of the Universe is not well-constrained. Supernovae provide us with independent ways to measure this expansion and work to resolve one of the most pivotal questions in astronomy: How fast is the Universe really expanding?
It’s confirmed. There is water on the Moon. OK,
what’s the big deal? Water is very common in the cosmos
and has been seen on the moon before. The
difference is that previously it had been been only in craters near the lunar south pole, perpetually in darkness. Now, as the updated NASA announcement said,
NASA’s SOFIA Discovers Water on Sunlit Surface of Moon,
which will be much more accessible to future explorers.
How significant this is remains to be seen, but it has provided Katie Mack with some
Last month I posted about a Possible Sign of Life on Venus, which
reported on Phosphine gas in the cloud decks of Venus.
Earlier this month I mentioned More about phosphine on Venus.
The story is not over yet.
A Question of Phosphine
Re-analysis of the 267-GHz ALMA observations of Venus: No statistically significant detection
. This team re-analyzed the same data used in the first Phosphine gas
paper, but came to the opposite conclusion. So it comes down to a very complicated question of statistical analysis.
Professor Coles also linked to A stringent upper limit of the PH3 abundance at
the cloud top of Venus by another team which included Jane Greaves, first author of Phosphine
gas in the cloud decks of Venus.
Inventing the Flat Earth: Columbus and Modern Historians, by Jeffrey Burton Russell, is the book for the day. Columbus did not show the world that the Earth was round. No educated European in 1492 believed that the Earth was flat. They all knew it was round. As all math geeks know, Eratosthenes of Cyrene had made a good calculation of the circumference of the Earth about 200 BCE.
Catholic church authorities did not say that the plan of Columbus to reach the orient by sailing westward was impossible because the Earth was flat. Their scholastic theology was based on the philosophy of Aristotle, who understood perfectly well that the Earth was round.
There are passages in the Bible that suggest a flat Earth, but almost all theologians of ancient and medieval times knew the evidence for a round Earth was overwhelming, and understood the Bible was not to be taken literally in this and similar cases.
The objection to the plans of Columbus was that, thanks to Eratosthenes, people had a good idea of the distance from the west coast of Europe to the east coast of China, and could easily calculate that no ship of the day could possibly carry enough supplies for the voyage.
Columbus, acting like a 21st century Republican, rejected the best science of the day and chose a smaller alternative value for the circumference that suited his purposes. He was just lucky that the Americas happened to be there. As a result their inhabitants were then horribly unlucky.
The story about Columbus and the flat Earth is a 19th century invention, not history.
Also posted on Facebook.
Following up on Possible Sign of Life on Venus. After that
announcement some scientists took another look at 1978 data from the
Pioneer Venus Multiprobe. At
the time nobody was specifically looking for phosphine, but a new analysis of the raw data supports the possibility that there is phospine in the
atmosphere of Venus. Details at Is Phosphine in the Mass Spectra from Venus’ Clouds?.
This has happened before in astronomy. After both Neptune and Pluto were discovered, astronomers looked at old records and found that their
predecessors had seen both bodies, but had not realized they were significant. In the case of Neptune one of those predecessors was
Yesterday I got an email from Cosmoquest about a science
press conference (“presser”) where a new discovery would be announced. With all the new distance-based
communication technology anybody could watch, rather than just those in a select room, however large. The
event was put on by the Royal Astronomical Society today. I watched it on the
Cosmoquest Twitch TV channel. I had never heard of Twitch TV before.
An international team of astronomers, led by Professor
Jane Greaves of Cardiff University,
today announced the discovery of a rare molecule – phosphine – in the clouds of Venus. On Earth, this gas is
only made industrially, or by microbes that thrive in oxygen-free environments.
The discovery was made by spectroscopy using two different radio telescopes. The significance of this is that the production of phospine
by purely chemical processes is very unlikely in the atmosphere of Venus. The team looked at every possible chemical reaction they
could think up, and failed to find any that could come close to producing the observed amount of phospine.