February 24, 2018

02.04.11: Stalking an Impact.

Click image to see animation…(Credit: Stefano Sposetti/Marco Iten/Geological Lunar Researches Group).

Take a look at the image above. It may not be one of the most colorful we’ve ever run, but it shows something dramatic; a possible impact on the limb of the Moon. On February 11 of this year, Stefano Sposetti and Marco Iten of Gnosca Observatory Switzerland used a Borg 125 ED refractor and a high speed video camera along with a similar setup attached to a Celestron 11 at a separate location to record the flash on the nighttime side of the then just past 1st Quarter Moon. [Read more...]

Review: Seeing & Believing by Richard Panek

Much has been said over the years about how the invention of the telescope has changed the science of astronomy, but how has it changed us and our view of our place in the scheme of things? Enter Seeing & Believing: How the Telescope Opened Our Eyes and Minds to the Heavens by Richard Panek. I discovered this amazing little book in our local library from a reader tip, and found it a thoroughly interesting and engaging read.

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Astro-Challenge: Spot Neptune in its Original Discovery Position!

In this week’s astro-event, we challenge you, the sky watching public, to view the planet Neptune as it was first seen on the night of its discovery on September 23, 1846. On that evening, astronomer Johann Galle turned the Berlin Observatories’ 9-inch refractor on a position given to him by French mathematician Urbain Jean-Joseph Le Verrier, and the solar system hasn’t been the same since. The discovery of Neptune was a triumph for predictive mathematics and a good test of Newtonian mechanics in a celestial format.

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Review: The Telescope by Geoff Anderson.

Few inventions are as near and dear to our hearts as that of the telescope. Before its invention, astronomy was scarcely better than its pseudo-science companion of astrology in its knowledge of predicting the universe as it truly is. In this week’s review, we’ll look at The Telescope by Geoff Anderson out from Princeton Press as it traces the history of this noble instrument, its origins, the theory of optics, and our present day understandings and the exciting realm of telescopes yet to come.Out from Princeton University Press!

Think you know everything about telescopes? The Telescope will take you through designs from classical refractors to Coudè focus complexities. This would serve as a good 101 for anyone thinking of building or even purchasing a telescope, as a lot of the optical basics are discussed. You can even skip through chapters, and the author even suggests that you don’t have to struggle through chapters on interferometry (but of course we did!) unless you really want to.

The study of how early astronomers actually functioned always personally fascinates me. We all know the discoveries of Galileo, but just how did he make those refractors in a renaissance era work shop? The absurdity of some of the focal lengths used was astounding; this was required to overcome the fringes on chromatic aberration until 2-element crown and flint objectives were perfected. And don’t forget, they had to handcraft eye-pieces, as well. Just how many modern day telescope makers do that?

The evolution of site selection and observatory construction is also discussed; it’s a generally underappreciated fact that seeing and turbulence makes up about 90% of your ultimate astronomical success. Early telescope users were content to perch their tubes on the ledge of a study window. It’s only been in the last century or so that site selection prior to observatory construction has really matured. In the modern era, the effects of encroaching light pollution also has to be accounted for. Telescopes have gone from backyard curiosities to behemoths of national significance.

The modern era of scopes is also traced, from the Hale and Keck telescopes to the Hubble Space Telescope, which is appropriately given its own chapter. The chapter “When Good Telescopes go Bad” is particularly illuminating, as it demonstrates the engineering challenges that seem to plague every great instrument. It’s been said that it’s never truly a great scientific or engineering breakthrough until someone has had a nervous breakdown, and building cutting edge telescopes is certainly a case in point.  The author also addresses the innovative methods the have been developed to squeeze as much information as possible out of every photon of light. Just think, we can know speed, direction, composition and more just from “tasting” starlight. This was first developed by the breakthrough of spectroscopy, and further refinements such as interferometry and adaptive optics have pushed the envelope even further. adaptive optics itself used to be classified, as it was used primarily to peek at Russian payloads in low-Earth orbit. Some of this technology is truly amazing; for example, did you know it’s possible to “record” a conversation in a room just by measuring via laser the vibrations imparted on the windows? To this effect, the Oval Office actually employs “shakers” on its outer panes, probably not much different than the vibrate mode on your cell phone.

A look at the key discoveries of the telescope and some of the more bizarre and unusual telescopes is also given treatment; two of our favorite are the use of liquid metal (mercury in a precisely rotated dish!) telescopes, and of course, the Laser Interferometry Gravitational wave Observatory, a “telescope” used to hunt for gravity waves.

And that’s just the beginning. The future of telescopes will see the James Webb Space Telescope, mega observatories such as the Thirty Meter Telescope (TMT) and the 100-meter OverWhelmingly large telescope (OWL) and perhaps even more exotic arrays such as the Terrestrial Planet Finder or a large crater-based instrument on the Lunar far-side.

Do give the Telescope a look if you are thinking of buying, building, or just have a passion for these grand old instruments. Telescopes represent the cutting edge of human technology, and never fail to inspire. And as astronomers, observatories are the closest thing to a cathedral to the stars that we possess!

Remembering the Super Flare of 1859.

This coming Tuesday marks the 150th anniversary of a unique astronomical event that has repercussions even today. On the morning of September 1st, 1859, Astronomer Richard Carrington found his routine of carefully drawing and recording the transit times of sunspot groups disrupted by an odd phenomenon emerging on the face of the Sun. The day dawned unusually sunny over his private observatory in Redhill, England, and 33 year old Carrington had taken to his usual daily task of sketching sunspot groups projected onto a screen in a darkened room. The scope used was a 2-meter long brass refractor, (scopes were often measured by focal length instead of aperture in those days) and it yielded an 11-inch diameter projected image of the Sun. the Sun itself had been extremely active most of the year, and there was plenty to draw.

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Starting into Astronomy: To Buy (Or not Buy) a Telescope?

   One of the questions I most frequently recieve is “what kind of telescope should I buy as a beginner or for a child?”  Certainly there is a lot of pitfalls to avoid, and very few hands on resources to test drive a potential new scope.  [Read more...]