May 2024
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Chasing Galileo - 17/18-day old moon

Eighteen-day moon

The moon rises later each evening now. That means a late night for sketchers. Luckily my small 70mm Televue Ranger on a telepod mount requires no setup. I keep it permanently set up in the garage.

The features I’ve sketched on the 18-day moon begin with sunset on Mare Crisium – on the terminator [...]

Chasing Galileo: Jupiter and Neptune in the same field of view

Galileo noted a fixt star (at left), now known to be Neptune on this sketch from December 28, 1612

Skymap Pro chart of Jupiter and Neptune (the square at left), December 28, 1612

My sketch of Neptune with Jupiter and the Galilean moons

Galileo made the first recorded observation of Neptune in 1612 when Neptune [...]

Chasing Galileo - fourteen-day moon

fourteen-day (full) moon

The full moon rises as the sun sets on the 14th day of the lunar month. A small telescope, such as the 70mm f.8.7 Televue Ranger I’m using for this series of sketches is a perfect instrument for full moon viewing. So are binoculars. The moon is [...]

Chasing Galileo – Head of Orion cluster

Galileo’s Head of Orion cluster

Jane’s Head of Orion cluster

Astrophoto of Orion Head cluster by Morris Jones

Map of the constellation Orion

Galileo looked at the fuzzy patch surrounding the head of Orion through a telescope, and resolved many starts not previously known. He called it Nebulosa Orionis.

Look between the shoulder stars Betelgeuse and [...]

Chasing Galileo – Jupiter and the four Galilean satellites

Galileo’s drawing

my drawing

my sketch of Jupiter’s rotation

Galileo published his observations in Sidereus Nuncius in March 1610: “On the 7th day of January in the present year, 1610, in the first hour of the following night, when I was viewing the constellations of the heavons through a telescope, the planet Jupiter [...]

Chasing Galileo – sketches of the nine-day moon

nine-day moon

Lunar creature features

Rabbit on the full moon

Night owls can enjoy the nine-day moon – it’s up all night long. In my sketch, the magnificent crater Copernicus is visible on the sunlit side of the terminator – on the right side of the lunar center. It looks so insignificant right now, but [...]

Chasing Galileo – sketches of the 3-day moon

three-day old waxing moon

This year, my observing project is to recreate as many of Galileo’s original telescopic observations as I can. I’ll be using my smallest telescope, a 70mm refractor, and making my sketches using a 25mm eyepiece for a magnification of 19x. Each of my lunar sketch pages will each show three [...]

Chasing Galileo – sunspots

Galileo's sunspots

My sunspots

In the summer of 1612, Galileo sketched a series of sunspots which were published in Istoria e Dimostrazioni Intorno Alle Macchie Solari e Loro Accidenti Rome, (History and Demonstrations Concerning Sunspots and their Properties), in 1613. Galileo corresponded with other scientists and artists who also were sketching the [...]

Chasing Galileo: the Trapezium

Galileo’s Trapezium

My Trapezium sketches

Galileo’s observed the Trapezium stars in the sword of Orion on February 4, 1617. He labeled the three stars “c”, “g”, and “i”. These stars are known now as the “D”, “C” and “A” components of Theta 1 Orionis, or 41 Orionis. He did not see the fainter [...]

Chasing Galileo: sketches through a small refractor

Galileo telescope replica and my TV Ranger

Galileo's 1609 telescope

There were separate housings at either end for the objective and the eyepiece

When I started thinking about how to integrate International Year of Astronomy into my 2009 What’s Up podcasts I naturally focused on Galileo’s first observations through a telescope 400 years [...]