Phases of Venus

June 4th, 2018

The skies this spring are graced by the closest and yet perhaps the most enigmatic object beside our moon. The planet Venus has been sparkling in the western sky now for weeks. Our nearest planet has a number of mysteries associated with it - it’s cloud cover and it’s sulfuric acid atmosphere and a surface corroded past any terrestrial warranty of any kind. But perhaps Venus’ most wondrous mystery is the characteristic of the bright planet right in front of our very eyes - it’s phases.

We marvel now at this jewel of the evening sky (sometimes in the morning). For centuries, people of planet Earth have worshiped Venus as a Goddess in her many guises.  But until 1610, when Galileo peered through his modest telescope, the entire human race was ignorant of her changing face as she drifts around the Sun. When we look closely at our sister planet, with a little bit of magnification, we get to see that Venus goes through phases, very much like our moon. This is what Galileo saw in 1610 and the result of his observations essentially clinched the argument for the Copernican Heliocentric theory.

For us mere mortals, we can simply aim a small telescope up at Venus and enjoy it for ourselves. As of this writing, Venus is almost 80 percent full or basically still a gibbous shape. Venus reaches half phase in mid August. After then, as the planet comes around in its orbit over the next few weeks, that shape will steadily work it’s way into a crescent shape that grows ever thinner. By late September, this crescent gets very thin and by late October, the planet is too close to the Sun for safe observation. Shortly after this time, she becomes the “morning star” once again, emerging ahead of the sun in the pre-dawn morning light.

Take some time to get to know our sister in the sky. Check these links below for more details on the phases of Venus. Wikipedia Venus & Wikipedia Galileo

Moon tools Pt 1 (The Intro)

December 16th, 2017

I’m a tool kinda guy. You know .. Swiss Army knife, a good flashlight, some vice grips, and, of course, a good astronomy app. Web based tools and apps for astronomy and stargazing are really the good stuff. This series is going to delve into various tools I’ve found on the web that help understand our moon better. This is part one, which, implies additional parts, theoretically. So, we’ll see how my research goes and how many tools we find.

Bar none, my favorite web site is still Sky View Cafe (SVC). You can see some of my other posts with details on the features, but my main tip here is to set your SVC startup view to be the calendar instead of the default Sky view. This is easy to do using the “More…” button up in the right corner.  Click on more and then on Preferences. Change the second setting value to Calendar and then click OK. This will set the applet to go to the calendar whenever it starts. From here, the moon phases are in full display with a graphic for each day.

In one of my previous postings, I featured an animation to show the Moon orbiting the Earth. This is a great applet from The University of Nebraska that has three different views of the effect of lunar phases from Earth’s perspective. At the same website, I also found a really useful animation that shows how the effect of the moon’s gravity and our proximity to the sun sets up the tides.

See how far you get with these suggestions. You can even howl if you like!!

Naked Eye Lunar Observing Pt 2

November 30th, 2017

In this post, we’ll continue the discussion of naked eye targets on our Moon. In the first post, we looked at some of the larger mare that present themselves during the week from new moon to 1st quarter. Let’s “follow the terminator” and look for some more challenging objects to be found during the week up to 1st Qtr. We’ll use some of the so called “Pickering Dozen” to add to the hunt. I’ll call them “P12″ for short.

When the moon is illuminated “half way” on the right side, there are fewer of the prominent craters that appear later on. However, if you have located Mare Serenitatis and Mare Tranquillitatis, you can use these to find some more challenging mountains and regions on their edges. Between these two large features is a thinning kind of peninsula known as the Plinius Region, named for the crater in its vicinity, Plinius. You should be able to make out this feature to the left of the field at the juncture of both of these large features.

Another of the P12 is immediately to the left. Mare Vaporum, The Sea of Vapors. At first quarter, this feature will be just to the right of the terminator just above the equator. It’s a smaller mare that looks a bit like an extension of Serenitatis to the south west.  That will be our reference point next time when we hike the Apennine Mountains!

Naked Eye Lunar Observing Pt 1

October 14th, 2017

This is the first of (hopefully) several posts that discuss naked eye targets on our Moon. Instead of a map or a geographical approach, I’ll “follow the terminator”, the shadow line that progresses across the moon’s surface as the phases advance.

For some easy targets, why not start with the Lunar Mare (maria is singular), those dark and typically large areas on the lunar surface. Before the time of Galileo, most people thought these dark areas were “seas”, hence the name. Now we know they are large flat (dry) plains of fairly smooth basalt that formed 3-4 billion years ago from early volcanic activity.

It’s best to get a small moon map in front of you so you can get oriented. The are downloadable ones like this one from S&T with a printable map on page 10 or this image with different sizes for different screens.

With map in front of you, work from the right back towards the left. This is the way the moon will be revealed as the phases progress from New Moon to Full Moon. It is also the first half of the moon’s full cycle that is visible in the evening. The first obvious object you can see even within the first week is Mare Crisium. As the nights pass, you will then see more of the Mare (The Sea of) - Fecunditatis (fertitility), Tranquillitatis (tranquility), Serenitatis (serenity). By the time of the First Quarter, you will be able to see all of those features.

In the next post, we’ll look for some more challenging objects to be found during the week up to 1st Qtr.

How long is a month?

March 9th, 2016

If you check deeper into the meaning of “month”, you quickly find Earth’s moon right at the center of the explanation. It turns out that the ancient Babylonians pretty much started this examination in the years around 500BC. These early mathematicians and astronomers took extra care in watching and noting the movement of the moon. They came up with several methods and terms to show how the moon tracked around the Earth and how long it took.

There are different ways to describe Earth’s orbit and the orbit of the moon around our planet. Its related to the geometry and timing of those orbits. The method for describing the complete cycle of the moon phases is known as the synodic month. This is the view of the moon from Earth’s perspective and is relative to our point of view. The other method has a more general and wider viewpoint and it is known as the siderial month.

In order to get a better feel for these two concepts, it’s handy to have some kind of diagram or, even better, an animation to show the Moon phases as it orbits the Earth. If you can get your mind around the geometry from your perspective and the solar system perspective (as in the animation), it’s easier to see how “the month” is defined in both of the methods above.

Ultimately, we are talking about lunar calendar systems and there are actually quite a few. The ancient astronomers weren’t just moon gazing but trying to understand what they were looking at. Their persistence lead to what is now a very refined but kind of crazy way of showing what month it is. After all, we want everyone to know our Birthday in time or maybe we just want to take a month off!

Autumn targets sans planets

September 9th, 2015

These last couple of months have seen the gradual westward track of Saturn. It’s way too early in the year for observing Jupiter. Uranus and Neptune are up later but they aren’t easy to get in a small scope. The evenings are getting dark a little sooner now, so, why not work on finding other nice objects to look at.

Well, check the Messier catalog first. A few choices there. Maybe a planetary nebula or two. Check. Galaxies? Yep. How ’bout stars with color. Yep. Several of those to enjoy. Of course, there’s always the standby - double stars! You never run out of them. The links below will take you to Wikipedia for more details. So, here goes.

First, the Messier objects - M57, the Ring Nebula still one of the best planetary nebula; M11, The Wild Duck (open) Cluster in Aquila, a good wide angle object for binoculars or low power scopes; M45, The Pleiades, another great open cluster, is up later in the evening. For galaxies, there is of course M31, The Andromeda Galaxy. And if you look lots of stars in one view, you can’t go wrong with two of the best globular clusters - M13 in Hercules and M15 in Pegasus.

Two other planetary nebula are in the NGC Catalog and high overhead - The Blinking Planetary (NGC6826) in Cygnus and The Blue Snowball (NGC7662) in Andromeda. Both are slightly brighter than M57, but they benefit from averted vision. So look off to the side slightly in your field of view to get a better view.

For colorful objects, you’ll be seeing red! There’s Herschel’s Garnet Star in Cepheus, a very nice red super giant star; there’s also Antares in Scorpius, and also Arcturus in Bootes, both a very noticeable orange.

Finally, for doubles, there’s Albireo, in Cygnus and Kappa Her in Hercules. Enjoy!!!

The Lunar 100

August 14th, 2015

If you are on a mission to discover our Moon and your looking for a detailed observing guide, one of the best ones to start with is Charles Woods, Lunar 100. For a number of years now, Charles has written a frequent column about the moon in Sky and Telescope magazine. He came up with this list of 100 favorite objects and published them in 2004. It’s a great reference and the resources below will get you started.

The revised Sky and Telescope reference article is on this page, but there is also a Lunar 100 page on Wikipedia. The table in the second link is easier to work with and has many of the objects hyperlinked for further study. However, the S&T article has the Rukl chart reference number for most of the objects. Antonin Rukl’s Atlas of the Moon is one of the definitive books with all hand drawn maps that are indexed.  There is a useful wiki reference on the web if you can’t find his book. For a printed hold-in-your-hand quide, Shop at Sky has a nice laminated reference on a card. I’ll have more on the Rukl Atlas in a future post.

Summer Geometry

June 12th, 2015

The night sky is peppered with all kinds of star patterns that have fascinated human kind for untold centuries. These patterns were thought to be gods and creatures of all kinds, kindly (mostly) looking over our affairs here on Earth. For the grander groups of stars, we save the name constellation. But sometimes smaller groups appear that have an even grander attraction. We call these patterns either within (or without) their constellations asterisms.

One of the most recognizable asterisms in the sky is the Summer Triangle. Unlike many other asterisms that are confined to one constellation, with the Summer Triangle, you get three for the price of one! The key stars in The Triangle are as follows: Vega in the constellation Lyra (The Lyre), Deneb in Cygnus (The Swan) and Altair in Aquila (The Eagle). Vega is the brightest of the three and easy to find through the summer into early Fall. Once you get to know how the Triangle is placed in the sky, you can also use it as a guide to other constellations and stars.

Follow the links above to the different objects. You’ll find that the three constellations have long been associated with birds of some kind, no matter what culture is gazing up. If you’re keen to investigate the mythology, check your local library for Richard Hinckley Allen’s “Star Names: Their Lore and Meaning”. It’s one of the great modern resources for ancient astronomy.

Revel in the magic of the Three Mythical Birds of Summer!

Back again!

May 11th, 2015

Yea, yea, yea, I know. I’ve been slack! Not a peep from me in months. Things to do, places to go … and so on. Not that I haven’t been looking up though!

Just got back from California and my second trip to Yosemite in seven months!!! Ya ‘know, you get hooked on stuff and this place just .. well .. ROCKS! And the views of the sky at night with those 3000 foot majestic cliffs looming overhead, the spray of the namesake waterfall in view. Ultra Wow!

Anyhow, another summer, more stargazing and more activities at Fernbank! Stay tuned all!

Clear skies! (hopefully)

Jupiter’s Christmas Return

December 13th, 2014

It’s now well after the Autumn Equinox and the finish of daylight savings time. Shorter days are now the rule, sunsets coming earlier paving the way for evening viewing and just in time for the return of Jupiter in the mid evening skies. So the shift grants even more time for catching the king of planets.

As we approach mid November, the giant planet will be about 4.5 AU from Earth, about 418 million miles away. The apparent magnitude is now about - 2.08 and will be increasing towards -2.15 by month’s end.

Now would be a good time to begin this season’s Jupiter viewing, coming off of the eastern horizon at 9:15PM. By late November, Jupiter will be rising much earlier and easier to catch in the evening hours.

Jupiter will be with us in the evening sky through the end of May. Plenty of time to explore the moons and features of our largest planet.

More on Jupiter in the coming weeks as the King of the Solar System brings another great season of Big Planet views. Stay tuned!