Arguing with a Flerf pt. 2

So I pressed the conversation longer than I really should have. But I did discover a number of motivations behind the obstinate adherence to an easily disproved view of the world. It took more conversation, but his motivations did become clearer.

Total Solar Eclipse 2017
The 2017 total solar eclipse as photographed from central Oregon

To no surprise part of the reason is religion. When he began to quote bible verses in support of his claims of a “immovable” Earth one can begin to see where he is starting from.

Our flat, enclosed, immovable earth is absolute proof of a creator. God is real. We don’t have to believe in Him anymore. We can know it to be true.
Flat earth absolutely destroys the atheist/humanist worldview. Just like that.

Adam Asing in a Facebook Comment

If one begins with the belief that the Earth is flat, it is easy to reinforce that idea in this modern internet age. A thriving community of flerfs form one of the clearest examples of an echo chamber to be found on the net, a cult really. Circulating photos and YouTube videos reinforce the worldview, ridicule the “globe heads”, cement a community together in a belief of “true knowledge”.

Continue reading “Arguing with a Flerf pt. 2”

The ScopeStuff 2″ Crayford Focuser

When shopping for a focuser you face a lot of choices. From the cheap eBay Chinese options to the top-of-the-line Moonlights and Feather Touch. I once again perused these options when buying a new focuser for the Cave Astrola.

ScopeStuff 2" Crayford Focuser
The ScopeStuff 2″ Crayford Focuser mounted to the 8″ Cave Astrola
It has been a while since I looked at what was out there. So I spent some time shopping and wandering website re-educating myself on what the options were.

I considered the cheapest end of the market, a few options found on eBay, and again at the top-of-the-line, machined works of art that cost as much as some telescopes. This time I was limiting the budget for restoring the Astrola, not wanting to spend much more than a hundred on the focuser to keep the cost of the whole effort down.

Continue reading “The ScopeStuff 2″ Crayford Focuser”

Star Party Etiquette

Time to remind everyone of the common rules for star party etiquette. As few simple considerations for your fellow star party participants help make the event more enjoyable for everyone.

Obsession at Kaʻohe
The 20″ Obsession telescope awaiting full dark at Kaʻohe, on the side of Mauna Kea

Not to say these are hard rules, they will get broken. Try not do break these rules… It is simply a matter of courtesy to other star party participants. Be polite and you will be far more welcomed to share the experience under a dark sky.

The points of etiquette below apply to any star party you might attend, with a few added bits particular to our West Hawaii Astronomy Club events.

Continue reading “Star Party Etiquette”

Venus Becomes a Crescent

Even when Venus is high in the sky and well placed for observation I will seldom take the effort of turning a telescope towards the planet. Why? Because Venus is pretty boring to look at. Perpetually cloud covered it has all the detail of a cue ball. It is a white disk with nothing of note to be seen. Yeah, pretty boring. Now turn the telescope to Jupiter.

Crescent Venus
Venus approaching inferior conjunction, 24Dec2013
One exception to this occurs when Venus is approaching, or just emerging from inferior conjunction. As the planet passes between the Earth and the Sun we are looking at the nighttime side of the planet, with only a little of the daytime side to be seen. As a result Venus will appear as a brilliant crescent.

This begins as the planet passes maximum eastern elongation, about two months before inferior conjunction. At this point the planet is seen from the side with respect to the sunlight, the planet will be about half illuminated. In the weeks after maximum elongation the planet will appear ever more crescent.

Venus 28May2012
Venus on 28May2012, about 12°44′ from the Sun
The last weeks before conjunction, as Venus is very low in the sunset, or the first weeks after conjunction as it sits very low in the dawn are the most interesting. During this time the planet is a very fine crescent, quite a beautiful sight in the telescope. Many observers, including myself, have made a point to observe Venus at this time, the one time this planet really becomes interesting to view.

Imaging Venus in the Daytime
Imaging Venus in the daytime a mere 12°44′ from the Sun.
As the planet is quite low in the sky it makes it a challenging telescopic target and distortion by the atmosphere can be troubling, blurring the view.

It is possible to enjoy this sight in the daytime, while the planet is high in the sky, the seeing can be better and the view sharper. Of course this also occurs when the planet is near the Sun, thus extreme caution should be practiced at the telescope to avoid any direct sunlight and possible eye damage.

Planetary Drawings by Galileo
A page from Galileo’s 1623 treatise The Assayer—Il Saggiatore
The phases of Venus are quite interesting from a historical standpoint. The phases of Venus clearly show that the planet revolves around the Sun. The phases were one of the primary arguments used by Galileo in his treatise The Assayer—Il Saggiatore published in 1623, where he lays out many of his ideas on science itself and how observation and experimentation should be primary.

While the the evidence challenged prevailing ideas of the time, some astronomers attempted to explain the phases of Venus by any other means to preserve their Earth centered universe, which led to rather tortured models of planetary motion. But it was clear to most that Galileo was right, the simple and elegant answer was that the Sun lay at the center. The orbits of Mercury and Venus, the phases, along with other observations like the moons of Jupiter, were hard evidence that few could ignore.

In 2017, eastern elongation occurred on January 12th. By now Venus has begun to show a substantial crescent, about 30% illuminated if you look today, Feb 12th. Over the next few weeks as the planet sinks into the sunset, the crescent aspect will thin dramatically.

By the end of February the planet will be only 17% illuminated, another week after that it becomes only 11%, by which time the planet will be difficult to spot in the sunset. Inferior conjunction will occur on March 25th. A couple weeks later and it will be possible to spot the planet in the dawn and observe the now thickening crescent.

Venus Events for 2017

  Date UT Separation Mag
Maximum Elongation Jan 12 47.1°E -4.4
Inferior Conjunction Mar 25    
Maximum Elongation Jun 3 45.9°W -4.3
 
Source: NASA Sky Calendar

Venus in the Daytime

With the Moon only a few degrees from Venus this afternoon, it should be relatively easy to spot the brilliant planet long before sunset.

Venus 28May2012
Venus photographed on 28May2012, about 13° from the Sun in the mid-afternoon sky
Spotting planets in the daytime is not that difficult, both Jupiter and Venus are bright enough to seen in full daylight. Venus is currently near maximum brilliance at about -4.6 magnitude, easily bright enough to see in a clear sky. There are a few helpful hints to make this easier.

Today the Moon will aid finding Venus in the sky as it is about 5° north of the Moon. Having the Moon nearby will not only aid in locating the Planet, it will also provide your eyes something to focus on.

Of course these bright objects will be even more dramatic after sunset when Mars will also be visible nearby.

The Keck Observatory Archive

The data produced by the W. M. Keck Observatory is available for anyone to view. This may come as a surprise to some who assume that astronomers hoard their precious data and jealously deny any access. I have also seen claims by anti-TMT activists who claim that telescope data is secret and access is restricted to some authorized group. It is a common theme I have seen repeated quite a few times during the Astronomy on Mauna Kea debate.

Saturn NIRC2 dePater
An image of Saturn taken in infrared light by NIRC2, image credit KOA/dePater

“There is an appointment signup of experts of bureaucrat choosing and the findings disappear amongst the grant supported or institutions we have no knowledge about” – Claire Templeton in a Facebook comment 16Aug2015

The idea is at least understandable. Much of modern astronomy is fairly arcane to the layman, not easily understood and seemingly mysterious. It does not have to be that way, the images and data are fully public. A small community, including astronomers and amateur astronomers, has learned to use the data to do science, or to simply peruse for their own edification. All it takes is an evening of educating yourself and you have access to a huge array of data.

The astronomers do guard their data and deny others access, but they are only allowed to do this for a limited period of time. This gives the astronomer exclusive use of their data long enough to complete the research and publish the paper. The amount of time they have exclusive use varies by telescope and institution, but it is usually a year or two. For the W. M Keck Observatory the data is usually embargoed for 18 months. Once the exclusive period expires the data is available to anyone and is posted in the online public archive.

Keck’s archive is known as KOA, or Keck Online Archive. Also a nice reference to the beautiful Koa forests that are common on the windward slopes of Mauna Kea. Here you can search and peruse twenty years of Keck data.

Continue reading “The Keck Observatory Archive”

Seeing Planets in the Daytime Sky

We expect to wait until darkness falls to observe the stars and planets. While the Sun and Moon are normally seen in the daytime sky, there are other objects that may be observed.

Crescent Venus
Venus approaching inferior conjunction, 24Dec2013

Both Jupiter and Venus are bright enough to see fairly easily in full daylight if conditions are right. Saturn can be observed with a telescope if you can locate it. Very occasionally, we are treated to a daytime visible comet.

Jupiter and Venus are the easiest, you simply need to know where and how to look, but once glimpsed they are fairly easily seen. It is the knowing how that makes it possible. Try these simple hints…

  • Try when the planets are far from the glare of the Sun, in the first hours after dawn or last hours of the day are best.
  • Clean air is necessary. If the air is hazy, dusty or smoggy it will hide the planets from view, particularly when near the Sun. There will just be too much solar glare to pick out the planet. For the same reason try when the planet is high in the sky and you are looking through much less air.
  • The human eye will relax and defocus if there is nothing to focus on. This happens when looking at a plain expanse of blue sky. You could be looking right at the planet and not see it. A few puffy clouds around, or better yet, the Moon, will give the eye something to focus on, allowing the planet to be easily seen.
  • Put the Sun out of sight to reduce glare. Simply position yourself in the shadow of a tree or building to get a better view.
  • Pick a day when the Moon is near the object you are looking for, it will provide a simple signpost to the correct location.

It is this last hint that can be particularly useful. Looking ahead with the aid of a planetarium program you can find a day when the Moon is near the planet. Using the program to estimate the position with respect to the Moon you can look in just the right place. If you get it right the planet will appear as a bright star-like object. Once you see it you will wonder how you ever missed it in the first place.

Have a try.

Comet? Where?

There is one question we all have to ask when a beautiful comet graces the skies…

C/2007 N3 Lulin
Comet C/2007 N3 Lulin on the evening of 26 Feb 2009
Where to look?

Like any other solar system object, comets move against the sky. Even worse, when close to the Earth or Sun they can be moving so quickly against the stars that coordinates quickly become out of date. Aiming a telescope using coordinates a day old, or sometimes even only an hour old will result in a view of empty sky. A few stars perhaps, but no comet.

You need a table of coordinated calculated for regular time intervals, an ephemeris. Alternately you need a set of coordinates calculated for the exact time you will be looking.

Continue reading “Comet? Where?”

Lahaina Noon

Living south of the Tropic of Cancer we get to experience an interesting phenomena that folks outside the tropics will not see. There are two days each year when the Sun passes directly overhead. In the islands this event is called Lahaina Noon.

Spring Lahaina Noon for 2013
Location  Date Time
Hilo May 18th 12:17pm
Waimea May 19th 12:20pm
Kahului May 24th 12:23pm
Honolulu May 26th 12:30pm
Lihue May 30th 12:36pm

 
Lahaina noon occurs twice each year as the Sun appears to move northwards with the spring and again as it moves southwards in the fall. For the islands of the Hawaiian archipelago the first day is between May 16th and May 31st. The second Lahaina Noon will be between July 10th and July 25th.

The date on which this event occurs each year depends on your exact latitude, the further north the later in the spring it will occur. Thus the day for Lahaina noon will vary by eight days from Hilo to Honolulu, and another five to Lihue. As you approach the Tropic of Cancer at 23°26’N Lahaina Noon will occur closer to the summer solstice. The date will also slip a little due to the out of sync nature of our seasons and our calendar. This is the reason we insert a leap year into the calendar every four years.

This year Lahaina Noon will occur on May 18th for residents living in Hilo, or May 26th for Honolulu. It is also important to remember that the Sun is not directly overhead at 12:00 exactly. As the islands lie west of the center of the time zone, true local noon occurs up to half an hour after 12:00.