20-21 January 2019: Total Lunar Eclipse

We have a splendid opportunity to see a total lunar eclipse this January. It will be taking place late on a Sunday night into the early hours of Monday morning. That Monday is also Martin Luther King, Jr. Day here in the USA, so many schools will not have classes that day. Eclipse timings are given in the above graphic, in Universal Time.  Converting that to the various USA time zones: 

Event Pacific Mountain Central Eastern
Partial eclipse starts 7:34 pm 8:34 pm 9:34 pm 10:34 pm
Total eclipse starts 8:41 pm 9:41 pm 10:41 pm 11:41 pm
Total eclipse ends 9:43 pm 10:43 pm 11:43 pm 12:43 am
Partial eclipse ends 10:51 pm 11:51 pm 12:51 am 1:51 am

Usually the real eclipse visibility starts to take place late in the penumbral phase approaching the first contact of the umbra. If you have not seen a lunar eclipse before, it is quite a special event. The moon will appear to have a charcoal chunk missing from it as the eclipse progresses.  Deeper into the eclipse, the moon will take on a rusty red hue caused by the sunlight passing through the earth’s atmosphere before arriving at the moon. Telescopes are not required, as one can see the whole event easily with the eye. Binoculars and telescopes will offer a nice closeup view.  Photography of the event is a relatively simple affair. A good tripod and telephoto lens will work well with the moderate shutter speeds required.  Tracking is not needed.  An example of a series of photos I took of the last total lunar eclipse is below. The camera was a Nikon D7000 with 200mm telephoto on a tripod. Click for a larger image.

What is a Quindar Tone?

Ever watched footage of the Mercury, Gemini or Apollo space projects? When Houston talks to the astronauts, there is a beep, then some talking then another beep? Yep – those beeps are Quindar Tones. If you listen carefully, the tones are not the same pitch: there are two distinct tones, one at 2525Hz and the other at 2475Hz. They are both 250ms in length…. like these:

What are these tones for? What’s going on? Why the beeps?  Well, it all boils down to older technology. Back when they were shooting astronauts into space on top of missiles (some more controlled than others), eventually they got people into orbit. As astronauts orbited the Earth, they needed some way to talk to them, even when their space capsules were not within the line of sight of Mission Control in Houston, Texas. Communications centers and tracking stations were built around the world, each with the ability to talk directly to the space capsule as it orbited on by. Mission Control then had telephone lines to each of these stations around the world. These lines were dedicated lines, and expensive. The tones were used as a method to control when the remotely located transmitter was transmitting, and used the phone lines to send these remote control tones as audible beeps. Both tones originated at Mission Control…. like this:

  1. Mission control needs to say something to the astronauts in space. They push the push-to-talk switch.
  2. This send a 2525Hz intro tone to the system.
  3. The remote communications station receives the intro tone, and turns on the transmitter to the radio antenna aimed at the space capsule.
  4. Voice communications takes place.
  5. When done, Mission control releases the PTT switch, and the 2475Hz outro tone is sent, thus turning off the system. The remote transmitter is off.

An example for you is below. Note that the Quindar tones only take place just before and after Mission Control speaks. The astronauts do not initiate any of the tones. They make all radio calls into the “blind” so to speak, hoping that some ground tracking station is picking them up.

Now, you might wonder about the issues here. If an astronaut were to also talk at the same time, they might pick up a Quindar tone on their audio and retransmit it back to the ground and cause all sorts of troubles down on the Earth side of things. Yep – that was a problem(!) so engineers made their best effort to prevent the tones from even reaching the astronauts by placing a filter into the stream of all uplinked audio sent to the capsule. These filters were simple notch filters centered on the tone frequencies…. not perfect, by any means, but it worked, generally.

The name “Quindar”?  That came from the organization that invented the system, Quindar Electronics. You can visit their site at:  http://www.qeiinc.com/History.aspx  to see some of their excellent history.

What now?  Quindar tones were used from the early flights of Merucry through the Space Shuttle program. With new methods of telecommunications (i.e. fiber optics, satellite feeds, etc), sending command and control statements to remotely located transmitter sites is a lot easier. There is no need for audible tones these days.

 

 

Cleaning Time!

Every observatory needs basic maintenance, and those here at PEA are no different. I usually cringe at the thought, but cleaning is a part of the requirement… not that I dislike cleaning. I actually really find it meditative, and a clean observatory dome makes me smile. The cringe-feeling comes from the prospect of kicking up a ton of dust, pollen, cob webs, and such… all of which will have to come to rest some place: Hopefully not on any optics! EEEK! Scheduling the cleaning is a whole other game to play, as well. School ends in early June. A few weeks later, the summer school program begins, and then runs for 5 more weeks. Grass is growing and getting cut throughout June and summer, so, why clean if it’s going to get even more dusty and grassy and pollen-dusty…? So… I wait until the end of summer, when there is a cool, dry, sunny day, like today!

Step – one – cover the optics. Then cover the telescope tubes and mounts with trash bags. Open the dome and aperture.

Two – Vacuum the whole place from top to bottom. We have open studs, so there are a lot of nooks and crannies to work through.

Three – Damp wipe of surfaces, and then a scrub of the floor.

Four – wipe down the ladder and other step-stool devices used by observers throughout the year.

Five – wait for everything to be dry. A light breeze and sunny, dry weather help here. Today was a perfect day.

The result? A clean observatory with a bunch of displaced spiders and no more wasp nests. Webs are gone. Pollen and dust are gone. Happiness!

IMG_1947

A clean machine!

A Meeting of Jupiter and the Moon

A nice photo opportunity will be taking place on August 17th just after sunset. Head outside and look to the southwest for the crescent moon. Just a little to the lower right (southwest) from the moon will be brilliant Jupiter. Heading more to the west, Venus will be lighting up the sky. Enjoy!

Screenshot 2018-08-16 09.36.12

The Moon, Jupiter and Venus just after sunset on August 17th.

The Annual Perseid Meteor Shower

Each August, the Earth passes through a stream of comet debris from Comet 109P/Swift-Tuttle.  The comet will not be back our way until 2126… so… I wouldn’t wait up for that one.  Along the orbital path, the comet has left behind small bits and pieces, most no bigger than a grain of sand. These run into our planet’s atmosphere and burn up due to friction. The result of this friction-filled reentry is a meteor, a rapid streak of light through the sky.  This shower usually gives us about 60 meteors per hour at peak, and many fireballs: bright meteors that can even be bright enough to cast a shadow.  How to see it?

  • Pick a clear night closest to the peak, which is on August 12th/13th.
  • Go to a dark sky site: avoid lights and cities. The darker, the better.
  • Bring something comfortable to lie down on: sleeping bags are good.
  • Bring food, drink, and bug spray if needed for your location.
  • Spend the night time hours looking up at the sky! No optics required other than your eyeballs.
  • Avoid lights!  No cell phones. No flashlights. Your eyes take between 30-60 minutes to become dark adapted, and you lose that dark adaptation instantly if you see a light. Avoid lights!
  • The shower appears to come from a spot in the sky in the constellation Perseus. This rises just before midnight, so best observing will be after that, into the morning hours.
  • Have fun!

 

Polar Alignment with a CCD Imager

This is not for the faint of heart. You need to know how to use a CCD imager and your telescope. I write this here, because there are so many websites with INCORRECT information about this process. Some miss the point completely. All this does is mess with your head and mess with your gear. This method works. Trust me.

Polar Alignment with CCD

This is for permanent installations, as it can take up to 3 or 4 hours to complete the whole process to the point where your mount is perfectly polar aligned. The result is that you no longer have to worry about declination drift during imaging. You still have to worry about periodic error from your mount’s drive, but any good autoguider will take care of that. These instructions assume that you know how your CCD is aligned on the scope (which way is N, E, S, W on the images). In all cases, you will be monitoring North-South changes in a star’s position on your CCD images. IGNORE any east-west drift.

Polar Axis Altitude Alignment:

1. Manually polar align your mount to the best of your ability. Some mounts come with polar alignment scope in the polar axis shaft. Use it! This will actually get you close enough to take 5 to 10 minute integrations without doing the rest of this list! You will depend on your autoguider.

2. Aim your telescope at a star low on the eastern horizon and on the celestial equator (close is good). Faint stars are ok. You do not want them blooming.

3. Take 15 30-second long integrations of that star. Some people prefer to take one 5 minute long shot of the stars to see its path, but it works just as well to see the star’s position move due to drift via snapshots. DO NOT move the mount in any way during these shots. Just let the RA motor do its job.

4. Now to fix your drift! In this step you move the mount’s permanent polar axis depending on the way the star has drifted on your images.

a. If the star drifted north on your images, then move the mount’s polar axis down a tiny(!!) bit.

b. If the star drifted south on your images, then move the mount up a tiny(!!) bit.

5. Repeat steps 2 through 4 until you see NO DRIFT in 5 minutes. Want better? Go for longer. You will find that you can use the centroid tool in your image processing software and get excellent results in about 30-40 minutes.

Polar Axis Azimuth Alignment:

1. Aim your telescope at a star on the meridian and on the celestial equator.

2. Take 15 30-second long integrations of that star. Some people prefer to take one 5 minute long shot of the stars to see its path, but it works just as well to see the star’s position move due to drift via snapshots. DO NOT move the mount in any way during these shots. Just let the RA motor do its job.

3. Now it is time to fix your polar alignment’s altitude to perfection! Be sure to make VERY SMALL adjustments to the polar axis at this time.

a. If the star drifted to the north in your images, then slightly move the mount to the east.

b. If the star drifted to the south in your images, then move the mount to the west.

4. Repeat steps 2 and 3 above until there is NO DRIFT in your 5 minute series.

Congratulations! Your mount is polar aligned. You will likely not need to adjust this again until you swap out telescopes, have an earthquake (more common than you think!) or someone fiddles with a knob or two on your mount (also not all that uncommon as you think).

Spring: the time for planets. They’re Back!

Now mid-March 2018 and there are planets in the sky!  Here are some of the notable moments.

If you look to the west right after sunset you will catch bright Venus and fleeting (and fainter) Mercury. On March 18th, just after sunset, you might also be able to catch the very young, sliver moon, low on the western horizon.

March 18th 2018 looking west right after sunset.

March 18th 2018 looking west right after sunset.

Are you and early riser? Then you will be able to catch the other bright planets, Mars, Jupiter and Saturn.

Jupiter, Mars, Saturn and the Moon visible at about 5:30am looking southeast on March 12th 2018.

Jupiter, Mars, Saturn and the Moon visible at about 5:30am looking southeast on March 12th 2018.

 

A Casper Saturday: People Arrive!

The town of Casper, WY is now hopping along. A lot more people are here today. We started out with a visit to the Geology Museum on the southwest side of things. They have an excellent display on geologic time along with representative minerals and fossils from each period/era. They also have their very own T.rex skeleton, a nice surprise. It is being slowly picked out of the encasing rock….

So, there was a lot of good paleontology to enjoy there for sure!

Back into town, the place is swinging. Lots of people wandering about with geeky T-shirts… yes, these are eclipse watchers for sure. The town has closed off the central area for shops to show off their goods, for people to mill about, to have a quick bight to eat/drink, and relax in the summer sun, a hot summer sun, pushing to 90F. The skies today: crystal clear. Absolutely lovely.