Venus and the Moon: Just Another Beautiful Evening

Just a nice evening here…it was too cloudy to see Venus during the day, but was clearing around sunset.

Another Good Chance to See Venus During the Day

I blogged this last month and the Moon is back serving as a useful pointer to find Venus during the day.  You will need to wait until the Sun is high in the sky (Venus doens’t rise until well after the Sun).  The Moon is a thin three day old crescent which can be challenging to find in the day, but be patient.  The Moon will be west of the Sun.  Once you find the crescent Moon look slightly above the Moon (for northern hemisphere observers) to find Venus.  The chart below (click to embiggen) was made for Tucson, Arizon at 1:00pm local time.

Venus will be slightly to the west of the Moon at 1:00pm, but the Moon moves about one Moon diameter per hour, so their relaive position may change depending on your time zone and what time you look (you can use Stellarium to make your own chart for your specific time and location).

Now a few tips.  It is helpful if you can stand in a place where a building blocks the Sun from your view.  Venus is best viewed when it hits the fovea, the most sensitive part in the center of your retina where we have the sharpest vision.  Slowly scan around the Moon and have patience.  Once you find it, you will be surprised you have never noticed it before.

The Moon will be moving well to the west of Venus tomorrow.  However, it is still possible to find Venus using the Moon as a guide…I will leave this challenge to you!

Comet Lulin Observing Report and Update

Well, it was finally nice and clear here in Tucson.  I drove out to Saguaro National Park east (at the end of Speedway for those of you who know Tucson).  Comet Lulin was visible naked eye as a small splotch.  And here is a photo with Lulin outlined (click to ebmiggen).

That is a reasonable approximation of how easy it is to see from a reasonable dark site.  You can see it, but it doesn’t jump out at you.  I caught a plane as you can see (the streak toward the bottom of the picture).

Through my 20×80 binoculars on the other hand, WOW!  The tail was very prominent and covered just under half the field of view (probably about 1.6 degrees roughly or a little over three times the size of the full Moon).  Very nice view from a dark site.

There are still a few good chances to see it.  You can find a finder chart at Sky and Telescope. Lulin is heading toward a close conjunction with Regulus on Friday night (the bright star almost directly above it in my picture).  By Sunday night, the Moon starts to brighten the sky and will make observing difficult, so take advantage of the next few days.

Binoculars are enough to pick out the comet, but be sure to get as far away from bright lights as you can for the best view.  It was definitely worth it tonight!

And one other thing I should point out is that Lulin is on a hyperbolic orbit.  If you remember your high school math, hyperbolas never return to the same point twice…Lulin is making its one and only trip through the inner solar system.  I am happy I was able to spend a little quality time with Lulin tonight.

The Galileoscope is Coming!

The Galileoscope is coming!  This is a cornerstone project for the International Year of Astronomy (and, in the interest of disclosure, one I work on).  The Galileoscope is a small, low cost, high optical quality telescope that anyone can build and recreate many of Galileo’s famous observations.  You can see craters on the Moon, the phases of Venus, the Galilean Moons of Jupiter and the rings of Saturn.

The telescope has a 50mm achromat lens with a 20mm eyepiece yielding a magnification of 25x and a nice big 1.5 degree field of view.  A supplied 2x barlow lens can bump the magnification fo 50x.  As an added bonus, you can use the Barlow lens as an eyepiece to construct a true Galilean telescope and see what Galileo had to work with (Galileo used a diverging lens for his eyepiece which is not the ideal configuration…and you can see why!)  Or you can insert your own eyepiece as the holder accepts any standard 1.25″ eyepeice.  The included nut allows you to mount the telescope on any standard camera tripod.  I posted a previous blog entry on my attempts at imaging with a Galileoscope.

The assembly is simple and requires no tools.  The telescope can be put together and taken apart easily multiple times.

There are free educational materials available on the web site covering how telescopes work as well as how to osberve with the Galileoscope.

The Galileoscopes cost $15 plus shipping ($12.50 each if you order 100 or more, say for a school, astronomy club, or just get everyone on the block together to order them).  I have been talking to a lot of people at meetings and there are some college professors who are making this a madatory item for their students in the fall.

When you order a Galileoscope, you have the option to donate one or more to underserved students around the world.

Sorry if this sounds like a commercial.  A lot of people have worked hard and put a lot of time into its development and I want to see a LOT of Galieoscopes out there!

Now back to your regularly scheduled programming.

Comet Lulin Tonight: Updated for Feb 24th/25th

Tonight is the best time to see Comet Lulin.  It is bright enough to see naked eye from dark sites, but probably not from most suburban backyards.  However, even a small pair of binoculars should make it visible from most sites.  I have a pair of 8×42 binoculars and have picked it up with them.

Comet Lulin is farther from the Sun than the Earth right now…in fact, its almost opposite in the sky from the Sun.  It rises shortly after sunset and is visible most of the night until sunrise. The best time to look is around midnight to 1am local time when it is highest in the sky.  As an added bonus, Comet Lulin is near Saturn tonight and visible in the same binocular field! Lulin is east of Saturn tonight. That makes it nice and easy to find…find Saturn (which is bright and you don’t need a telsescope to see) and you find Comet Lulin.  A finding chart is below.

Start by finding the backwards question mark of Leo. You should then be able to pick out the bright Saturn.  Center your binoculars on Saturn, scan slowly west and you should run across the comet!

You can see the comet for the next few days pretty well, but by early next week the Moon will be getting brighter and interfering.  The comet is moving rapidly across the sky, so look for upated charts at sites such as Spaceweather. Comet Lulin rapidly moves away from Earth and will dim quickly in early March.

Happy hunting!

OBSERVING REPORT: I found Comet Lulin briefly last night between clouds and through some haze.  It has a low surface brightntess through 8×42 binoculars but was obvious even in pretty lousy observing conditions.  I will give it another shot tonight.

The Spooky Eyed Spookfish

I like optics so this caught my attention.  The brownsnout spookfish is now the first vertebrate to use mirrors to focus images in its eyes.  You can see the strange looking spookfish appears to have four eyes, but since the two on the left and the two on the right are part of the same structure, biologists consider them two eyes.

Spookfish live at a depth of about 1000 meters where there is very little light.  The two eyes pointing upward (the orange spots) use a traditional cornea to focus light much like our eyes (most of the focusing power of our eyes comes from the cornea.  The lens is used to fine tune the focus for nearby or far away objects…as you get older the lens loses flexibility which is why you may be able to see far away just fine but need reading glasses).  The other part of the eye points downward (the black spots in the image).  Light from below is reflected off a mirror like surface in the eyes and onto the retina.  The mirror shows not only what is directly below the fish, but out to about 50 degrees in all directions (which is useful for avoiding predators!)  There is evidence that the fish can slightly change the shape of the mirror to focus the images much like our lens changes shape to help us focus.

Some animals (like housecats) have a reflective layer called the tapetum to help them see in dim light.  The tapetum lies behind the retina and increases the sensitivity to dim light but does not focus the light.

The spookfish has been known for over 100 years.  However, a live specimen was never caught until recently.  The deep sea is truly one of the final frontiers on Earth with lots of odd treasures waiting to be discovered.

Progress on the Constellation Program

NASA’s program to produce the next generation of manned rockets has been named Constellation. These rockets are designed to take us back to the Moon.

Work is well underway and highlighted in this week’s Big Picture. My favorite image shows the upgraded lightning supression system at Launch Complex 39.
I am really looking forward to seeing hardware for the Ares V, the big one they are building.

The End of the Rainbow

There is an interesting discussion about rainbows going on over that the Orange County Register (a former student of mine sent this to me and asked my opinion) involving a picture that some think shows the end of a rainbow. Some are questioning if the image is photoshopped.  You can see the picture in question on the right.

Okay, rainbows do not have an end. If you have ever been in a plane, you can see rainbows form complete circles! I have seen this and it is pretty cool. What they mean obviously is the point where the rainbow hits the ground. To me, I see what they call the “end” of a rainbow all the time. Sometimes it appears over a mountain, others over the ocean, sometimes over a house.

Let’s back up. In order to get a rainbow, the Sun must be low in the sky. There must be rain on the opposite side of the sky from the Sun from where you are standing. Sunlight passes through the raindrops and reflects off the back. However, as sunlight passes through the raindrops, it also bends due to a phenomena called refraction. Blue light refracts more than red light. Therefore, when the reflected light heads back to you, it has been split up into different colors. You can see the path light takes through a raindrop in the image on the left and notice how the colors separate.

You can fine the center of the circular rainbow by drawing a line from the Sun and through yourself and extend it away on the other side. This will show you the center of the circle somewhere underground (except for rare cases when you see a rainbow right after sunset). The circle forms a cone with you at the tip an an angle of 42 degrees to the rainbow.

So let’s go back to the photo. It was taken on highway 241 North in California at 4:59pm on February 7th. The GPS cooridnates are given on the OCR site. I popped them into my computer and found the Sun was 15 degrees high in the sky at an azimuth of 239 degrees. The center of the rainbow is at 59 degrees putting the left side of the rainbow at about 17 degrees (slightly east of north) which jibes well with someone driving north on 241 seeing this site. Since the Sun is low, we see almost half the circle and this rainbow has a nice steep arc which also agrees well with the time and geometry of the situation.

Some in the discussion argue this is a “sparybow” created by spray kicked up by the car tire (which also gives the nice illusion of the end of the rainbow).  It does appear the tires are kicking up spray that makes the bottom of the rainbow brighter.  However, the person who took the picture says they say an entire arc of the rainbow. That single car could not kick up enough spry to create a rainbow that extends that high in the sky!  I suggest you could call it a hybrid…the bottom part may be a “spraybow” but you definitely have a rainbow there as well.

So what do the people in that car see?  They see a rainbow in front of them!  As you move toward a rainbow, it continually moves away from you.  You can never reach the true end of a rainbow no matter how hard you try.  In fact, everyone sees their own personal rainbow.  The light I see entering my eye comes from a different set of raindrops than a person standing next to me becuase the angles between the person and the Sun change!

So enjoy the rainbows…but don’t go chasing that pot of gold!

Far Out!

George Hrab has posted the full length video of Far on Youtube.

This song is the full length version of the theme of the 365 Days of Astronomy podcast.  Be sure to check out your weekly dose of George as he philosophises on music, politics, religion and skepticism on the Geologic podcast.

Satellites in Collision

There have been small objects colliding in space before, but now we have two full fledged satellites that have run into each other. An Iridium communication satellite collided with an old Russian Cosmos Communication satellite. This collision created hundreds of new pieces of debris that could in turn collide with other satellites. The collision occurred about 500 miles over Siberia.

The first thing most people are concerned about is the International Space Station or Hubble. Both of these orbit a lot lower, so they are not in immediate danger from this debris. However, there are a lot of satellites in similar orbits to these to that are now at increased risk of collision with space debris.

A company called Analytic Graphics created a pretty neat animation of the collision and the resulting debris cloud (based computer models of course).

You can see the debris spread out fairly quickly. When they add all the other objects up there it starts looking pretty crowded.

You can even listen for radar echos from the debris cloud.  Spaceweather is streaming the Air Force Space Surveillance Radar signals from Texas.  The next time to listen is 11:56pm to 12:07am EST tonight.