Carnival of Space #92

Carnival of Space #92 is live and ready for your viewing at the Google XPrize blog, The Launch Pad.



The Carnival of Space is a gathering of space blogs. Published weekly, it consolidates news and posts from space blogs everywhere! So head on over and check it out for the latest happenings in the space and science world!

First Test of Radio Telescope

Yesterday, we completed testing on Channel A of our radio interferometer telescope, nicknamed Project Odin. This telescope is basically a direct conversion receiver (at 20 MHz), with a highly selective RF front-end. The front-end gave us quite a struggle to get it working, but alas, we can listen to decametric emission now! Unfortunately, the Sun has been pretty quiet the last few days, so we don't have much data yet. I'll be sure to post anything we observe today. I think we've got a pretty good location staked out for testing today, and hopefully we can get some Solar noise! Nice thing is the typical Ohio weather (clouds) won't affect observation. Pictured below is the receiver and me testing it.

PCB board with channel A complete.

Me listening to the sounds of space.

A sample of typical data from the telescope is shown below. We're not totally sure what this example came from, but it most likely is of Solar origin. We didn't get the telescope set up until dusk, and the Sun has been mostly quiet recently so this is mostly what we got for data. We did, however, show that the radio signal level decreased as the Sun set, so the amplifier is indeed working.




Clear (radio quiet) skies!

How to Find Comet Lulin

After receiving many questions as to where to find Comet Lulin, I've made up a finder chart to share with you all. This chart shows the comet's position on February 23rd, 24th, and 25th. It also includes the general path the comet will take after its closest approach on February 24th. To orient yourself to this finder chart, go outside and look East. Find the sickle shaped asterism seen in the chart as the right side of Leo. Now you can use the chart to find Comet Lulin.

Click here for a more printer-friendly chart.

Closest Approach

Comet Lulin's closest approach will be on February 24^th, 2009 at a distance of about 61 million kilometers. By now, Comet Lulin is predicted to be 5^th magnitude, which means it could be visible to the naked eye in rural locations. The most interesting thing about closest approach, however, is the comet's ridiculously high apparent velocity. Comet Lulin will be speeding along at more than 5° per day! This means that in a telescope or binoculars, one will actually be able to see the comet's apparent motion against the background stars! This effect is a must-see, and does not present itself often.

An Eclipse As Seen From the Moon

Ever wonder what an eclipse would look like from the Moon? Well now you can know, because JAXA's Kaguya spacecraft has taken a picture of one.



Taken on February 10, 2009, this image shows Earth eclipsing the Sun, as viewed from Lunar orbit. This is the first ever picture of a solar eclipse from the Moon.

Courtesy of JAXA.

Check out Galaxy Zoo 2!

Would you like to get involved in some deep space research? Sound too difficult or like it requires a degree in astrophysics? Not necessarily! You can help astronomers analyze data from your very own home. Galaxy Zoo is a project to classify the galaxies in the Sloan Digital Sky Survey, which covers a large portion of the observable sky. Galaxy Zoo 2 has just been launched and provides some new classification options.



The original Galaxy Zoo asked users to classify galaxies as elliptical or spiral. Quite simple in its goals, Galaxy Zoo gathered an unbelievably large amount of useful data. Now, with Galaxy Zoo 2, astronomers would like your help classifying over 250,000 of the best galaxies visible to us! The new Galaxy Zoo 2 asks not only whether the galaxy in question is elliptical or spiral, but also asks for several other traits, and any "odd" or interesting features. Each galaxy is analyzed by numerous users, so as to make the system more error-resistant.

All you have to do to participate is sign up for a username and password at www.galaxyzoo.org, check out their quick introductory course, and start classifying galaxies by a few simple characteristics!

Clear skies!

An Alternative to the Clear Sky Chart

Recently, Andrew Cool, from South Australia wrote to me with a suggestion to check out SkippySky, an Australian alternative to the Clear Sky Chart. So you might think, what would an Australian website know about my weather? Quite a bit, actually. SkippySky uses global model data to provide an international astronomy forecast (so it's not limited to North America). The nice thing about SkippySky is that it shows not only what the astronomy conditions will be like at your specific latitude and longitude, but what the surrounding conditions will be like as well. It kind of reminds me of the radar displays one might find at a local weather website. This can be useful when determining whether to set up the scope or not. The features of SkippySky allow you to view total cloud cover, low- medium- and high-cloud cover, transparency, dew risk, seeing, and several other parameters. So give SkippySky a try next time you go observing. I know I will be trying it out!

Clear skies!

A Really Cool Messier Object Log

Yesterday I found a really cool Messier Object log while using StumbleUpon. It's called TUMOL, short for The Ultimate Messier Object Log. There is a separate page for each Messier Object, complete with fields for atmospheric conditions, reports, and a picture and finder chart of each object.

TUMOL is available either as an application for Mac or Windows, or as a printable PDF file. I chose to download the PDF and print it out so I can put it in a binder and use it at the telescope. I was previously using the Telrad charts to mark off when I've found certain objects, but this is going to be much more organized. I think because of how nice these logs are, I'm going to start over with my Messier count, just as a challenge!

On this same website are similar observation logs for Caldwell Objects, and one for "overlooked objects". So check it out, these logs could be useful for any astronomer observing the Messiers.

Clear skies!

Carnival of Space #90

Carnival of Space #90 is live and ready for your viewing at 21st Century Waves! This week's edition has a special Valentine's Day theme.



The Carnival of Space is a gathering of space blogs. Published weekly, it consolidates news and posts from space blogs everywhere! So head on over and check it out for the latest happenings in the space and science world!

Take Back the Night!

Dark Skies Awareness, an IYA2009 Cornerstone Project, is attempting to spread awareness of light pollution issues during the International Year of Astronomy. One of the main goals of this project is to map light pollution levels across the globe. Their citizen science campaign, GLOBE at Night, aims to use data gathered from amateur astronomers and everyday people to show the impact of light pollution on our night sky. The GLOBE at Night campaign runs from March 16th to March 28th.

Attached is a copy of their letter to IYA participants.

TAKE BACK THE NIGHT!
JOIN THE GLOBE AT NIGHT CAMPAIGN, 16-28 MARCH!

At least 2 out of 5 Americans, 1 out of 6 Europeans and 1 out of 10
people worldwide have never seen 90% of the stars in our night sky.
With half the world's population now living in cities, this problem is
only getting worse. Yet you can easily be part of a local solution to
a global problem.

Take back the night! Take a few minutes to monitor your local night
sky brightness, place your measurement on-line noting your location,
date and time and within a few weeks see a map of light pollution
levels worldwide.

Be part of the "GLOBE at Night" citizen-science campaign and make a
world of difference! The GLOBE at Night campaign runs March 16-28,
2009. Help preserve our natural heritage for generations to come. Find
out more information at www.globe.gov/globeatnight . GLOBE at Night is
an official International Year of Astronomy Dark Skies Awareness
cornerstone project.

To learn more about other IYA2009 Dark Skies Awareness cornerstone
projects and the effects of light pollution, visit
www.darkskiesawareness.org

The Effects of Exit Pupil

Every so often, you might hear astronomers mention the exit pupil of certain eyepiece/telescope combinations. While exit pupil is more commonly discussed when considering binoculars, it is also quite important to telescope users. So what does it all really mean? Also, how can this exit pupil affect my views through a telescope?

The exit pupil is the image of the objective element as projected by the eyepiece. Thus, all light collected by the telescope passes through the exit pupil. Ideally, the exit pupil of the telescope should be approximately the size of the pupil in your eye. Any larger and light might be wasted by not entering the eye's pupil.

Calculating Exit Pupil

Exit pupil is defined as the objective diameter divided by the magnification. So to find your telescope and eyepiece combo's exit pupil, take the focal length of your telescope and divide it by the focal length of your eyepiece. This is the magnification of your telescope and eyepiece combo. Now, divide the objective diameter by this magnification. Make sure you do this all in the same units, i.e. completely in millimeters. The result is your telescope and eyepiece combo's exit pupil. So,



For example, my telescope has an objective diameter of 254 mm. If I use a magnification of 40x, I would have an exit pupil of 6.35 mm, near the 7mm "maximum" available to young eyes.

Find Your Eye's Pupil Size

In order to fully understand the effects of exit pupil, you should know the maximum dilated pupil size of your own eyes. This sounds like it might be difficult to measure, but is not as hard as it sounds. Go into a dark room and let your pupils adjust for a minute or two. Take a piece of dark paper, and cut two slits in it, spaced a certain distance apart. Start with 7 mm and work down. You will be able to see two images through these slits. When the two images just barely touch, you have reached your pupil size. Pupil size typically decreases with age. Young people may have pupil sizes over 7 mm, but will sharply decrease between the ages of 30 and 60 to 6 mm and below.

Also, check out Mang's page on how to find your pupil size using a camera!

The importance of this is that if you have a pupil size of 6 mm, any exit pupil over 6 mm is a waste of light! Thus you are not using the full aperture of your telescope. Using an exit pupil that is the same size of your eye's pupil will allow you to see the widest field of view and see the "richest field" your telescope can provide. Keep this in mind when pricing your next eyepiece purchase!

Clear skies!

Project Odin Update

Lately, I've been spending a lot of time working on our senior design project, a radio interferometer telescope. We've made a lot of progress lately, having nearly completed the design phase. The simulation in OrCAD PSPICE is complete, and it looks like we've got the system as optimized as we can get it. The PCB design is half-done, and all we have left after that is construction and gathering data (assuming all goes well). I ran a test last night on a makeshift antenna we constructed and got much more signal than I was expecting. This is good, because now we can do away with some gain, and get better results!

I'll post further results as we get them.

Block diagram of our Interferometer Telescope.

RF preamplifier.

Audio amplification (downmixing section not shown).

Frequency response of the radio's front-end from low frequency to high frequency. Input signal level is 1 microvolt.

Clear skies!

Astronomy Calendar, February 2009

The following is a list of celestial events occuring during the month of February 2009.

• February 3 - The Moon occults M45, the Pleiades.


• February 5 - Minima of Algol.


• February 8 - The Moon is 1.5 degrees South of M44.


• February 9 - Full Moon, also a penumbral lunar eclipse will be observable for those in the Northwestern North America and Asia, beginning at 12:38 UTC and ending at 16:37 UTC


• February 17 - The Moon is 0.04 degrees North of Antares.


• February 23 - Mars is 1.7 degrees South of the Moon.


• February 24 - Comet Lulin (ephemeris) makes its closest approach. Be sure to catch this comet as it is quite the unusual comet! Titan will cast a shadow on Saturn from 10:53 UTC to 13:09 UTC.


• February 27 - Venus is 1.3 degrees north of the Moon.

There are no major meteor showers in February. If I find any other events of interest, I'll post them here.

Clear skies!

David Helfand on Drake's Equation

In 2006, Columbia University professor David Helfand gave a talk on the modern interpretation of Drake's equation. This equation is theorized to represent the number of intelligent societies in our galaxy. At the time of its creation, the equation had many unknown terms. Since then, many of these have been scientifically and statistically found to great accuracy. Helfand's talk on the Drake equation is informative and easy to follow. If you've got a half-hour to spare, I would definitely recommend it. Video embedded below (some feed subscribers may need to visit the website).