Quick Crescent Moon Pics

From a little star party on the west side tonight.

Lots of Earthshine on the crescent Moon.  I flashed the foreground to illuminate it…only have a built in flash.  Might be my next investment: external flash.

Equinoxes

Today is the Fall Equinox…and its finally in the 60’s at night here!  Just in time for our Equinox, Cassini has released a spectacular image of Saturn taken on its recent equinox.

This is not one picture, but a mosaic of 75 images taken by Cassini!  Download the full 7227×3847 image if you dare!

Saturn takes a lot longer to go around the Sun, so it’s equinoxes occur about every 15 years.  The rings are almost edge on to the Sun, so they are not brightly illuminated.  Cassini was out of the ring plane when it took this picture so we get a nice view looking “down” on the rings.  They released some other images as well you can check out.

Just for good measure, the New York Times profiled the head of the Cassini Imaging Team, Carolyn Porco. I have met her a few times and she gives great Saturn talks.

A Night @Kitt Peak

I just got back from out Project Astro workshop night at Kitt Peak.  Spend most of the evening showing teachers objects through the Galileoscope including Jupiter, Mizar, M4, M7, M8, M13 and M31.  Not a bad collection for a little scope.

I did manage a couple of night shots.  Couldn’t resist getting the Milky Way over one of the domes on Kitt Peak.I also took a shot toward Tucson of the lights.  Remember Tucson has good lighting ordinances so note the lack of upward directed lighting,  You still get some light…hey, there are a lot of people down there!

Good night…another day of the workshop tomorrow!

How Many Licks and Other Fermi Problmes

You might remember the classic old commercial that poses the question “How many licks does it take to get to the center of a Tootsie Pop?”  The wise old owl licks twice, bites one and proclaims the answer is three.

Now author Aaron Santos has taken a stab at the question in his new book How Many Licks? Or How to Estimate Damn Near Anything. He takes on what are commonly called Fermi problems.  Fermi problems are basically exercises in estimation.  You take a problem, make a few quick reasonable assumptions, and try to figure out a reasonable (although not exact) answer.  The legendary Fermi problem is Fermi estimating the strength of the atomic blast at Trinity by observing how far the blast wave blew some paper.  Knowing how far away he was, he got a pretty good estimate of the strength of the blast.

I heard about this book on the podcast the Naked Scientists.  Naturally, they had to estimate how many people are having sex in the world at any given moment (a question sure to get the attention of high school students!)

I used these when teaching.  They are great exercises in creative thinking.  You can probably do some if you give it a shot. How many gallons of gasoline are used each year in the U.S. by automobiles?  Well, you have an idea of how many cars there are, how far the average U.S. driver drives per year (my car insurance statement tells me this!) about what the average fuel economy is and you can get a reasonable number with a basic four function calculator (and if you are only interested in the nearest power of 10, you might be able to do it in your head).

One of my favorites was when my students asked me if there was a google (a 1 followed by 100 zeroes) of atoms in the universe.  I didn’t know the answer but quickly started jotting down some figures on the board (average density of the universe, size of the universe), got out my four function calculator, and quickly pronounced no.  Off by many powers of 10.  I got about 10^79 atoms which puts me nicely in the range of accepted estimates.

Fermi problems also serve as a good B.S. detector.  Earlier this year with Obama’s stimulus plan, a bunch of chain emails proposing other solutions that were allegedly cheaper.  One such email proposed giving everyone over 50 $1 million to retire to solve unemployment.  Well, a quick check of the math (that I could do without a calculator) put the cost of this proposal at about $40 trillion (which is a lot more than $787 billion).  For reference, the entire U.S. economy is about $14 trillion per year.  Obviously people need to be able to estimate things a little bit better before passing on chain emails!  Another one claimed that the stimulus package amounted to more than $1 million per day every day since Jesus was born.  I heard this, estimated the number of days in 2,000 years, and that one turned out to be true.

Fermi problems have a wide variety of applications.  You can use them to figure out if you are being charged too much at the store or to see if the chain email your crazy uncle sent you is total nonsense. They are easy and one of the more powerful and useful tools that everyone should have in their mathematical toolbox.

The Crystal Cave

I am going to look down today instead of up.  Just last week, there was an expedition to the Crystal Cave of Giants in Niaca, Mexico.  This cave was discovered in 2000 and contains some spectacular crystallized gypsum.

You can see that they aren’t kidding.  The suit is due to the fact that it is hot and humid in there…112 F (50C ) and 90% humidity.  You don’t want to hang out there long without a cooling suit.  The crystals are up to 11 meters long and weight up to 55 tons.

This is not exactly my field, so I will let you read the account of the journey and see the other pictures. National Geographic has a nice story summarizing how they formed as well.

Return of the Hubble…

You might recall a few months ago there was a highly publicized Space Shuttle mission to repair the Hubble Space Telescope.  With the exception of an image of the recent impact on Jupiter, Hubble has been quiet.  Too quiet.

When new cameras are installed, it takes time to power everything up, test it, take calibration images, tweak your image processing routines, etc.  But the wait is finally over.

Hubble released a whole slew of new images today.  Let’s take a peek.

That is Eta Carina…well, actually only a small part of the system imaged by the new Wide Field Camera 3 (yes, there was a 1 and 2). Eta Carina is a spectacular, mysterious nearby system.  Right now we think there are two stars. One of them is huge…over 100 times the mass of our Sun.  They are surrounded by this gas and dust.  The large star erupted spectacularly in 1841 and was the second brightest star in the sky by 1843 in spite of being about 8,000 light years away (for reference, Sirius, the brightest star in sky right now, is about 8.5 light years away).  I only embedded a small image here…check it out in hires.

Now let’s move on to Omega Centauri.

Again, you will want to look at hires versions.  This is only a small section of Omega Centauri which is the largest globular cluster in the Milky Way containing millions of stars. I will wait while you count them (don’t worry, there are only 100,000 or so in this image).

Hubble is back and better than ever.  Be sure to check out the other images released today.

Galileoscope Segment on KUAT

Our local pubic television station had a five minute segment on Arizona Illustrated this week.  I am not on camera, but I was the “set designer” for the segments that took place at the National Optical Astronomy Observatory.   If you look close, you can see my Saturn pic I took through the Galileoscope on one of the computer screens in the background.  You also get a glimpse of Photon Engineering, the firm that did most of the optical design.

Unfortunately, KUAT’s embedding code doesn’t work on WordPress, so you can watch it by clicking here.

Enjoy.

Jupiter Goes Solo

Jupiter is famous for its four bright Galilean Moons.  These are visible through any amateur telescope.  You can watch them move and change positions over the course of a few hours with even a modest telescope (such as the Galileoscope, hint, hint).

You don’t always see all four Moons, however.  Sometimes they pass in front Jupiter or behind it.  It’s fairly common for Jupiter to have three or even two visible Moons.  A few times each century, however, all of the Moons either pass in front of Jupiter or behind it at the same time.  Tonight is one of those times.  From 12:43am EDT  to 2:29am EDT (a more civilized 9:43pm PDT to 11:29 PDT) all four of Jupiter’s Moons will be gone leaving a strangely naked planet.  I have been observing Jupiter for decades and never seen this (I have seen it with only one Moon which was strange enough).  You can check out an animation of what you will see with a telescope tonight or use Sky and Telescope’s Jupiter’s Moon’s Utility to find out what you will see at any given moment.

Unfortunately, it looks to be cloudy here in Tucson tonight.  My telescope is sitting at home on the tripod ready to go outside a moment’s notice should we get a break in the clouds.  I hope others have clear skies for this rare event.

Mount Wilson Threatened by Fire

Historic Mount Wilson Observatory in California is being threatened by wildfires.  The mountain staff have been evacuated as the Station fire closes in.

Mount Wilson is a great old observatory.  It is home to the historic 100 inch Hooker Telescope.  It was the largest in the world when it was built in the early 1900’s and played  pivotal role in Edwin Hubble’s observations that proved the universe is expanding and led to the Big Bang Theory.  Mount Wilson houses several other telescopes as well, including the CHARA array which does some very high resolution interferometry.

You can view the observatory webcam as long as it functions.  I am embedding the current image.

Firefighters are on the scene and hopefully can save this historic site.

Daytime Occultation of Antares

Just noticed that we get daytime occultation of Antares by the Moon on Thursday, August 27th.  It starts at about 4:30pm EDT (1:30pm PDT or MST where I am).  Antares is bright enough you can probably see it during the day with a telescope.  Simply point your telescope at the Moon at little before 4:30pm EDT an look off the Moon’s eastern limb.  You should see the bright star Antares.  It will disappear behind the Moon and reappear about an hour later (looks like about 2:35pm PST in Tucson).  You can find time tables for a variety of cities here.

Unfortunately it looks like the disappearance is not visible from Tucson as the Moon rises just a few minutes too late.  It is tougher to watch the reappearance because you have to look at exactly the right moment (with the disappearance, you can watch the approach so you can see it coming so to speak).  Still, I am not totally deterred.  I have a student who has been doing some imaging work and might look at his class schedule and send him out to set up the telescope with a webcam to see if we can catch!