Archive for the 'astronomy' Category

Jul 18 2015

What does Pluto look like from Earth?

When I host star parties, one of the most enjoyable experiences is to introduce people to Saturn for the first time –  “Saturn Virgins” they are called.  People oooh! and ahhh! and walk around to the front of the telescope to see if I’m fooling them.  The can’t believe that the solar system appears with such 3 dimensional depth and reality.

This is inevitably followed up with “let’s look at the other planets.”   Jupiter is pretty cool, and occasionally shows moon shadows moving across it.  Mars and Venus can be very bright, but Neptune and Uranus are just small dots, barely discernable as disks instead of single dots (as stars look).

But Pluto is a different story.  Besides its demotion from planet to minor planet (a topic which generates immense debate, but which I’m firmly an agnostic), it is really far away.  It is only visible with light reflected from the sun.  The light from sun diminishes according to the inverse square law.  If a planet is 10 times as far from the sun as another, then it gets 1/100th the light.  But that is just the light falling on Pluto.  That light has to reflect and come back to Earth, which is another inverse square law relationship, which makes it an “inverse power of 4” law.  Moving a planet twice as far away makes it 1/16th as bright.   Pluto is very far away, as far as solar system metrics go.  It takes light about 4.5 hrs to go from Pluto to earth.  Kuiper Belt objects become very dim, very quickly.

I have a scale model of the solar system in my back yard.  I shrunk the sun to the size of a golf ball. To scale, Earth is then 12 feet away.  Pluto is 330 feet away.  This is seriously Far Away with Not Much In Between.   And the light we see from Pluto is Magnitude -14 – requiring a serious telescope to see.  Pluto is about 1 million times dimmer than Saturn.

Just before the New Horizons encounter with Pluto, I took some time lapse images of Pluto moving across the sky.  It was impossible for me to see the spacecraft, and even detecting Pluto was a challenge.  I set used my backyard observatory, the Cosmos Research Center, to photograph the sky around Pluto.  This is what I saw:



This image is about 1 degree wide, about as wide as your index finger held at arm’s length.  For those of you who can’t see Pluto yet, here is a close up, showing a zoom area around Pluto:


And for those of you who are still missing Pluto, here is a closeup showing the motion of Pluto over 4.5 hours – the same time that it takes for New Horizons to send information back to Earth.  Pluto’s motion is shown as a sequence of dots, making a thin line across the middle of the frame.  This shows were Pluto was when New Horizons sends a message (on the left), and where it is when we receive it (on the right).


And here is an animated image, showing the motion of Pluto over 4.5 hours.  Look in the center for the dot moving across the image.  If New Horizons sent a message while at the left most point in the motion, Earth would see it at the right most point.


And here is an interview I recorded with Dave Jewitt, the astronomer who discovered the first Kuiper Belt Object beyond Pluto.

I would like to thank Bill Warden, Orange County Astronomers,, for his help in processing these images.




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Feb 03 2013

Chemtrails – a Science Learning Opportunity

Published by under astronomy

In my role as a NASA/JPL Solar System Ambassador,  the number one question I get from school kids is “is there life on Mars (or outer space)?”  My standard reply is, “I don’t know.  Why don’t you become a scientist and be the first to find out?”  That’s why I like astronomy as a tool for engaging the public in science: it touches so many “hot topics” that can be channeled into really good science.

For the past decade or so, people have been asking me if I knew about Chemtrails, which are supposedly part of a conspiracy to holds that some trails left by aircraft are chemical or biological agents deliberately sprayed at high altitudes for purposes undisclosed to the general public in clandestine programs directed by various government officials.

The evidence they point to is that some contrails from jets (the “Chemtrails”) persist and spread out, while others were narrow and dissipated rapidly (which they call “real” contrails).  They then move on to state these “chemtrails” are part of a government conspiracy, and then point to the fact that “the authorities” are denying their existence as proof of the conspiracy.

This theory is popularized on various internet-based conspiracy sites, and is similar to the Seattle Windshield Pitting Epidemic.  This was characterized by widespread observation of previously unnoticed windshield holes, pits and dings, leading residents to believe that a common causative agent was at work. It was originally thought to be the work of vandals but the rate of pitting was so great that residents began to attribute it to everything from sand flea eggs to nuclear bomb testing…. Within a week [of the initial observation], the news and the so-called “pitting epidemic” had reached metropolitan Seattle. As the newspapers began to feature the story, more and more reports of pitting were called in. Motorists began stopping police cars to report damage and car lots and parking garages reported particularly severe attacks.

Several theories for the widespread damage were postulated:

  • Some thought that a new million watt radio transmitter installed by the Navy was producing waves that caused physical oscillations in glass;
  • Some believed it to be the work of cosmic rays;
  • Some reporting seeing glass bubble form right before their eyes, believing it to be the work of sand fleas;
  • Some attributed it to a shift in the Earth’s magnetic field.

The whole “epidemic” came to a halt when folks realized that this was just normal pitting of windshields.

I find that when someone believes in a preposterous theory, coupled with a conspiracy cover that “the authorities” are covering up the facts, it is nearly impossible to talk about rationality.  I am simply aligned with the deceiving “authorities” and thus part of the conspiracy.  As Robert Park says in Voodoo Science:

I came to realize that many people choose scientific beliefs the same way they choose to be Methodists, or Democrats, or Chicago Cubs fans. They judge science by how well it agrees with the way they want the world to be.

My Proposal: Use Chemtrails as a Science Learning Opportunity.

The chemtrail phenomenon proposes a very specific hypothesis: that the emissions from Jet aircraft are leaving behind abnormal trails of vapor and chemicals that can’t be explained as normal contrails.  Contrails are everywhere, and observable just by looking up.

This is great science.  Now, let’s prove or refute this theory.

It turns out that NASA is already way ahead of this.  It is asking citizen scientists, teachers, and students to study contrails, and is even providing resources to do so.  There is even a global reporting system for students to record their local observations.  If there is so much energy to hype the conspiracy theory, let’s turn it into energy to scientifically research it.

And in the tradition of great science, studying this phenomenon from one perspective can lead to another discovery: the contrails play a big role in our understanding of climate change.  They may change the albedo of the planet significantly – and folks all over the world can make simple measurements to contribute to our understanding of this phenomenon.

So, next time I hear someone talk about Chemtrails as a conspiracy, I’m pointing them to this post as a “why don’t you find out for yourself?”




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May 03 2012

David Brin talking at Cosmos Research Center Star Party

David Brin is one of my favorite intellectual sparring partners.  Luckily, he lives nearby, so he was able to drop in at a children’s science star party I held in June 2007.

Here is a video of David’s presentation to the kids, (mostly K-8).

and here is a portrait I took of him:
Science Fiction author David Brin

I started the Cosmos Research Center in a shed in my backyard, and then got lab coats, a logo, a website, and named myself Executive Director. I really enjoy motivating kids to dig deeper into science, which has also lead to my becoming a NASA/JPL Solar Systems Ambassador.


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Mar 27 2012

My first photo from the MoonKam

I’ve signed up the Cosmos Research Center to be a participant in the MoonKam project, which allows students to take pictures of the moon from the NASA Grail Satellites, Ebb and Flow, that are orbiting the moon to measure its gravity.   Scientist Abby chose the spot and typed in the coordinates for this image.

It is an image of the south pole, of the Schrodinger Crater.  It is on the far side of the moon, so it is not visible from the earth.  I’m going to try to print this in glow-in-the-dark ink so she can put it on her bedroom ceiling.


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Oct 11 2009

Stereo images of the moon and a black hole

Published by under astronomy

These are two images of the Cabeus crater at the south pole of the moon taken by the 200” inch telescope from Mt. Palomar on Oct 9, 2009 at the time of the LCROSS moon landing. Click Here to See them They were taken 12 minutes apart. The slight movement of the moon (libration) during this time is evident in the raw video

I took the first and last frames of the video, and put them together above to show a stereoscopic effect. If you cross your eyes so that you create a third overlapping image in the center (“wall-eyed” viewing) you should be able to see a depth to the craters.

And here is another attempt to do a stereo image of a Black Hole.


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