2012 Transit of Venus

2004 Venus Transit

2004 transit of Venus through a small telescope. Click image for source.

Next Tuesday, June 5th (June 5th in North America / June 6 eastern continents), you’ll have the opportunity to observe something that you’re extremely unlikely to ever see again. Over the course of a few hours, Venus will cross in front of the Sun from the vantage point of Earth. Venus will appear as a small black dot against the bright blazing disc of the Sun. Just like the annular eclipse from a couple of weeks ago, it is NOT SAFE to view this event directly. Here are a few ways to view it:

Disposable solar shade glasses – This is the cheapest and simplest method. These are the same glasses you would use to view a solar eclipse. They’re generally made of cardboard and have extremely dark film for lenses. When looking through them, you cannot see anything except for something as bright as the Sun. If you can see the surrounding landscape through them, they are NOT dark enough and you are at great risk of damaging your eyes.

Pinhole projection – If you’ve got clear skies and an overhead Sun, you can project the image of the Sun (and transit) using a simple pinhole projector. This can be as simple as a piece of paper with a hole poked in it, to a more elaborate and larger projector. Feel free to be creative, as long as you do it safely. Here are some sources for pinhole project ideas: Cosmos Magazine / TransitOfVenus.org / Exploratorium

Binocular/Telescope projection – You can also project a magnified view of the transit by using a pair of binoculars or a small telescope. Here, you want to point the objective lens (the big lens away from the eyepiece) at the Sun, let the light go through the binoculars/telescope and project that image onto a shaded piece of paper. Experiment with different distances until you get everything in focus. Note, that doing this method for a significant amount of time can damage the optics in your binoculars or telescope.

Webcast – If the clouds have you down or the transit occurs during your night time where you live, you can still watch the event unfold from what will certainly be a number of online webcasts. My friends at Cosmoquest will be hosting a Google+ Hangout with various feeds of the transit, and Slooh will make an event out of it as well.

So now that you know how to look, you need to know when and where.

Map showing where the 2012 Venus transit will be visible from.[Map showing where the 2012 Venus transit will be visible from. Source: NASA / Click for larger view.]

Being an amateur astronomer in Alaska (especially along the coast) is the true definition of optimism. There are a lot of clouds year-round, never-ending sunlight during the Summer, and frigidly cold winters that make skygazing a test of tolerance and wills. That said, on those few nights where the clouds have retreated, it’s dark, and above zero… those nights are a-maz-ing. Coincidentally, Alaska is a prime viewing location for the 2012 transit of Venus — in fact, the entire event will be viewable from up here. Ironically, I’ll be out of the state during the transit and will only be able to catch it during a North Dakotan sunset (which sounds pretty, anyhow).

For the most accurate information for your location, there are a handful of resources. There are free iPhone and Android apps for your smartphone. Additionally, if you can find your location on a map this webpage is a fantastic guide. An example of how it varies from place to place:

My home in Kenai, Alaska (June 5th):
Venus crosses into the limb of the Sun at 2:06pm local time. Approximately 20 minutes later, Venus is fully within the disc of the Sun. It will slowly make its way across the face of the Sun over the next 6 hours, reaching the opposite limb at around 8:30pm local time. At 8:48, the show is over with the Sun still high in the sky.

Where I’ll be in North Dakota (June 5th):
The transit will begin at 5:04pm local time. By 8:27pm local time, Venus will be at the center-point of its transit. Around an hour later, the Sun will set, taking the transiting Venus with it.

The bottom line is, due to the duration of the event you should be able to get at least a glimpse of it from anywhere in North America, to a varying degree as shown above. And you’ll definitely want to make every opportunity to see it, because it will quite likely be the last time you have the chance — unless, of course, you plan on being alive for another 105 years (and still have the eyesight to see it!). That’s right, this will not occur again until 2117 — so this is your chance.

Good luck and happy observing!


Upcoming Solar Eclipse

Readers located in the Western United States and East Asia should mark their calendars for this Sunday’s (May 20, 2012) solar eclipse. To some degree, the eclipse should be observable from Texas to Thailand, with certain locales observing an annular eclipse, while others will still get the treat of a partial eclipse.

Track of the May 20, 2012 solar eclipse overlaid on a map.

(Image courtesy of Google and NASA’s Eclipse Web Site)

 Note, you do not need to be on that path in the picture above to see the eclipse. If you’re within that path, you will see an annular eclipse. If you’re North of South of that path, you’ll see a partial eclipse. An annular eclipse is a solar eclipse in which the distance between the Earth and the Moon is great enough that it appears too small to completely block out the Sun. It will look like this:

Eclipse Anular

Photo of a 2005 annular eclipse, as seen from Spain. Photographed by Abel Pardo López and used under a Creative Commons license. Click image for source.

Unlike the case with a total eclipse, where the Moon is closer to Earth and covers the entire Sun (less its corona), do not look directly at an annular eclipse with your naked eyes!

For those of us that will be outside the path of the annular eclipse, many will still be able to see a partial eclipse. Without going too deep into the geometry of an eclipse, be aware that there are basically three types of shadows produced during the event: the umbra, antumbra,  and penumbra. The umbra is the darkest part of the Moon’s shadow, and when it falls upon the Earth it results in a total eclipse. From within the umbra, the Sun is completely blocked out by the Moon. From the vantage point of an observer within the penumbra, the Sun is only partially blocked by the Moon, resulting in a partial eclipse.  Within the antumbra, an observer will see the Moon pass completely between them and the Sun, however its apparent size compared to the Sun will be small enough that it will not completely block out the Sun; an annular eclipse.

The following diagram is a visual demonstration of what I’ve just described:

Diagram showing the different types of solar eclipses.

(Image Credit: University of Tennessee Department of Physics and Astronomy)

“Okay, but I just want to know if I can see it!”

Okay, so you want to know if you’ll be able to see the eclipse, and if so, when should you look? The best and simplest way to find out is to go to NASA’s Eclipse Web Site for this event. From there, you can click on your location on the map and a little window will pop up with details, like so:

Details of the May 20, 2012 solar eclipse for Kenai, Alaska

If you live near Kenai, Alaska (like me) there are your details. Take note that the times are in Coordinated Universal Time (UTC), so you’ll want to adjust accordingly based on your time zone. In my local case the eclipse will begin at around 3:15pm local time (UTC – 9 [AK Time] + 1 [Daylight Savings Time]) and continue for nearly three hours, as the Moon slowly moves across the face of the Sun. For other locations, you’ll find this tool very easy to use.

“What good is knowing when and where an annular eclipse is if I’m not allowed to look at it?!”

I’m glad you asked! By all means, do NOT look at this eclipse with your naked eyes. You will damage them. The visual part of the electromagnetic spectrum is far too beautiful to go damaging your instruments to see it (your eyes!). Fortunately, there are a few simple tools you can use to view it.

The most convenient method is to use cheap cardboard solar-shield glasses made specifically for this purpose. You can buy them online and elsewhere for less than a dollar. (Buy many and share! They’ll also be great for the Venus transit next month, but more on that later!) They look like this:

Solar shield glasses

If you choose to purchase some (there may not be enough time to receive them before Sunday, but there will be plenty of future opportunities to use them as well), I recommend purchasing through a company associated with Astronomers Without Borders, where proceeds will go to benefit others interested in astronomy. Make sure any you use are clearly labeled that they’re safe to view the Sun through.  An alternative to these glasses is to use Number 14 Welders’ Glass, available at welding supply shops.

You can also use a pair of binoculars or a telescope as follows, but make sure that nobody (small children, non-bright adults, pets) looks at the Sun through the eyepieces; it could very well be the last thing they see. To use binoculars or a telescope, you want to project the image onto a piece of shaded white paper. Just align the Sun with the objective lens (not the eyepiece lens) and let the light pass through and onto the piece of paper. An image of the Sun will appear on the paper and, while bright, will be safe to look at.

And finally, if you do not have solar shield glasses, Number 14 Welders’ Glass, binoculars, or a telescope (again, projected onto paper!), you still have another option. You can use a colander, a piece of aluminium foil with a hole punched in it, or even with the aid of a leafy tree. Obviously, if you took a colander outside on a sunny day, let the sunlight shine through it, and reflect onto the ground, you would see the circular dots of light where it was allowed to pass through the holes in the colander, and shade where the solid part of the colander blocked it. If you happen to do this when the Sun doesn’t appear as a solid circular light source (an eclipse), or if something is passing in front of it (a transit), the light in those dots on the ground will show it as well.

Check it out!:

Partial eclipse viewed with the aid of a colander.

(Image Source)

This same effect will work if you poke some holes in aluminium foil, a pizza box, or whatever you might have available. Luckily, you’ll have a bit of time during the eclipse to experiment and see what works best.

Even trees want you to see the eclipse:

The Eclipse Tree, Basildon.

(Image Credit: Picture Esk on Flickr)

So that about covers it. If you have any questions, if I’ve missed anything, or if you believe there is a mistake in my explanations, please leave a comment. I hope you’ll take the opportunity to enjoy this celestial treat and I hope you find people to share the experience with you as well.

Happy observing!


Titanic Star Field Corrected for 100th Anniversary Release

Neil deGrasse TysonI first read this story on April 1st and thought it might possibly be an April Fool’s prank. It turns out it wasn’t.

Director James Cameron is re-releasing his 1997 film Titanic, to commemorate the 100th anniversary of that “unsinkable” ship’s sinking. He intends to change very little from the 1997 release but there is one change being made that makes reporting it fit the theme of this blog: when watching the movie at the theatre during its original release, astrophysicist Neil deGrasse Tyson noticed that the star field in the background of one of the scenes wasn’t accurate. But, instead of just filing that inaccuracy on the shelf with all of the other thousands of scientific errors you’ll find in popular movies and moving on, Neil deGrasse Tyson couldn’t let it go, and on more than one occasion allegedly attempted to alert Mr. Cameron of the error.

Here’s a 2009 video of Tyson describing noticing the mistake in Titanic and his attempts to make Cameron aware of the error (reload page if video doesn’t appear):

Apparently, James Cameron finally got Tyson’s message and told Tyson that if he got him the correct star field, he would include it in the anniversial re-release; Cameron told the UK magazine Culture:

Oh, there is one shot that I fixed. It’s because Neil deGrasse Tyson, who is one of the U.S.’ leading astronomers, sent me quite a snarky email saying that, at that time of year, in that position in the Atlantic in 1912, when Rose is lying on the piece of driftwood and staring up at the stars, that is not the star field she would have seen, and with my reputation as a perfectionist, I should have known that and I should have put the right star field in.

So I said, ‘All right, you son of a b****, send me the right stars for the exact time, 4:20 a.m. on April 15, 1912, and I’ll put it in the movie.’ So that’s the one shot that has been changed.

Neil deGrasse Tyson responded to a question posed by Alan Boyle of the Cosmic Log, who asked him if he Cameron might put his name in the credits:

“If he does, that’s fine,” Tyson told me. “I’m a servant of the public interest and the public’s appetite for information about the universe. I get these calls all the time. … The mere fact that an artist cares about getting the science right, and thereby transmitting that science literacy to the consumers of that art — that’s enough reward for me.”


Flashing the ISS

In case you missed this story from earlier this week, I wanted to point out an interesting historical event.

For years, people have wondered if the astronauts aboard the International Space Station could see a flashlight, or perhaps laser pointer, pointed at it from the Earth’s surface. While it was theoretically possible and tried a number of times, it had never been done successfully… until March 4, 2012.

Texan amateur astronomers of the San Antonio Astronomy Association and the Austin Astronomy Society put together a plan to prove the possibility. On March 4, these amateur astronomers implemented their experiment. They left the urban lights for dark skies (and as importantly, a dark ground from the vantage point of the ISS) at the Lozano Observatory. There, they set up a one-watt blue laser and a pair of bright spotlights, complete with a simple, yet effective, system to strobe the spotlights: people holding wooden boards. Timing had to be calculated precisely for a couple of reasons. Not only did the ISS have to pass their dark location overhead at night, but it had to be such that the ISS had a view of the Earth without the Sun blinding their view; after all, it is the bright sunlight reflecting off of the ISS that makes is so bright and visible to us on Earth.

Their timing, and a few months of planning, paid off. As the ISS came overhead of the anxious amateur astronomers, they flipped on the laser and began alternating the spotlights on-and-off in two-second intervals. ISS Expedition 30 Flight Engineer, Don Pettit, had been involved in the planning of the experiment and had been communicating with the group in the days leading up to the attempt. At the time that the ground crew began their attempts to flash the space station, Pettit was situated in the ISS Cupola, eyes peeled with his camera snapping pictures. The ISS pass was complete within a few minutes, and the group had to anxiously await feedback from Pettit. The next day, their confirmation came.
Image showing the flash experiment from the ISS.

(Click image for larger size / Image Credit: Don Pettit/Fragile Oasis)

Success! According to Keith Little, Marketing Director of the San Antonio Astronomical Association, Don Pettit told him that not only could he see the spotlights, but easily saw the laser by itself!

It’s wonderful when astronauts orbiting the Earth can work together with amateur astronomers to collaborate on experiments such as this, and its icing on the cake when they make history in the process.

For more information about the event, you can view a video of the experiment from the ground here and listen to an episode of 365 Days of Astronomy pertaining to the event.


CleanSpace One

Space — particularly, low Earth orbit — is becoming a messy place. Thousands of satellites (both operational and defunct), spent rockets, and tons of fragments resulting from collisions and erosion of the former, circle our planet. Upwards of 16,000 of these objects larger than 10 centimeters are tracked by the United States Space Surveillance System1. While space, including low Earth orbit, is a vast place, collisions can, and have, happened.
Computer-generated image of tracked orbital debris.

[Click for larger version]
(Image Credit: NASA Orbital Debris Program Office)

In 2009, the US Iridium 33 communications satellite was destroyed when the retired Russian Cosmos 2251 collided with it. Not only did this collision have an effect, albeit minor, on global communications, it resulted in one of the greatest debris generation events to occur in low Earth orbit.2 It’s a compounding problem; debris and defunct satellites collide, creating even more debris.

Fixing Half Of The Problem
There are essentially two problems that we, as a spacefaring civilization, need to address: disposing of existing debris and preventing future debris in the first place. The Swiss Federal Institute of Technology (École polytechnique fédérale de Lausanne (EPFL)), has set its sights set on solving the latter, with their revolutionary satellite, CleanSpace One. The EPFL announced on Wednesday that it planned to develop and launch what is being nicknamed a “janitor satellite” as a trial demonstration of how satellites can be captured from orbit and be re-directed towards Earth’s atmosphere for a fiery disposal. The $10.8-million (USD)3 project will create a single-use satellite, which is expected to capture and de-orbit one of two currently-orbiting Swiss satellites, SwissCube and its cousin Tlsat-1.
Infographic summarizing how CleanSpace One will work.

(Image Credit: EPFL)

Yes, single-use. If you think $10-million+ is a lot of money to experimentally de-orbit a single satellite, I cannot help but to agree with you. However, if you look at CleanSpace One as the first step towards the long-term future of maintaining space, then you start to think that this is an important and worthwhile investment. Due to the increasing problem that space junk is becoming, the costs involved with creating and launching the spacecraft we put into orbit, and the insurance costs to protect that investment once you get it there, I strongly believe that cleaning up space is going to be a lucrative and necessary industry in the not-too-distant future.

Kudos to the EPFL for making this a priority. I hope one day we can look back on CleanSpace One and point to it as being an important first step in keeping the space around our planet tidy!

For more information on CleanSpace One, check out the following video. The satellite capture method is particularly intriguing.


  1. The Air Force Space Surveillance System, which is colloquially known as the “Space Fence”, detects and catalogs objects as small as a baseball, between low Earth orbit all the way to an altitude of 30,000 kilometers (about 18,000 miles).
  2. Second only to the intentional destruction of Fengyun-1C, as part of a Chinese anti-satellite missile test. It created more than an estimated 35,000 pieces of new debris larger than 1 centimeter.
  3. 10-million Swiss francs.

Tortoises In Space: An Homage to Shelled Explorers

Tortoises In Space
Now that I have your attention…

When you think of animals that have been sent to space, what comes to mind? Humans of course, but maybe you also remember the first “higher primate” in space1, Ham the Chimpanzee (or Enos, the first primate to orbit the Earth). Or perhaps the dog Laika — the first animal to orbit the Earth2 — comes to mind. And of course, we’ve sent mice and insects and other organisms into space in the name of research as well.

What probably doesn’t immediately come to mind, however, are tortoises. But tortoises were exactly what the Soviets decided should be among the first animals to circle the Moon.

The Soviet’s Zond (translated: probe) program consisted of two distinct objectives. The first missions, Zond 1, 2, and 3, utilized the 3MV3 planetary probe and were designed to explore Mars and Venus. Zond 1 and 2 failed en route to their respective objective targets, while Zond 3 captured photos from the far side of the Moon on its way out on a Mars trajectory, though the timing wasn’t such that it would encounter the red planet.

Zond 5 Tortoises

Zond 5 Tortoises. Credit: RKK Energia.

Fueled by the “Moon race” between the United States and the Soviets, the following Zond missions employed the Soyuz 7K-L1 spacecraft and were all focused on the Moon. Zond 4 reached a distance of approximately 300,000km (186,411 miles) from the Earth before returning. Its trajectory took it on a course 180-degrees away from the Moon, and there are conflicting stories as to whether or not the Soviets intentionally sent the spacecraft on that course, or if there was a malfunction. It re-entered Earth’s atmosphere out of the Soviet’s control and was remotely detonated at an altitude of 10-15km (6-9 miles), and a couple of hundred kilometers off of the coast of Africa.

Finally, Zond 5 launched on September 14, 1968. Aimed for the Moon, it contained a biological payload including wine flies, meal worms, plants, bacteria, and… two Russian tortoises. Zond 5 took a circumlunar trajectory, which means it looped around the Moon, but didn’t go into multiple orbits around it. Think of a big, lop-sided, figure-eight, with the Earth within a large loop and the Moon within a smaller one. This is very similar to the emergency trajectory that Apollo 13 took, following the disastrous malfunctions that plagued that craft on its way to the Moon.

Circumlunar trajectory of Apollo 13

The circumlunar trajectory of Apollo 13 - Credit: AndrewBuck

The tortoises spent a week in space before splashing down in the Indian Ocean. The tortoises reportedly lost 10% of their body weight during their trip, but remained active and showed no loss of appetite. These tortoises became among the first Earthly lifeforms to complete a lunar flyby and return safely to Earth, proving it possible, and paving the way for future vertebrates such as Neil Armstrong and Buzz Aldrin.

Scientists examining the Zond 5 tortoises.

Scientists examining the Zond 5 tortoises. - Credit: Energia.ru

Zond 5 wasn’t the end of the line for our half-shelled cosmonaut friends; Zond 7 and Zond 8 each carried multiple tortoises. Tortoises then came out of a 5-year retirement to be sent up again, aboard Soyuz 20 in 1975. This time, they were in for the long-haul, spending a total of 90.5 days in space and consequently breaking the record for the longest amount of time an animal had spent in space. Finally, in February of 2010, the Iranian Space Agency sent up their first biological payload into a sub-orbital flight; aboard were two turtles.4,5

So now you know the story of tortoises in space. From being among the first animals to take a trip around the Moon, to breaking records for time in space, tortoises are very much a part of “animaled” spaceflight. Like all of the others that have made Earth’s space programs successful, I tip my hat to the shelled reptiles for their contributions.


  1. Monkeys had gone into space as early as the late 1940’s, though it wasn’t until 1957 when Laika, the dog, became the first animal to orbit the Earth.
  2. And unfortunately, Laika was the first animal to die in orbit, as well.
  3. Third-generation, Mars/Venus
  4. Yes, I’m aware that there is a difference between tortoises and turtles, but the definitions can actually vary depending on which country you’re from. I haven’t been able to find out the specific species of the Testudine Iran sent to space, so they may or may not be tortoises. To be mentioned in this article, I say close enough!
  5. And apparently, at least 64 people are outraged enough by this that they’ve “Liked” a “Save Turtles From Iran’s Space Program” Facebook page.

Celebrate Perihelion

Today, the Earth will be at a point in its orbit around the Sun called perihelion; the point in its orbit about which it is closest to the Sun. Until early July, we’ll be getting further and further away from the Sun, after which point we start getting closer again.

The overall change in distance is quite small, comparatively. Today, we’re approximately 3.1 million miles (just shy of 5 million kilometers) closer to the Sun than we will be in July, at aphelion. When you compare that to an average distance of around 93 miles, you’ll realize why the change in distance is virtually unnoticed by us Earthlings (unless we’re scientists specifically studying the Sun).

Perihelion


A Tale Of One Crater

Dickens Crater

(Dickens crater as imaged from the Messenger spacecraft / Image Source: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

Charles Dickens was the acclaimed English novelist who brought the world such classics as ‘Oliver Twist’, ‘A Christmas Carol’, ‘Great Expectations’, and ‘David Copperfield’, among others (another is alluded to in the title of this post, but you knew that). Widely considered the greatest Victorian period author, he has been honored in many ways throughout the past century-and-a-half.

Dickens might have come to expect many of the honors he received, and those dedicated posthumously, but one that I don’t suspect he ever looked forward to was having a crater on the planet Mercury named after him. Nearly all Mercurian craters are named after artists; writers, painters, composers, etc. Naturally, Dickens wouldn’t be excluded.

The name of the 78km-diameter crater, Dickens, was approved by the International Astronomical Union in 1976, which appears to be the first year they began the unique naming program. (For your general interest, recent “inductees” are a couple of my favorite writers, Khalil Gibran and Rudyard Kipling; having their surnames assigned to craters in 2009 and 2010, respectively.)

For a full list of the currently-291 named Mercurian craters, check out this list.


Ursa Major

The following video is my first real attempt at time-lapse astrophotography. I chose one of my favorite constellations, Ursa Major (best known for containing The Big Dipper). The video shows the motion of the constellation over a 45-minute period.

I live in a small city, so some light pollution factored into the result but overall the night was quite clear. You can clearly make out “The Horse and Rider”, two stars that make up what is typically seen as the second star in The Big Dipper’s handle. The ability to see these two stars, Mizar and Alcor, was used by the Arabs, Romans, and English to test the eye-sight of their warriors.

But there’s even more to Mizar and Alcor than meets the (unaided) eye. Mizar is actually a quadruple system of two binary stars and Alcor is a binary system. Together, they make up sextuple system, as they are all apparently gravitationally bound.

To put it simply, Mizar — which we see as the brighter star, the horse, making up the Horse and Rider — is two sets of two stars orbiting each other. Alcor, is a single set of two stars orbiting each other, and is in turn interacting with the Mizar system. Six stars, dancing together in a cosmic folk dance, appearing to us on Earth as one or two stars (depending on your eyesight).

Additionally, this all goes to show that as much as we think we know about the cosmos, there is so much more out there to discover. Mizar and Alcor have been two of the most observed objects in the night sky for millennia, yet we still continue to unravel more of their magic.

Ursa Major

Ursa Major

Dying A Beautiful Death

The red giant AFGL 3068 is dying a beautiful death. Like all red giants, as they expand they spew their outer layers into space in a spherical shape. What’s unique about AFGL3068 however, is that it’s actually a binary star — two stars orbiting each other. Due to the orbits of the two stars, the material that’s ejected isn’t able to expand into a sphere, but in this amazingly perfect (and awesomely huge at 3 trillion kilometers!) spiral.

Look for yourself:

AFGL 3068

AFGL 3068

(Click image to embiggerify)

Thanks Hubble!