Friday, July 18, 2008

Carnival of Space #63

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This weeks Carnival can be found over at the Angry Astronomer.

Hut 33 and Astronomy

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Hut 33 (and here) is a BBC radio comedy set in 1941 at the super secret code breaking organization at Bletchley Park. Although fictional, the code breakers of the Hut are brilliant and occasionally quirky much like the real people who worked there. This group is a bit more dysfunctional.

In the inaugural episode of Hut 33, a young and naive Gordon (the prodigy) found himself on a Valentines day date with Minka. A very nervous Gordon seeks advice on this sensitive topic. On Mrs. Best's advice to talk about the stars and her eyes, Gordon prepares himself.

Just before the date, Archie asks Gordon about how he's prepared for the date. Gordon indicates he has lots of material about the stars and eyes ... "They're created through an equilibrium between the compressional force of gravity and the outward pressure of radiation ...". Panic and hilarity ensue.

In later episodes we find out Gordon was a Cub Scout. See "Hut 33 finds Mowgli" and "Hut 33 returns with more Scouting connections".

Great news, Hut 33 was just approved for a third series.

Update: Hut 33 Series 1 is being replayed on BBC4, see here. Episode 1 is set for August 5th @ 6:30pm. Episode 2 will play on the 12th. Presumably episodes will play weekly. You can catch up for up to a week on "Listen Again" off the series page or here.

Thursday, July 10, 2008

Carnival of Space #62 - The Image Extravaganza! @ Space Disco

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A new Carnival of Space is up over at Dave Mosher's Discovery’s Space Blog "Space Disco". This week's Carnival looks at space images.

Check it out at Carnival of Space #62 - The Image Extravaganza!

Saturday, July 5, 2008

Using feeds to speed up your browsing

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Some of you may wonder how much time I spend looking at blogs and web pages to find gems like this. The truth is far less than you may think.

In an earlier article, I wrote about using web feeds for blog (and news) headlines. So rather than reading huge amounts of web pages, I can just look at my feeds and see just the headlines once or twice a day. That lets me read or bookmark what looks interesting and save a lot of time.

If you read the article on security excuses, you may wonder how I found a web page on a site I've never looked at before. I could have found a page that referred to another page, but I didn't. One of the blog feeds I subscribe to is the Security Bloggers Network which aggregates blog headlines from security bloggers. The only down side of this is that with many authors there's a lot of variation in what style and content that may not be acceptable to everyone.

Top 10 excuses for not securing your computer

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I came across a good blog article describing the top 10 excuses people use for failing to secure their computers, here. It's actually a repost of another article.

This is the first time I've actually read this persons blog and I can't say much about their style and content other than this was a good article worth pointing to. A quick look shows posts about malware, viruses, security, and cleaning up infected computers.

Thursday, July 3, 2008

Carnival of Space #61: Tunguska Edition

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Welcome everyone to the 61st Carnival of Space. I am delighted to be your host for this edition of the Carnival marking the 100th Anniversary of the Tunguska Event.

As this is my first time hosting, I also want to welcome you to Mang's Bat Page where a Cub Scout leader takes a strong interest in astronomy, space exploration, cryptography, and why things fail - all hopefully with a Scouting flavour. If you want to know about the name see Why Mang?

I encourage you all to leave comments. Normally this site is moderated, but for the next week I've opened things up. Please keep all comments PG as I have youth readers and I don't want to delete comments (I have no ability to edit them).
Thanks to my friend Richard for the Tesla death ray photo
and not electrocuting anyone in the process.
(BTW. the spark to the grounding rod on the left was over 8 feet!)
Just Kidding Nikola
So let's explore the real cause of the Tunguska blast ...

Well perhaps not the real cause. So without further ado ... lets get this party started.

First our non-Tunguska submissions ...

From Earth to the Moon and Mars

At Nextbigfuture, Brian Wang reports that the Blackswift Hypersonic program may not get fully funded for the $750 million that it needs, but the program has a lot of interesting technology and innovations for greater efficiency. Read more about The technology of the hypersonic Falcon HTV-3X.

From Centauri Dreams, Paul Gilster, sends us NanoSail-D: Solar Sail Deployment Planned which looks at the upcoming attempt to launch a small solar sail for deployment experiments in space on a modest budget.

At A Babe in the Universe, Louise Riofrio, gives us a peek at Altair. Perhaps the next lunar lander by 2019. And possibly a large step towards a moon base.

From Altair VI, David Portree sends us articles on two early US studies: the first Mars sample return study (1967) and the first lunar outpost resupply study (1992). There are some nice Gemini pics too.

And at Colony Worlds, Darnell Clayton considers that future Martian colonists may need to rely on "solar steam power" technology in Solar Steam To Power Martian Cities? Oh, and there's a video too.

Ian O'Neill at Astroengine considers future Mars colonists in Watch out Phoenix! Don't Scratch the CD! I guess, the receipt will be the least of their problems returning it.

Update: Emily at the Planetary Society has an update on the activities of the Phoenix mission at Mars, up to sol 36. This update contains some amazing amateur-produced panoramas, and some more troubling news about TEGA. Read more in Phoenix sol 36 update: Scraping in Wonderland, next steps for TEGA.

Science!

Over at Starts with a Bang!, Ethan Siegel announces the publication of a paper about Dark Matter in Our Solar System. Congratulations Ethan!

Mike Simonsen at Simostronomy looks at Dusty TOADs a rare class of White Dwarves with a bit of a temper. Please pass the sun screen folks.

From the Orbiting Frog, Rob sends us plans on how to make your own spectrometer! (with everyday household items no less). Pity, for once his science experiments don't involve food or drink. It's okay Rob, the Cub Scouts will forgive you :)

Entertainment, Photography, and Art

Moving down-under, Ian Musgrave at Astroblog has some photos and animation of The ISS, Mars, Saturn and Crux. (Hey Ian, I could use some southern feedback on Navigation Without Compass or GPS).

At Out of the Cradle, Ken Murphy our Lunar Librarian, provides a nice of overview and update on Japanese space comics (Manga) and cartoons (Anime).

Music of the Spheres discusses the new Pixar movie WALL-E. Should we fear science and technology, or embrace it? The answer from WALL-E the robot in 2700: yes! Read more at WALL-E: The Trash Route to Space Colonies.

At the Martian Chronicles, Ryan Anderson looks at the new Astrobiology related computer game Spore and considers some of the science in the game.

Insight

At Cumbrian Sky, Stuart Atkinson takes a personal reflection on his enthusiasm for astronomy, outreach, and those who do and don't get it in Woah... I know Astronomy.... Well worth a read.

Over at Artsnova Art Gallery, Jim Plaxco takes on the The Religion of the Face on Mars and talks about why people want to see a face.

Rob from Orbiting Frog nominated Stuart's article at the Astronomy Blog titled Changes to ESA?

Bruce Cordell at 21st Century Waves writes "10 Reasons Why China is Good for Space" and looks at some economic reasons why the decade from 2015 will be interesting for space exploration and development.

From Free Space blogs at Discovery News, Irene Klotz writes about Twittering spacecraft and blogs. Phoenix twitters. And now, apparently, so does her blog.

History & Conservation

Robert Pearlman at collectSPACE has contributed an editorial to Discovery Channel's space blogs about saving the bricks recently blasted out of the Pad 39A flame trench in If these Walls could Talk. I'd sure like to buy one.

Update: Todd Flowerday at Catholic Sensibility reflects on Satellite Imagination: the Herschel years. It seems a lot of early astronomers had some rather large blind spots. But not Herschel.

Tunguska

Yikes Fraser! I was sure there would be a raft of articles submitted on Tunguska. So following the motto of being prepared, I took the liberty of writing my own. Please enjoy reading Tunguska's Legacy.

I'd also like to nominate the following articles.
Wrap-up

Congratulations to the Bad Astronomer on his move to Discovery blogs.

Thanks to Fraser for letting me fill in this week as the Carnival guest host.

Finally, thanks to everyone for reading. Please take some time and explore the Bat Page, fill in the guest book or contact me.

Update: Oops and I almost forgot NEOSSat

Music of the Spheres posted Don't Blame Canada and Universe Today posted Canada to build World's First Asteroid-hunting Satellite.

Until next week ...
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Carnival of Space Index @ Universe Today

Previous: Carnival of Space No. 60 @ Slacker Astronomy
Next: Carnival of Space #62 - The Image Extravaganza! @ Space Disco

Tuesday, July 1, 2008

Tunguska's Legacy

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One hundred years ago today[1] there was a very large explosion over the lower Tunguska river in Siberia[2]. Known as the Tunguska event, the explosion is estimated to have been equivalent to a blast of at least 5 million tons of TNT and felled over 80 million trees. The cause was a mystery for decades. Evidence of Nickel and Iridium have been found near the site which supports theories of a meteor impact or air burst. Eyewitnesses told their stories to investigators years later. To date, no crater or fragments have been found.

Unaware of our dangerous neighbourhood

For millennia people have lived in ignorance of the space around our planet. Comets were thought to be bad omens and portenders of catastrophe. Yet, asteroids and meteoroids whizzed by us unnoticed. What we do notice are the frequent meteor showers caused by small particles burning up in the atmosphere and occasional fireballs and small explosions caused by larger rocks.

Very occasionally one of these larger rocks would get too close and explode low in the atmosphere or impact the planet leaving devastation and craters. And on very rare occasions there are devastating explosions. The best known of these was about 65 million years ago and is credited with killing off the dinosaurs.

It has only been very recently that we have recognized impact sites for what they are. The earth, weather, and time are very good at obliterating the evidence. Even the origin of the famous Barringer Crater in Arizona was controversial up until 1960! And the Barringer crater looks like it was moved from the moon to the dessert.

Tunguska didn't leave a crater and wasn't investigated until years later. It certainly isn't as obvious as Barringer or other sites. While the meteor explosion is the leading theory, there is an alternate one based on the idea of a explosive volcanic gases (a micro-Verneshot). There are also a large number of bizarre and wild ideas as to its' origin.

The legacy of Tunguska and other impacts has been to raise awareness amongst scientists, policy makers, and the public that impacts from meteors, comets, and asteroids do happen and that action can and should be taken to protect people and the environment.

What can we Do?

If we are unlucky enough to have a really large rock bearing down on us and about to strike then there is not much we can do. But these are exceptionally rare events and we should have lots of time to act. It's is certainly in our best interest to be prepared to do something to prevent this kind of event if we can.

1. Don't Panic!

While the thought of multi-megaton impacts sounds pretty scary, its important not to over react. How does this all stack up?
  • Small impacts and near misses happen all the time. [3][4]
  • Big impacts, like Tunguska, are uncommon. When they do happen, they are likely to be in remote areas or over oceans.
  • Really massive impacts, like the one the killed off the dinosaurs, are incredibly rare. So rare, it's almost impossible to get a real feeling for the time-scale even though we can measure it.
It turns out that we should be able to something. Quite a lot actually. Now if you're thinking of movies like Armageddon or Deep Impact, reality is a bit different.

2. Size the Risk

Consider, if Tunguska sized events happen once every hundred years, then there will have been more that 1/2 million of them since the dinosaurs died out. If they happened every 1000 years, that's still over 50,000 strikes. There is no historical evidence indicating similar strikes in written history[5] which covers the last 6000 years or so.

How do we do this? By studying both the sky and the Earth.
  • Geologists have been getting very good at finding impact sites on Earth. There is a online impact database, here (a Canadian contribution). This can tell us a lot about what reached the ground.
  • There are all sky camera networks to detect fireballs from meteors, here and here.
  • Recent work has detected Explosions on the Moon which can tell us a bit about how dangerous our neighbourhood is by watching the impact on a body unprotected by an atmosphere.
  • The US Congress has mandated and funded an effort to detect, catalogue, and track any really catastrophically dangerous asteroids. This effort is also detecting a lot of smaller rocks including Tunguska sized meteoroids, as well as comets.
  • Canada is launching a micro-satellite called Neossat to detect and help track Near Earth Objects. See Don't Blame Canada.
These efforts will not only let us size the risk, but they will also give us advance warning.

3. Prepare for Action

Advance warning will let us focus on the dangerous rocks and give us the years needed to prepare. It will also give us techniques that will be more effective and far less dramatic than throwing nuclear weapons around.

Research is already underway around the world on things that can be done. And a broad set of tools is being proposed to deal with the risk. They range from
  • radio tagging an asteroid to better understand it's orbit
  • painting one so that years of Sunlight alters its orbit for us.
  • nudging one using a space tug
It turns out that there are a few rocks of concern.
  • 99942 Apophis is about 270 m and will come very close in 2029 with a possible impact in 2036. As measurements have improved the likelihood of an impact has been reduced and is now considered unlikely
  • 1950DA is about 1.4 km and is a risk to impact in the year 2880
  • 2007 VK184 is a 130 m rock of most concern right now with a chance of impact in 2048
Even with this new rock on the block, Apophis as the poster child bad boy has driven planning.
  • The Planetary Society's Apophis competition, here.
  • B612 who what to alter an asteroids orbit by 2015, here.*
  • US Bill supporting a mission to radio tag Apophis, here.*
  • A Russian project to tag Apophis, here.*
Thanks to other bloggers and their readers for some of the links* above.

Some other Tunguska anniversary posts

Oh, and back at Tunguska

An Italian research team may have found evidence of an impact body that survived the air burst, here.

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[1] The explosion occurred at 7:14am local time on June 17th, 1908 in the Julian Calendar in use there at the time. This was June 30th on western calendars. Adjusting for time zones the blast was at 7:14PM EST June 29th. For a versatile date converter capable of converting between many calendars see here. My original notes for this were based on an old Wikipedia entry with an incorrect date and was going to publish this on June 30th on the Julian calendar - so I'm now late beaten to the punch :(
[2] The location, given as 60°55' N, 101°57'E, is pretty remote as you can see here.
[3] I've written about asteroid near misses before, here.
[4] I've also written about fear mongers before, here.
[5] There is some speculation that the Biblical tale of Lot's wife may relate to such a strike. But it seems designed to sell a book. See here, and here. A very strong critique (with some mild bad language) here. See [4] above.