02 October 2013

World Space Week 2013

This Friday marks the beginning of World Space Week. What is World Space Week, and why does it start on a Friday?
[World Space Week] is an international celebration of science and technology, and their contribution to the betterment of the human condition. The United Nations General Assembly declared in 1999 that World Space Week will be held each year from October 4-10. These dates commemorate two events:
  • October 4, 1957: Launch of the first human-made Earth satellite, Sputnik 1, thus opening the way for space exploration
  • October 10, 1967:  The signing of the Treaty on Principles Governing the Activites of States in the Exploration and Peaceful Uses of Outer Space, including the Moon and Other Celestial Bodies.
World Space Week 2013 is all about what many consider the Next Frontier: the planet Mars. Humanity is quickly conquering this new frontier. Mars Curiosity is the largest rover ever brought to another planet, discovering new features of the Red Planet every day.
This World Space Week, look for events happening in your area, and make a special effort to talk about Mars or any kind of space exploration with friends and colleagues. You can also share videos and articles about space exploration via Facebook and Twitter. Watch our Twitter feed and Facebook page to find posts that you can share.

All links URLs:
http://www.worldspaceweek.org/wsw/
http://www.worldspaceweek.org/wsw/index.php?option=com_content&view=article&id=65&Itemid=3
http://www.worldspaceweek.org/wsw/index.php?option=com_content&view=article&id=145&Itemid=167
http://www.worldspaceweek.org/wsw/index.php?option=com_content&view=article&id=98&Itemid=166

20 September 2013

Live Session Today

Today's live session will be run through Blackboard. Use this link:

http://elluminate.oia.arizona.edu/scheduleMeetingnonetid.php?sessionId=1954233

Live sessions on Udemy seem to still be not working. Again, sorry to have had to cancel last minute on Tuesday; we know some of you on the other side of the globe have to stay up late or get up early to join us. We're addressing the problem with Udemy, but we should be able to use Blackboard in the mean time.

16 August 2013

How About Binoculars?

We had a question in our last live session about binoculars. Since many of our students may be interested in ways to observe the night sky, I thought I'd make a post about what kind of binoculars are best for this. Binoculars are a great tool for amateur astronomers. They cost less than telescopes, they're easy to tote around wherever you go to observe, and they reveal a lot of the sky that is not visible to the naked eye.

The 2 most important features of binoculars are the magnification, and the objective aperture. When shopping for binoculars, you'll find they're all designated by a set of numbers; for example, 20x60. The first number is the magnification. The second, is the objective aperture. A 20x60 pair of binoculars will magnify what you're looking at 20 times, and each of the big, outer lenses will measure 60 millimeters across.

For nighttime use, you'll need a pair of binoculars with a large objective aperture. The bigger those outer lenses are, the more light you'll be gathering, and the brighter dim objects in the sky will appear. I recommend picking out a pair with a lens diameter of 50 or more.

However, it is perhaps, more important that you get the right magnification. For handheld use, you can't use a magnification higher than 20. No matter how steady your hands are, they won't be steady enough to allow you to keep the object you're looking at in your field of view if it's magnified too much. Every tiny little movement of your hand will also be magnified. Unless you'll be getting a stand for your binoculars, keep the magnification between 10 and 15. Generally, for astronomy, magnification is not ever as important as light gathering power.

Therefore, an ideal pair of binoculars for observing the night sky might be 15x70.

And what will you see? Many star cluster that are invisible, or barely visible to the naked eye are easily seen through a pair of binoculars. The best star clusters to try to find are the one's in Messier's catalogue. Other objects that are great to observe with binoculars, some of which are also listed in Messier's catalogue, include, the Andromeda Galaxy; the Orion Nebula; Coma Berenices; Saturn's rings; the phases of Venus; the Galilean moons of Jupiter; the moon; and, occasionally, comets.

The more you observe the more you'll find to look at. If you have a lot of experience with binoculars, and have any tips or recommendations, please leave comments and share your knowledge.

25 July 2013

Artist's Rendition: Titan

Saturn has over 60 moons—that we know of, but one of the most interesting is it's largest moon: Titan. Titan has lakes and rivers, just like the Earth. However, it's far too cold on Titan for water to exist in a liquid state. In fact, water is not only hard as rock on Titan, many of Titan's rocks and mountains are made of water ice. So, what flows in the rivers, and fills the lakes on Titan? On Earth it's a gas, known as natural gas: methane. Titan has a methane cycle very similar to Earth's water cycle. Liquid methane evaporates from rivers and lakes, forms methane clouds, and falls back to the ground as methane rain.

The Denver Museum of Nature & Science has developed a special program for learning about what Titan is like at it's surface, but it's not in a way you might expect. There's no series of slides with bullet points containing facts. Instead, it's an art lesson. Yes, an art lesson. While learning the basics of how to draw mountains, clouds, and and other features common on both Earth and Titan, you can learn about their composition, and why they occur on Titan.

Art Station Titan Show from DMNS on Vimeo.

Here's a video of Eddie Goldstein taking you through the Titan art process. All you need is a sheet of paper and a pencil, but if you have an orange paper, and both a dark and light writing utensil, that will work best. And don't worry if you're no artist. My Titan art came out better than I expected, and yours will too.

Titan art by Carmen Austin

08 July 2013

Still Upset About Pluto

Pluto's done it again. That little rock located millions of miles away seems to have a knack for causing drama down here on Earth.



The first dwarf planet ever discovered in our solar system, astronomers made the mistake of referring to Pluto as simply a planet. By the 90's astronomers were beginning to realize there might be a lot of other objects in our solar system that were similar in size to Pluto. Sure enough, in 2003, what later came to be known as Eris was discovered.

Dwarf planet Eris is actually more massive than Pluto, and has at least one satellite to boot. Eris and Pluto are both trans-neptunian objects, meaning, their location in our solar system is beyond Neptune's orbit.

When the International Astronomical Union (IAU) decided it was time to devise a new classification for Pluto and Eris and the other dwarf planets being discovered, there was an uproar. In 2006 the IAU voted on resolution B5. The definition of a planet became:
A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
76 years after its discovery in 1930, Pluto was officially bumped out of the planet category. Earthlings everywhere were outraged.

Now another 7 years later, the IAU has upset Pluto lovers again, at least, Pluto lovers who also love Star Trek. It was recently discovered that Pluto has not only 3 moons, but 5. Pluto's largest moon Charon was discovered in 1978. Nix and Hydra were discovered in 2005. In 2011 and 2012, 2 more moons, smaller than any of the others, were discovered.

The IAU has the final say when it comes to naming solar system objects, but it was decided a public vote might spark some interest in in planetary science.

William Shatner led a movement to name one of the moons Vulcan. Many Trekkies were on board with the idea, and in the end, the name Vulcan had the most votes. Unfortunately the IAU wasn't on board.
The term “vulcanoid” remains attached to any asteroid existing inside the orbit of Mercury, and the name Vulcan could not be accepted for one of Pluto’s satellites (also, Vulcan does not fit into the underworld mythological scheme).
And so, instead, the newly discovered moons have been name Styx and Kerberos. William Shatner tweeted his disappointment.
 Read the full press release from the IAU here

Pluto, no one may be able to say you're their favorite planet anymore, but clearly, you're our favorite dwarf planet.

25 June 2013

A Tweet From Dr. Mark Clampin, Webb Telescope Observatory Project Scientist

When I logged on to Twitter today, I noticed that NASA was holding a tweet-chat with Dr. Mark Clampin, the Webb Telescope Observatory Project Scientist via the JWST Twitter account, @NASAWebbTelescp. There were only about 20 minutes left to ask questions, so I scrambled to find a question one of our students had asked in a live session.


Did you know all of our live sessions are recorded and uploaded to YouTube, so even if you miss one, you can watch it later, at your convenience? And did you know that in the description of each live session video you will find every question asked during that live session?
 

Make sure the About tab is selected, and click Show More to see all the questions asked in that video. Hopefully this makes browsing through live session recordings to find the topics you're interested in quick and painless.

I found a question Errol asked during the second live session. He asked, "It is exciting to find exoplanets, but what is the real value or significance of finding and studying them?" and quickly tweeted.

And Dr. Clampin replied!
Thanks for taking a moment to answer our questions, Dr. Clampin, and thanks for all the work you do to make JWST possible. We're all big fans over hear at the ASOTA MOOC.

To see the rest of the Q&A from this tweet-chat, visit the @NASAWebbTelescp page or search Twitter for #JWSTexoplanet.

Here is the live session video in which Errol's question is asked. It's the last question of the session. To skip straight to it, click here.



18 June 2013

Ready for Launch: NASA's IRIS Spacecraft

The photosphere is the visible surface of the sun, sort of like the Earth's surface. It's what we see when we observe the sun in visible light. It's where you find sunspots. The temperature at the photosphere is 6,000 Kelvin (5,700°C, 10,300°F) The layers of the sun above the photosphere are called the solar atmosphere.

On top of the photosphere is the chromosphere. The chromosphere has a very small density—it's actually less dense than the Earth's atmosphere. A funny thing starts to happen as you travel out of the sun through the chromosphere. The temperature drops at first, by a couple thousand K, and then increases. The outer edge of the chromosphere is 35,000K.

The next layer of the sun is called the transition region. The solar transition region is the layer of solar atmosphere in between the chromosphere and the corona. It's called the transition region, because the solar matter acts differently above and below. One example of this, is the temperature. The temperature of the sun skyrockets through the transition region. Remember, the temperature of the photosphere is 6,000K? The temperature of the corona is closer to that of the interior of the sun. The internal temperature of the sun is somewhere around 15,700,000K. The temperature of the sun's corona is 5,000,000K, and can even exceed 15,000,000K.

NASA's IRIS spacecraft will study the sun's chromosphere and corona. This will help us better understand the solar transition region, and how the sun's photosphere and chromosphere interact with the corona.


Here's the mission statement from NASA:
Understanding the interface between the photosphere and corona remains a fundamental challenge in solar and heliospheric science. The Interface Region Imaging Spectrograph (IRIS) mission opens a window of discovery into this crucial region by tracing the flow of energy and plasma through the chromosphere and transition region into the corona using spectrometry and imaging. IRIS is designed to provide significant new information to increase our understanding of energy transport into the corona and solar wind and provide an archetype for all stellar atmospheres. The unique instrument capabilities, coupled with state of the art 3-D modeling, will fill a large gap in our knowledge of this dynamic region of the solar atmosphere. The mission will extend the scientific output of existing heliophysics spacecraft that follow the effects of energy release processes from the sun to Earth.

IRIS will launch on June 26th, at 7:27PM PDT/10:27PM EDT. Find out more about IRIS at www.nasa.gov/iris.

03 June 2013

Teach Astronomy YouTube Lectures

Are you missing the weekly lectures from Chris? Did you know there's a whole YouTube Channel with over 30 hours of Chris lecturing on Astronomy? Created for TeachAstronomy.com, the Teach Astronomy YouTube channel consists of 29 playlists, each containing about 35 topical 1-3 minute videos. A great way to browse through them is on TeachAstronomy.com, using the wikimap. We hope you'll take a look through them, and keep them in mind for the next time you've got an astronomy question on your mind.

Here are the 5 most watched videos from the Teach Astronomy YouTube channel

22 May 2013

June and July Live Sessions

We'd like to continue holding live sessions, for at least 2 or 3 months, but the instructional team is doing a lot of traveling during the summer months, so we'll only have about 2 live sessions per month. We will definitely be having one tomorrow at 11AM MST/PDT (in 21.5 hours!), and we've tentatively picked some days for June and July.

These dates and times are tentative and may change! But here they are—dates for the next live sessions:
Thursday May 23rd, 11AM MST/PDT (6PM GMT/UTC)
Monday June 3rd, 11AM MST/PDT (6PM GMT/UTC)
Wednesday June 26th, 11AM MST/PDT (6PM GMT/UTC)
Thursday July 19th, 11AM MST/PDT (6PM GMT/UTC)
Some day the last week of July/first week of August

If you miss a live session, post your questions on Udemy. Chris will continue to answer questions posted to our Udemy page.

09 May 2013

LHC on The Daily Show

One of our lectures from Section 7, the section on Cosmology, featured a clip from The Daily Show with Jon Stewart. Watch the whole segment here.


And if you enjoyed that, you'd probably also enjoy this segment about the size of the Andromeda Galaxy from the Colbert Report.

Citizen Science

Did you enjoy doing citizen science through Zooniverse? Zooniverse has 7 citizen science astronomy projects, and they're not the only site perpetuating astronomy citizen science.

Zooniverse


Cosmoquest


GLOBE at Night


SETI@home

And here's an even bigger list compiled by The Planetary Society. We hope you'll continue to contribute to citizen science.

04 April 2013

First ASOTA Live Q&A This Friday


Hello everyone!

Professor Chris Impey will be hosting a live online discussion for Astronomy: State of the Art on Friday, April 5th from 3pm to 4pm PDT (Pacific Daylight Time).

Although he will be interacting with students live during the session, we realize not everyone will be able to attend, and we invite you to submit questions ahead of time.  This will also help us keep things organized, and to prepare ahead of time in case of network issues that could make asking questions in the session more difficult.  Please send questions to us via Twitter to @AstronomySOTA or through email to: AstronomySOTA@gmail.com.

There are 3 (three) ways to participate in the live discussion:

1) You can join us on Udemy using their LIVE SESSION tool (you will see the link on the course page).

2) You can join us using the Blackboard Collaborate tool through the University of Arizona.  You will need to install the most recent version of JAVA for this to work.  Simply click on the following link, download the file, and click on it when you have finished downloading (if you get syntax errors, just click OK and it will still work just fine).  The Blackboard Link is: (http://elluminate.oia.arizona.edu/scheduleMeetingnonetid.php?sessionId=1518395)

3) Watch the broadcast on Google+.  We will broadcast the session live in a Google Hangout and the video will be available afterwards on YouTube for those of you who were unable to join us live.  There is currently no good way for us to use G+ to interact with more than 15 people at a time, so for now this tool will be used for broadcasting and recording (YES, you will be able to watch it, even without a Google+ account, and it will be available on our Google+ page and on YouTube after the session has ended).  To watch the broadcast, click on the following URL for our Google+ page. (https://plus.google.com/u/0/110438101511252202485/posts)

We’re looking forward to meeting you!

29 March 2013

Week 1

We were thrilled to see over 1,000 students enrolled in the course by the end of day one! Thanks for joining us. We hit 1,200 students later in the week, making us larger than any other University of Arizona class ever.

Week one was all about observing, and the technological advancements that allow us to build bigger and bigger telescopes.

Chris interviewed:
You can listen to the interviews here:



Isn't the work they do at the Mirror Lab incredible? If you're ever in Tucson, stop by the University of Arizona campus and get a tour! If you're lucky, they'll be cooking up one of the 7 mirrors for the Giant Magellan Telescope (GMT) while you're there. You'll be able to see the oven spinning, and feel the heat from it. And they're almost always polishing one of the GMT mirrors or the primary mirror of what will be the Large Synoptic Survey Telescope (LSST).





Many of you participated in the assignment for this first week of class.  Our gmail inbox and Facebook page were full of awe inspiring astronomical images. We'd like to share a few of them with everyone here.

Credit: HiRISE, MRO, LPL (U. Arizona), NASA



Mandy Shaw shared this image of Mars via Facebook. 
One of my favorite astronomical images is of the pinkish, frost-covered sands on Mars. Captured by the Reconnaissance Orbiter in 2008, the image seems to show trees! But, in fact, they are not trees (and cast no shadows), but instead are streaks of cascading, frost-free sands.



NASA Voyager Mission






Rick Mutton shared this image of Jupiter via Facebook.
This image holds a special place for me - it was taken by Voyager 1 in 1979, when I was in grade 8 and really got me interested in astronomy and science.








Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team















Finally, Zachary Zalneraitis (@zzalnera) shared this image of the Hubble Deep Field with us via Twitter.
What exists in the darkness of Hubble XDF amazes me.

Thanks for all of your submissions! Many of you shared images you've taken yourself. We are very impressed by your work. If you're an astrophotographer, and you'd like us to include you in a blog post about students in this class who do astrophotography, email astronomysota@gmail.com with information about you and where we can find your work online, or one of your favorite images.

Next week we'll be traveling out beyond Earth, into our solar system. Lectures will cover some of the neighboring worlds we are very interested in exploring. We'll talk about the past, the present, and the future of Mars exploration, as well as where we've found water in our solar system.

If you really enjoyed the observing and telescopes week, here's one last video about a great telescope called SOFIA.



26 March 2013

Welcome to the class!


I'm excited that we are underway and there are over 800 of you, spread around the U.S. and the world. The first week of materials on telescopes and detectors are posted:
  • An overview video
  • .pdf slides on all topics
  • Video mini-lectures on 7 of those topics (the "cutting edge" ones)
  • An activity, and
  • A simple quiz

As we start I'd like to ask each of you to register on the Teach Astronomy web site (if you pre-registered on that site, you don't need to do this). The minimal information you provide will be kept secure and only used in relation to astronomy and this course. I need this to be able to communicate with you directly (which is not possible in Udemy), and to share additional instructional resources and social media conversations about the course (neither of which can be hosted by Udemy). I hope you enjoy the information and the experience. Chris I.