A Ghostly Apparition for Halloween!

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Known unofficially as the “Ghost Nebula” or “Ira’s Ghost”, this vast cloud of interstellar dust harbors an incubator for new stars. Discovered in 1983 by the IRAS satellite (InfraRed Astronomical Satellite), it is officially known as IRAS 05437+2502 (Ira’s Ghost sounds a lot spookier!). This image was taken in visible light by the Hubble Space telescope and released in June 2010.

Located in the constellation of Taurus, the nebula covers about 1/18th the size of the full Moon. The bright inverted “V” seen in the upper left of the nebula is a rather perplexing structure. One theory is that it may have been formed by a large star that was ejected from the nebula at an extremely high speed. For more information about Ira’s Ghost, check out the Hubble site.

Enjoy your Halloween, and be very glad that Ira’s Ghost is far, far away!

Till next time,

RC Davison

Is Space Our Final Frontier?

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“Space, the final frontier.” Simple words spoken by Captain Kirk, of the starship Enterprise, but ones that create a sense of excitement and wonder.

But, is “space” our final frontier? With the billions upon billions of galaxies out there, containing an uncountable number of stars and an unimaginable number of planets, is it our last frontier?

Hubble Ultra Deep Field - Image Courtesy of NASA

There is something about space…so vast, so enigmatic, so alluring. I have long gazed at the stars and felt that there is so much out there to discover and learn about—things that would just boggle our minds. And, we already see it today with the amazing image from the space telescopes like Hubble and Spitzer and terrestrial observatories like Keck and the European Southern Observatory’s Very Large Telescope. It may truly be the final frontier. But, for us to be out among the stars, and, if you can imagine it, out among the galaxies, we will have to conquer hurdles and challenges that will include understanding how our Universe works. More importantly, we need to understand how we work, as biological entities, as well as cultural and societal beings, because we will never have the strength and dedication to reach for the stars if we can not respect, have consideration for, and cooperate with one another.

Thinking about it a bit more, maybe that is our final frontier. Not “space” as Gene Roddenberry so simply stated way back in 1966 when Star Trek first beamed into our homes on our televisions. Maybe he was really speaking of a frontier more subtle, more challenging than traveling to the stars. Maybe that frontier is simply people working together—united—where our challenges are no longer with each other but come from beyond the humble abode we call Earth.

I’m afraid that once we do step out into the cosmos, beyond the comfort of our blue planet and yellow sun, and travel to these other stars, solar systems and planets to study them up close, each will offer more unknowns that will push the boundary of our final frontier. Undoubtedly there will be more things discovered that will have us scratching our heads and wondering just how does that work. That bewilderment may very well come more from the biology we find rather than the new physics we might discover. And, that doesn’t even address the issues of us trying to comprehend alien cultures and societies that have absolutely no parallel to what we’ve experienced on Earth!

So, where does the boundary exist to define the final frontier? Unfortunately, I think it will be a boundary we will approach asymptotically—always getting closer but never really reaching it—and I can’t wait! There’s so much to discover!

Hopefully, some food for thought; so think about it, talk about it, comment on it—I’d be happy to hear your views on our final frontier.

Till next time,

RC Davison

Planetary System Found Around a Binary Star System

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Some said it wouldn’t be possible, but Kepler has revealed a binary star system that has a planet (Kepler-16b) orbiting around it.  To some this is reminiscent of Tatooine, Luke Skywalker’s home planet in the “Star Wars” saga.

Artist's concept of planet orbiting the binary star system - Kepler-16b Image courtesy of NASA

This planet, which is about the size of Saturn, cold, possibly gaseous and rocky and orbits around the pair of stars in 229 days.  It also lies outside the habitable zone of these stars, which is the zone around a star that water would exit in a liquid state.  The two stars are smaller than the Sun, being about 69% and 20% the mass of our star.

Here’s a nice video showing the dynamics of this unique system and provides some great background information.


 

To say that such a planetary system could not exist was so very short sighted.  We have just begun to uncover the wonders of this Universe we live in.  I can only imagine what other wonders are out there that someone has stated emphatically would be impossible.  The possibilities are endless!

Till next time,

RC Davison

Blackness in the Void

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Welcome to the first posting at ORBITAL MANEUVERS new blog site!

I will be moving the posts from the old site shortly, but until then the original site is still available.  This move will allow more flexibility in the blog posts.  Now on to the good stuff!

Black as Coal

In the novel, ORBITAL MANEUVERS, the asteroid that impacts Earth escaped detection for of a number of reasons, but one of the main reasons is that it was composed of a material that was blacker than black — it reflected almost no light.  How black is that?

The scientific term used to quantify this blackness is albedo.  It is simply the ratio of the amount of incident light on an object to the amount of light reflected back.  For the Moon, it is on average about 12%.  Think about that the next night you are out and the full moon is shining above.  Only 12% of the light from the Sun reflects off the surface of the Moon.  Imagine what it would be like if it was 50% or higher!  Also, for another twist on this, consider that the average albedo of a paved, blacktop road surface is about 10%.  So, that bright orb in the night sky really isn’t any brighter than the road you may be driving or walking on!

Now let’s take a look at this new planet that was discovered by Kepler, TrES-2b, about 750 light-years distant in the constellation of Draco the Dragon.  Although this planet is extremely hot, about 1,800 degrees Fahrenheit (980 degrees Celsius, it is extremely dark, with an albedo of slightly less than 1%.  Coal has an albedo of about 1%, which is a something most people can relate to and it’s pretty dark, but we’ve found asteroids in our Solar System that have an albedo of about .6%.  On the other end of the spectrum we have Saturn’s icy moon Enceladus, which has an albedo of 99%.

Artist's impression of TrES-2b - Image courtesy of David A. Aguilar (CfA) Harvard Smithsonian Center for Astrophysics

So, it’s not beyond the realm of possibility that the asteroid that impacts Earth in the novel is so dark that the surveillance systems in place at the time could have missed it.  It’s nice to know that we are more active today as far as monitoring asteroids in the Solar System than we were ten years ago when the novel was started.

What is TrES-2b made of?  We don’t know.  Add that to the list of things we need to learn about in this vast Universe we live in.  The wonders never cease!

Till next time,

RC Davison

Celestial Jewelry

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The Hubble Space Telescope has taken a fascinating image of a planetary nebula known as the Necklace Nebula.

Necklace Nebula - Courtesy of the Hubble Space Telescope site

Planetary nebula are the remains of a star like our Sun as it goes through the final stages of its life expanding and blowing off its outer layers.  The bright blobs embedded in the nebula are areas of gas that are energized by ultraviolet light from the star at the center.  The blue-green color of the nebula reflects the hydrogen and oxygen present, with red indicating nitrogen.  The Necklace Nebula lies about 15,000 light years from us and is located in the constellation Sagitta.

It’s interesting to compare this planetary nebula with the remains of the supernova 1987a:

Supernova 1987a - Image courtesy of the Hubble Space Telescope

     Another piece of cosmic jewelry, but one made from a very different process and from a star that was much larger than our Sun. The supernova is the foundry that produces all the heavy metals we have today, from the iron in the hemoglobin of your red blood cells to the gold and silver in the jewelry you may be wearing right now.

     Both of these nebulae are still evolving, and as time passes they will continue to evolve into new shapes, and eventually (10s to 100s of thousands of years) they will fade from view.  But, their remains will fuel the next generation of stars and planets in the cosmos.

Till next time,

RC Davison

Farewell, Atlantis

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The end of the shuttle era came on Thursday, July 21 at 5:57:54 a.m. when Atlantis came to a full stop on the runway at the Kennedy Space Center.  The amazing image below is a fitting finish to an amazing program, regardless of any arguments about traveling to low Earth orbit versus going to the Moon or Mars.

Atlantis reentering the atmosphere taken from the International Space Station. Image courtesy of NASA

Here’s a link to a larger image.

Some statistics for Atlantis:  It has traveled 125,935,769 miles while it orbited the Earth 4848 times and spent a total of 307 days in space.  It’s good to have all the shuttles back safely on the ground.

On a Orbital Maneuvers related note: I’ve put up a video promo for the book on YouTube.

Till next time,

RC Davison

Of Sunspots and Solar Eruptions

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I was initially going to talk about some fascinating images of sunspots showing their structure in a way never seen before, but the Sun made an announcement on Tuesday that took solar astronomers by surprise and has moved to the top of the list.

On June 7th there was a huge eruption on the surface of the Sun, very different from anything observed before.

 

Coronal Mass Ejection, June 7, 2011 - NASA SDO

The above image shows this huge prominence. This gives you an idea of its size and how much of the Sun it covered, but check out the video below to see how dynamic this event was.

 

The video shows the eruption as seen by the Solar Dynamics Observatory at two different energies. The second, or greenish-blue image is looking at shorter wavelengths, or higher energy emissions. The other images with the disk in the center (an instrument called a coronagraph) are from the Solar and Heliospheric Observatory’s (SOHO) LASCO coronagraph and STEREO’s (Solar Terrestrial Relations Observatory). If you watch the video closely you will see material falling back to the surface of the Sun creating ejecta as they land.  For more information and more complete videos with descriptions go to The Sun Today.

 

Now on to something more sedate – sunspots.

 

The Sun is a very dynamic object, as evidenced by the images above, but from our place in the Solar System it seems pretty quiet and stable. The surface of the Sun is a frenzy of activity and this is no different when you approach the cooler sunspots that dot its surface.

 

Sunspot with Earth reference. Image courtesy of the Institute for Solar Physics

Work done by Göran B. Scharmer, Vasco M.J. Henriques, Dan Kiselman, (all from the Institute for Solar Physics of the Royal Swedish Academy of Sciences and the Department of Astronomy at Stockholm University), and Jaime de la Cruz Rodríguez (University of Oslo) has shown that the structure of the sunspot is a heaving mass of cells or filaments almost 1200 miles or about 2000 km long and about 90 miles (150 km) wide, which can be seen in the above image. The brighter, hotter filaments are areas of hot matter that is upwelling at speeds of 6,600 mph (10,800 kph), while the darker filaments are sinking at speeds of about 2,200 mph (3,600 kph).

 

The image below shows the speed of the sunspot’s filaments as measured by Doppler shift. The red filaments are moving away, or sinking while the blue ones are rising and moving toward the surface.

 

Sunspot filaments showing relative velocities. - Image courtesy of the Institute for Solar Physics

For more information and images visit the Institute for Solar Physics

 

These images should humble us, as they are indicative of how much we don’t know about the cosmos, let alone our nearest star.  There is so much to learn…

 

Till next time,

 

RC Davison

Rogue Planets

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Kepler has opened up the Universe for us with evidence that there are many more planets orbiting stars than we previously thought.  The consequences of this is that the potential for life beyond Earth has grown exponentially.  Recent news from a team of astronomers lead by Takahiro Sumi from Osaka University in Japan and published in the journal Naturehas revealed that there may be as many as 400 billion planets roaming the Milky Way Galaxy, free from their parent stars.

Rogue planet wandering through the galaxy - Image courtesy of NASA/JPL-Caltech/R. Hurt

This discovery was made by using a technique called gravitational lensing or microlensing in this particular case.  According to Einstein’s General Theory of Relativity, the gravitational field of a massive object will bend light that passes through it.  This technique has been used to view distant galaxies that are behind an intervening large cluster of galaxies, which magnify and distort the image of the more distant objects.

Gravitational Lensing - Distant galaxies are stretched into arcs by intervening clusters. Image courtesy of the Hubble Space Telescope

In the case of gravitational microlensing, the intervening objects are these rogue planets and the distant objects are stars.  The alignment of the star, planet and Earth is almost perfect, such that when the planet passes in front of the star its gravitational field causes the star to brighten and dim in a predictable fashion.  This is a brief event and will not repeat itself.

These objects are similar in mass to Jupiter.  And, if they are truly planets or possibly brown dwarf stars (small stars that generate heat but are too small to trigger the fusion process to burn brightly), they may have been ejected from their solar system of birth through the normal dynamics that force a solar system into a stable state.  Interestingly, this challenges the definition of planet, which was decided upon by the International Astronomical Union (IAU) and led to Pluto’s demotion to dwarf planet, but that is a a discussion for another blog.

The objects detected are fairly massive, which begs the question: What about smaller Earth-like planets?  Can we see them and how many of them are there out there?  As usually happens in the world of astronomy, discoveries bring more questions than they answer.

The discovery of these objects challenges the current theories of planetary evolution and possibilities for life in the Universe.  More research in this area will be conducted when NASA’s Wide-Field Infrared Survey Telescope (WFIRST) is launched, allowing for the faster blips of light to be detected, indicative of Earth-mass type objects.

Till next time,

RC Davison

Unique Views of the Cosmos

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Two items of interest popped up last week:

First:  The European Space Agency posted a very nice video showing the Andromeda Galaxy in light from X-rays to gamma rays.  About a third of the way into the video, one can see variable stars pulsing and other stars flashing as they go nova, thanks to the view from the XMM-Newton X-ray telescope. Check out “Andromeda’s coat of many colours“.  (Check out the post on 6, January 2011 under the galaxy category for more information about Andromeda.)

Andromeda Galaxy (M31) iImage courtesy of Tony Hallas and APOD.NASA.Gov

Second:  An image posted on the Astronomy Picture of the Day site by Juergen Michelbergershows in very unique detail how stars and planets are affected by Earth’s atmosphere.  Or, more appropriately, why stars twinkle and planets don’t.

The star Regulas (left) and Mars (right): Image by Juergen Michelberger

The star, being much further away from Earth than the planet Mars, presents an image that is much smaller in diameter than Mars.  This smaller point of light is affected by the variations of the Earth’s atmosphere due to temperature and moisture much more so than the larger source of light from the planet.  Consequently, the star’s image is randomly refracted, causing it to vary in color and brightness, while Mars shines on steadily over the ten second exposure.  The intricate image is due the camera being swung about.  Check out the link to APOD above for more information about this unique image.

Till next time,

RC Davison