Podcaster: Morgan Rehnberg
Title: Monthly News Roundup – Waves, Large and Small
Link : http://cosmicchatter.org
BICEP2: http://cosmicchatter.org/news/2014/3/17/jdykd88uqmnmjf1uljimpe5dc1xka8
Citizen science: http://cosmoquest.org/x/citizen-science/ ; http://www.galaxyzoo.org/
Titan waves: http://cosmicchatter.org/news/2014/3/20/waves-on-titan-maybe-but-dont-break-out-your-surfboard
Rings/Dwarf planet: http://solarsystem.nasa.gov/news/display.cfm?News_ID=46852 ; http://www.eso.org/public/news/eso1410/
Cosmos: http://cosmicchatter.org/news/2014/3/23/critiquing-cosmos-episode-3 ; http://cosmicchatter.org/news/2014/3/16/critiquing-cosmos-episode-2 ; http://cosmicchatter.org/news/2014/3/9/critiquing-cosmos-episode-1
Description: In this episode of the Monthly News Roundup, we find hints of waves at the dawn of time and on a nearby moon. Astronomers discover a new dwarf planet and an asteroid with rings. Watch Cosmos and then be do some astronomy yourself!
Bio: Morgan Rehnberg is a graduate student in astrophysics and planetary science at the University of Colorado – Boulder. When not studying the rings of Saturn, he develops software to help search for asteroids that might hit the Earth. He blogs and podcasts about astronomy and space science at http://cosmicchatter.org.
Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by — no one. We still need sponsors for many days in 2014, so please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at signup@365daysofastronomy.org.
Transcript:
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You’re listening to the 365 Days of Astronomy podcast for March 30th, 2014. I’m Morgan Rehnberg, here with Vivienne Baldassare, and this is the Monthly News Roundup. This episode was produced March 26th from Boulder, Colorado.
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The biggest news this month came from the BICEP2 collaboration, when they announced they had detected a signature in the cosmic microwave background that lends support to the theory of inflation.
The cosmic microwave background is the first light we can detect from the early universe. It permeates throughout space, and was first detected in 1964 by radio astronomers Penzias and Wilson as an unexplained source of noise on their radio antenna. After accounting for all possible sources of noise (including clearing bird droppings away from the antenna), there was still an excess – the cosmic microwave background. By studying tiny variations in the cosmic microwave background (or CMB), we can learn a lot about the size of the early universe, and the relative amounts of dark energy and matter.
The BICEP2 experiment was looking at the polarization of the CMB, or the way in which the light rays are oriented. There are certain polarization patterns which can only be created by specific scenarios. The B-mode polarization, which was detected by BICEP2, can be created by gravitational waves, or ripples in the fabric of space, produced in the early universe. The presence of this B-mode polarization supports the theory of inflation, which proposes that the universe went through a period of extremely rapid expansion very early on. The theory of inflation is important because, if proven, it would explain several observational oddities that have puzzled scientists for years.
Because the scope of this discovery is so incredibly large, its important to wait for confirmation of the results before we can say anything definitive about an inflationary period in the early universe. We also need to be sure that the B-mode polarization is actually due to gravitational waves from inflation. There are several experiments which should be able to back up the BICEP2 results; one is the POLARBEAR experiment in Chile, the other is the Planck space observatory.
If confirmed, this result has lots of other exciting implications. For one, it gives us another piece of evidence for the existence of gravitational waves, which have yet to be directly detected. It also gives us an example of gravity and quantum mechanics working together. The two theories have typically rule different realms (quantum mechanics dictating the motions of small particles, and gravity dominating larger objects), but they must have worked together in a fundamental way to produce the B-mode polarization.
Either way, this is an exciting step forward in our understanding of the early universe.
http://cosmicchatter.org/news/2014/3/17/jdykd88uqmnmjf1uljimpe5dc1xka8
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Ever wish you had become an astronomer? While it’s not all looking at pretty pictures and starring in television shows, astronomers get to do some pretty cool things and, thanks to the growing trend of citizen science, you can join in!
Astronomy and planetary science are really the only remaining scientific fields where amateurs can make a substantial impact, and demand for citizen involvement is increasing at a rapid pace. Spacecraft like the Lunar Reconnaissance Orbiter and telescopes like the Sloan Digital Sky Survey are generating enormous troves of data far faster than professional scientists can examine it. While computer algorithms can share some of the burden, there’s nothing as good for some tasks as the human eye.
In a paper released earlier this month, a group of scientists demonstrated that a lunar crater map generated by amateur scientists through CosmoQuest’s Moon Mappers program was just as accurate as maps generated by eight professional studies. Although individual participants showed more variability than their scientific counterparts, when many amateur mappers’ work was averaged together, the results were just as accurate and free of systematic biases.
In an era of budget cuts and stagnating funding, amateur efforts can produce scientifically viable results at a fraction of the cost and, in some cases, a fraction of the time! Interested in joining in the effort? Even a few minutes, just once, helps us move science forward. If mapping craters on the Moon isn’t your thing, CosmoQuest also offers the chance to map them on Mercury or Vesta instead. And, if you really just don’t like craters, the Galaxy Zoo offers you the chance to be the first to look at and classify galaxies from the Sloan Digital Sky Survey. Now that’s pretty neat!
http://cosmoquest.org/x/citizen-science/
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<Wave sounds>
The crash of waves against the shore is one of the most visceral reminders of the power weather has to reshape our world. The Earth has been transformed over and over
again by the wind, rain, and running water that buffets its surface. Of the terrestrial planets, only Mars experiences similar surface erosion, and, without surface water, wind is left as the only force reshaping the planet today,
That doesn’t mean that Earth is alone in experiencing a more complete climate. Saturn’s largest moon, Titan, is the remarkable host of an atmosphere thicker than the Earth’s and is the solar system’s only other home to liquid on the surface. We knew there was wind on Titan and we knew that there was rain, but not until results released this month from the Cassini spacecraft did we know that there were also waves. That’s right – in a world otherwise completely alien to ours, the waves are lapping at the seashore right now.
How were these waves discovered? It’s not as easy as you might think. Thick clouds in Titan’s dense atmosphere obscure the surface from view at visible wavelengths. This forces astronomers to use other parts of the electromagnetic spectrum, particularly the infrared and radar. In this case, Cassini’s Visible and Infrared Mapping Spectrometer took a series of images of a Titan lake over the course of 2012 and 2013. In all, four pixels in these images appeared anomalously bright.
The scientists carrying out these observations are careful to note that explanations other than waves could plausibly explain these bright pixels. Ideas that have been suggested include a floating iceberg and a shiny mudflat. But, it seems as if the case for waves is most compelling.
One last thing. I keep referring to these features as waves, but measurements indicate they are probably only a few centimeters high. So, if surfing is your thing, then the Earth is still the place to be!
http://cosmicchatter.org/news/2014/3/20/waves-on-titan-maybe-but-dont-break-out-your-surfboard
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We had two exciting discoveries within our solar system this month. The first was the identification of a possible member of the Oort Cloud. The Oort Cloud is a theoretical sphere of debris way out in the solar system, containing material leftover from when the planets were forming. Astronomers theorize that this is where some comets originate from. However, the Oort Cloud was yet to be observed.
Scientists have discovered a possible dwarf planet and Oort Cloud member in our extreme outer solar system. The object, called 2012 VP113, has an orbit whose closest point to the Sun is still 11 billion kilometers away, or 80 times the distance between the Earth and the Sun. This is far beyond the well-defined edge of the Kuiper Belt, which is comprised of small icy objects like Pluto. The only other object known to orbit that far away from the Sun is the dwarf planet Sedna. Both Sedna and 2012 VP113 were discovered near their points of closest approach to the Sun. At their farthest points (hundreds of times the Earth-Sun distance, they would be much too faint to discover), making observing members of the Oort Cloud very difficult for astronomers. The identification of even more members would go a long way toward helping us understand the source of comets in our present day solar system, as well as the formation of the solar system 4 billion years ago.
The next piece of solar system news is the discovery of the first asteroid known to have rings. Thus far, rings have only been found around gas giant planets like Saturn and Jupiter, so this marks the first rings found to exist around a smaller solar system object. The rings around this asteroid aren’t as spectacular as those around Saturn – there are just two and they’re very fine – but this is still incredibly exciting. Astronomers think that the rings could have formed when this asteroid had a collision with another, and small debris went into orbit around the asteroid. The presence of rings could provide a pathway for the formation of small moons around asteroids, and this discovery even has the potential to give insight into how our own moon formed.
http://solarsystem.nasa.gov/news/display.cfm?News_ID=46852
http://www.eso.org/public/news/eso1410/
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Finally, this month, the premiere of one of the most highly anticipated science programs of the last decade. Thirty-four years after Carl Sagan’s world-famous documentary Cosmos first hit the airwaves, astronomer and science advocate Neil deGrasse Tyson brings us another journey through the stars.
<Cosmos clip>
The first three episodes of the ten-part series have been a whirlwind of science. We’ve walked the days of the Cosmic Calendar, tracing the evolution of our universe from the Big Bang through to the formation of the Earth and the development of life.
We’ve explored how accidental variations in the genetic codes of all living things lead to mutations and how these mutations help or hinder organisms in their struggle for survival. The accumulated result of these variations and struggles and successes is evolution by natural selection and has shaped the living world around us.
We’ve traced the evolution of human thoughts on nature and the Universe, from the motions of the stars to the physics which governs the motions of the planets. And we’re not even a third of the way done!
This new generation of Cosmos is succeeding where its predecessor also succeeded: in bringing the wonders of the Universe, from the largest galaxy to the tiniest cell, to our attention with a clarity that’s impossible to ignore. And for viewers in more than 170 countries around the world, the wonder of the natural worlds and the laws which govern it are as critical a message as they are an entertaining one.
http://cosmicchatter.org/news/2014/3/23/critiquing-cosmos-episode-3
http://cosmicchatter.org/news/2014/3/23/critiquing-cosmos-episode-2
http://cosmicchatter.org/news/2014/3/23/critiquing-cosmos-episode-1
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Thanks for listening to this episode of the Monthly News Roundup. For more astronomy news and commentary, visit http://cosmicchatter.org or follow us at @cosmic_chatter on Twitter. As always, we welcome your comments and corrections at cosmicchatter@gmail.com. See you in April!
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End of podcast:
365 Days of Astronomy
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