Podcaster: Morgan Rehnberg
Title: Monthly News Roundup – Fifty Score and Counting
Link : http://cosmicchatter.org
Description: In this episode of the Monthly News Roundup, a new milestone is reached in the search for exoplanets. Strange galaxies and planets are found and we resolve a case of mistaken identity. LADEE tests next generation technology, while Juno overcomes a problem.
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.
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You’re listening to the 365 Days of Astronomy podcast for October 27th, 2013. I’m Morgan Rehnberg, here with Vivienne Baldassare, and this is the Monthly News Roundup. This episode was produced by Cosmic Chatter in Boulder, Colorado.
We start this month with the discovery of the one thousandth planet outside of our solar system. The pace of discovery has been remarkable – it was only eighteen years ago that the first-ever exoplanet was discovered.
You might be surprised to find out that this is only the thousandth planet detected. After all, the Kepler telescope has reported more than three thousand planetary candidates. The trick is in confirmation. Kepler searches for planets by looking for the dimming of a star’s light as the planet passes in front. The problem is, other phenomena, like star spots, can also cause the light to dim. In order to be certain they’ve found a planet, astronomers require that a second detection method is used to confirm its existence. This greatly slows down the process. Of those one thousand confirmed planets, only about a hundred were actually found by Kepler. That means that our catalog of planets is likely to grow substantially in the coming years.
The ones we’ve found already, however, have upended most theories about the formation and evolution of planets. We’ve found planets in places previously deemed impossible, forcing the development of brand-new ideas about how star systems are born. If it takes only hundreds of planets to do this, imagine what the future holds. If indeed most stars in the galaxy host planets, we’ve still got a whole bunch to learn!
One mystery that has arisen from the host of new planets discovered over the last few years is that of “hot Jupiters”. These are Jupiter-like planets that orbit extremely close to their stars. These gas planets could not have formed in such a hot environment, meaning they must have formed somewhere else and traveled inward. One theory is that interactions with other planets or stars disrupt these Jupiter-like planets and cause them to migrate towards their host stars.
Astronomers recently discovered a system consisting of a star and two planets in which the plane of the planets’ orbit is tilted compared to the plane of the star’s rotation. A third, more distant companion object is suspected to have disrupted the orbit of the inner planets, tilting their orbits to match its own orbital plane. This is the first time such a tilting scenario has been observed.
Although the planets in this system are not hot Jupiters, this research is helpful for understanding how planetary systems evolve and finding out which processes can change the orbits of planets.
Ever gotten stuck waiting for an online video to buffer or a software update to download? You’re not alone. We all pine for faster, more reliable internet access and NASA is no exception. Unlike you and I, however, the space agency is doing something about it. Last month saw the launch of the Lunar Laser Communication Demonstration aboard the LADEE spacecraft.
LADEE will spend the next few months studying the atmosphere of the Moon, but she’s also testing this next generation communication platform. Only days into the test, NASA has already demonstrated faster-than-ever communication speed. The maximum download rate of 622 megabits per second is nearly one hundred times faster than the average internet speed in the United States.
How does this technology work? It’s actually not that different than how the internet is transmitted here on the Earth. Pulses of light act as bits, or fundamental pieces of data. A special laser sends millions or billions of pulses every second, allowing for even complex data to be represented. You can think of it kind of like a modern-day Morse Code. On Earth, these light pulses are guided by fiber optic cables, but that’s not possible in space. Instead, special algorithms correct the incoming data for any errors during transmission.
This technology will start to roll out on spacecraft in the coming decade or so. It will mean more and higher-quality data can be returned from all over the solar system. Just as important, these lasers require much less power than big radio dishes, meaning that scientists have even more juice to devote to their experiments.
A discovery made possible by the chance alignment of two galaxies has created an astronomical mystery. Astronomers studying distant galaxies with the Hubble Space Telescope came across an oddball in their sample; one galaxy appeared to be extremely young. The light coming from it is very blue, indicating that it contains lots of young, hot stars. This object turned out to be a lensed galaxy. Lensing occurs when light from an object is bent by the gravity of an object in front of it. Lensing acts like a natural telescope, magnifying the image of the background object. Astronomers found that the light from this distant star-forming galaxy is being magnified by a galaxy sitting between it and us. Since the galaxy’s image is blown up, astronomers can see more detail than they typically would be able to.
The unusual galaxy is a dwarf starburst galaxy; a tiny, young galaxy that is forming stars very quickly. Systems in which a young, star-forming galaxy is lensed by an older galaxy in front of it were previously thought to be extremely rare, but this is the second one discovered by astronomers. This may mean that dwarf starburst galaxies are more common than astronomers thought, forcing us to rethink our models of how galaxies form and evolve.
A recent discovery of a nearby free-floating brown dwarf was widely reported as the discovery of a free-floating Jupiter-esque planet. Brown dwarfs can be thought of as failed stars; they are thought to form like stars do, but don’t have enough mass to achieve the temperatures and pressures necessary to fuse hydrogen into helium, like normal stars do. Instead of burning brightly, brown dwarfs shine dimly and slowly fade as they cool down. Brown dwarfs can sometimes have properties that are similar to properties of large gas giant planets.
Even though this newly found object is not a planet, this is still a significant discovery. This lonely brown dwarf is only about 12 million years old, a baby by astronomical standards. It weighs in at just 6 times the mass of Jupiter. Brown dwarfs had previously been thought to always be more massive than 13 times the mass of Jupiter, but observations of objects like this show us that they can be much smaller. And just because it isn’t a planet doesn’t mean it can’t help us learn about them. This is the first free-floating object that is similar in mass, color, and age to young, dusty gas giant planets we observe around nearby stars. This object can serve as an analog to young gas giant planets, and studying it may help us learn more about both brown dwarfs and planets.
We end this month with an eventful visit from the Juno spacecraft. Launched two years ago, Juno swung by the Earth for a gravity assist in October before continuing its flight to Jupiter. Shortly after passing the Earth, however, the spacecraft temporarily put itself into safe mode.
Going into safe mode is a spacecraft’s response to unfamiliar or unexpected conditions. In such a circumstance, the onboard computer turns off unessential equipment, points the solar panels at the Sun, and directs the antenna towards the Earth. There it waits until engineers can diagnose the problem. Sometimes, there really isn’t an issue and the ship can return to normal operations. Other times, a software update is needed to straighten things out. In this case, Juno was quickly restored to full operation.
The craft was in the vicinity of the Earth in the first place because it needed a gravity assist to reach Jupiter. Instead of using heavy and expensive fuel, many spacecraft use other planets to slingshot them in the direction they need to go. This steals a tiny amount of energy from the planet and gives it to the ship in the form of a faster speed. Juno still has a ways to go, however. It won’t actually arrive at Jupiter until 2016.
Once it does get there, a one year mission to study the planet will commence. Key goals for researchers include characterizing Jupiter’s composition and understanding its magnetic fields. In the meantime, it looks to be smooth sailing on the interplanetary seas.
Thanks for listening to this episode of the Monthly News Roundup. For more astronomy news and commentary, visit www.cosmicchatter.org or follow @cosmic_chatter on Twitter. As always, you can contact us with your comments and corrections at email@example.com. See you in November!
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