SPAAAAAAACE 5/13/13 - Chris Hadfield Comes Home
Chris Hadfield is one of the coolest guys ever:
http://www.guardian.co.uk/science/2013/ ... ce-station
The first Space Rock Star. He has done a lot to really humanize astronauts, I think. They are friggin awesome, but still real people. And they like to do real things. For me, this really showed emotion. The guy just loves space!
Welcome home, Commander Hadfield!
http://www.cbc.ca/news/technology/story ... earth.html
Check it live! Godspeed!
Watch some of the biggest solar flares of the year:
http://www.space.com/21118-biggest-sola ... tions.html
Here is more about solar flares, like what causes them, and what they can cause.
http://www.space.com/21121-solar-flares ... ation.html
Here, Gany tells us about these dastardly...or lonely? Rogue Planets!
Alright everybody, it's time to go rogue!
Rogue planets are planets which don't orbit any star. They just fly through space alone, without "the man" keeping them down.
There are thought to be two ways for a planet to have gone rogue. The first is that the planet originally formed as part of a solar system, orbiting a star, but then due to gravitational interactions in the early, more turbulent solar system, the planet was flung out into interstellar space, left to wander its path alone, like some poor lonely black-sheep of the solar system family. This could happen in the early stages of a solar system, when the orbits of planetary bodies are chaotic and irregular, before they settle down to a more ordered state. The other, less depressingly scary way, is that the planet was formed in a cluster, in much the same way as a star but never obtained enough mass to ignite fusion. This type of object is known as a brown-dwarf, an almost-but-not-quite star. Brown-dwarfs are like giant Jupiters, mainly composed of hydrogen, but not massive enough to ignite fusion in its core, and therefore they don't shine.
Rogue planets can be either Jovian (gas giants) or terrestrial (rocky, like Earth). Generally, these planets have a similar orbit to the stars, orbiting the centre of the galaxy, although their orbits tend to be highly eccentric, especially the ones turned rogue by ejection. The rogue planets would be dark, and very cold, without a host star to provide heat energy. It is possible, however, that some terrestrial rogue planets may maintain a type of atmosphere. A rogue planet doesn't necessarily have to remain lonely forever, though. If it happens to enter a solar system, the orphan planet might get adopted by the star. It may get caught by the gravitational effects of the objects in the system and assume a more regular orbit about the star. Rogue planets had been predicted for decades, but the first direct observations were made in 2011, and since then at least ten have been identified and confirmed. It is thought, due to recent observations, that there are probably more rogue planets than stars in our galaxy.
So the question is, "could Earth ever go rogue?". And the answer is "yes, it totally could, but not for a few 10's of millions of years, so don't worry!". The orbits of the bodies in our solar system are well understood, but only for the short term. (Note: "the short term" for an astronomer is like 10 million years). After a certain point, the rather tenuous order in our system becomes uncertain and unpredictable. Small and gradual gravitational influences build up over time and it becomes impossible to predict the orbits accurately after about 10 million years or so. For example, take Jupiter and Mercury. The perihelion of both planets (perihelion is when the planet is closest to the Sun), precesses at a rate of about 1.5 degrees every 1000 years. If the perihelion of both planets synced up eventually, and both planets were at their closest to the Sun at the same time, the gravitational effect from Jupiter on Mercury could accumulate and eventually just pull Mercury off course altogether. This of course would have an effect on Venus and Earth etc. and while that would not be enough to eject Earth (probably), it is a good example of how easily the balance of orbits could be disturbed. Considering the amount of objects on our solar system and the gravitational influence that they all have on each other, and including the possibility of the influence of outside objects such as asteroids, the possibility of Earth going rogue is unlikely in the short term, and possible in the long term.
But, like I said, don't worry! We have 10 million years of safety (well, safety against expulsion from the solar system at least, in space you are never truly safe), and by the time anything does happen we should be able to thwart our demise by escaping in our super-advanced warp-enabled FTL-travelling starships, right? Right! Better get on that shit astro-engineers!
If you want to read more about rogue planets:
http://www.universetoday.com/94656/rogu ... her-stars/
Share on facebook and twitter, or Gany will use psychic power to destroy a life-bearing planet.
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