New Horizons successfully flew by Jupiter today, adding 9000 miles per hour to its speed and aiming it for its next rendezvous: Pluto.
I haven’t seen too many images yet (just one cool one of my boy, the Spot, over at the New Horizons site). There will be plenty to look at in the coming day or two, I’m sure!
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Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He has written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic, and fights misuses of science as well as praising the wonder of real science.
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February 28th, 2007 at 1:09 pm
I’ll be so happy to finally have a close look at Pluto. It’s like when I was a kid, there were various dogmas that most people had spent their whole lives with, such as “atoms are too small to see”. In my lifetime it became practical to image chemical atoms. Pluto is another of those kinds of things. I’ve spent decades knowing little more of it than that it exists. Now, very soon, that’ll all be a thing of the past.
February 28th, 2007 at 1:49 pm
Atoms WERE to small to see,,,with visible light, which was all we had available in those days.
New technology, new minds to think about the problem. That’s why we cherish the young.
Arthur Clark once said,” When a well known, respected scientist says something is possible, he’s almost certainly right. When that same scientist says something is IMPOSSIBLE, he’s almost certainly wrong.”
A one time head of the patent bureau wanted to close the patent office because,”Everything worth discovering, had been.”
Six months before the Wright brothers flew at Kitty Hawk, a renowned scientist claimed,”Heavier that air flight would not come for a 1000 years, if ever,,,”
I don’t recall their names, because they were wrong.
The lesson here is a truism. Anything not forbidden(by natural law) is inevitable and if you wait long enough, nothing is forbidden,,,
I love the concept of the Multiverse. Perhaps that theory is inclusive enough that nothing will be forbidden,,,
GAry 7
February 28th, 2007 at 2:11 pm
Is “fly blew” a new color?
February 28th, 2007 at 2:31 pm
Gary Ansorge said,
“A one time head of the patent bureau wanted to close the patent office because, ‘Everything worth discovering, had been.’”
That is an urban legend. It never actually happened.
February 28th, 2007 at 4:17 pm
It says that NH passed within 1.4 million miles of Jupiter. I thought it would get closer.
Still, from Jupiter to Pluto in 8 years isn’t half bad. Comparable to Voyager 2 going from Jupiter to Neptune in 10.
February 28th, 2007 at 6:23 pm
Phil (or anyone who knows I guess), I have an incredibly dumb question.
Do probes like New Horizons actually orbit the sun in an expanding spiral, or do they shoot out away from Earth in a straight line?
Thanks!
February 28th, 2007 at 6:41 pm
Mark Martin Says: “Now, very soon, that’ll all be a thing of the past.”
You should define “soon.” Maybe in astronomical terms, but we still have to wait another eight years!
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Gary Ansorge Says: “Six months before the Wright brothers flew at Kitty Hawk, a renowned scientist claimed,’Heavier that air flight would not come for a 1000 years, if ever,,,’”
Even better, in the summer of 1902, just over a year before their first successful powered flight, the brothers had a particularly bad few sessions with the glider. Wilbur wrote in his journal that he was now convinced that controlled, powered human flight was at least 50 years away!
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TheBlackCat Says: “That is an urban legend. It never actually happened.”
The part about it being the head of the Patent office saying it is a UL, but I thought there was a motion proposed in Congress to abolish the PO (uh, that’s the “Patent Office”, not “Post Office
- Jack
February 28th, 2007 at 6:48 pm
CoffeeJedi Says: “Do probes like New Horizons actually orbit the sun in an expanding spiral, or do they shoot out away from Earth in a straight line?”
Everything in the space around the sun (or any other massive body) is constrained by physics to travel in an elliptical orbit. In the case of New Horizon and other probes, they modify this at the beginning by kinking their path around planets, usually to speed them up and cut down on travel time. Once they’ve performed their mission, though, they settle into a regular elliptical orbit. I’m not familiar with NH’s trajectory, but I would presume it’s going to wind up in a fairly extreme ellipse, like a comet, which makes it more like the “straight line” you mentioned.
So far, only four probes (two Pioneers and two Voyagers) have picked up enough speed from their planetary fly-bys to actually leave the solar system.
- Jack
February 28th, 2007 at 6:54 pm
I’ve always wondered how spacecraft can gain speed in these slingshot maneuvers. It seems at first glance that any speed that the craft gained as it approached the planet would be lost on its departure. You know, conservation of energy and all that. There must be some part of the physics that I am missing. Can anyone explain?
February 28th, 2007 at 8:02 pm
I don’t know if this helps, but it’s a really fun applet to distract you while you think about it.
http://galileoandeinstein.physics.virginia.edu/more_stuff/flashlets/Slingshot.htm
February 28th, 2007 at 8:19 pm
New Horizons spacecraft is already past Jupiter? Wow, that was quick. I remember December 3, 1973 when Pioneer 10 made it’s closest approach to Jupiter gaining speed and investigating that most large planet during it’s float by. Then, in June 1983, Pioneer 10 went beyond Neptune’s orbit (which at that time was further than Pluto’s orbit).
Even though space probes travel faster in the 21st Century, those probes launched in the 20th Century still rock.
February 28th, 2007 at 9:02 pm
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I’ve always wondered how spacecraft can gain speed in these slingshot maneuvers. It seems at first glance that any speed that the craft gained as it approached the planet would be lost on its departure. You know, conservation of energy and all that. There must be some part of the physics that I am missing. Can anyone explain?
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From the point of view of Jupiter, it is symmetrical. The probe gains some speed on the way in and loses the same amount on the way out. BUT, Jupiter is moving. The probe passes “behind” the planet and steals some of its angular momentum. So, from the point of view of the Sun, it gains about 15,000 kph.
February 28th, 2007 at 9:10 pm
***I’ve always wondered how spacecraft can gain speed in these slingshot maneuvers. It seems at first glance that any speed that the craft gained as it approached the planet would be lost on its departure.***
From Jupiters point of view this is correct. The spacecraft falls towards the planet gaining speed, and then flies off losing the same amount of speed.
However, because Jupiter is also orbiting the sun, it is essentially ‘dragged’ along behind Jupiter. Jupiters ‘year’ grows a little bit longer and the space craft speeds up (think of riding a bicycle and getting caught in the slip stream of a passing truck).
It also can work in reverse if you want to slow down. You approach the planet head on instead of sneaking up behind and you will lose velocity.
March 1st, 2007 at 4:56 am
Jack Hagerty: “Everything in the space around the sun (or any other massive body) is constrained by physics to travel in an elliptical orbit.”
Not so. That’s only if the velocity of the object in question is less than the escape velocity of the Sun at its distance from the Sun.
New Horizons is currently traveling in a *hyperbolic* orbit, since it is traveling at faster than solar escape velocity away from the Sun. This orbit is still shaped by the Sun — gravity doesn’t just “go away” if you travel fast enough — but the orbit is not an ellipse; left to itself, New Horizons will never come back.
That said, the degree to which New Horizons’ trajectory is deflected from a straight line by the Sun is relatively small.
Lyc: “It also can work in reverse if you want to slow down. You approach the planet head on instead of sneaking up behind and you will lose velocity.”
In fact, MESSENGER is using maneuvers much like this to lose momentum and fall in towards the Sun on its way to Mercury.
March 1st, 2007 at 5:11 am
[…] Passin’ By A peek above our garters to Dr. BA of BadAstronomy for reminding us about […]
March 1st, 2007 at 5:34 am
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A one time head of the patent bureau wanted to close the patent office
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Little did he know that, a century later, you’d be able to patent just about anything that popped into your head.
(Unfortunately, this story appears to be an urban legend. http://ask.yahoo.com/20050407.html )
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think of riding a bicycle and getting caught in the slip stream of a passing truck
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Uh, I’d rather not, thanks. ::shudder::
March 1st, 2007 at 5:36 am
It seems rather obvious now. Thanks!
March 1st, 2007 at 10:42 am
MattFunke Says:
> >Jack Hagerty: “Everything in the space around the sun (or any other
> > massive body) is constrained by physics to travel in an elliptical orbit.
> Not so. That’s only if the velocity of the object in question is less than the
> escape velocity of the Sun at its distance from the Sun.”
Yes, it was my unspoken assumption that NH was travelling at less than solar escape velocity.
> New Horizons is currently traveling in a *hyperbolic* orbit, since
> it is traveling at faster than solar escape velocity away from the Sun.
Making it interstellar probe #5?
- Jack
March 1st, 2007 at 10:45 am
Lyc Says: “However, because Jupiter is also orbiting the sun, it is essentially ‘dragged’ along behind Jupiter. Jupiters ‘year’ grows a little bit longer ”
Doesn’t Jupiter’s “year” get a little shorter? By removing some of it’s orbital energy it falls into a slightly lower orbit, which has a shorter period.
- Jack
March 1st, 2007 at 11:54 am
The easiest visualization (though not completely correct) of a slingshot is to think of throwing a ball against a railroad car that’s standing still. That would be the same as throwing it against a wall.
Now, get the car rolling towards you and throw the ball at it. The ball will pick up momentum from the car and the car will slow down a bit.
Be sure to get out of the way of the car.
(The author is not liable for those attempting this experiment and forgetting to get out of the way of the car)
March 1st, 2007 at 1:19 pm
Jack, you’re correct about that. Jupiter has lost a tiny amount of its orbital energy, and has now entered into an orbit of slightly longer period and altered eccentricity.
March 1st, 2007 at 1:55 pm
…excuse me: *shorter* period.