Newfound planet orbits backward

In summary, a newfound planet named WASP-17 has been discovered to orbit its host star in a retrograde or backwards direction, which is uncommon compared to the normal orbital direction of planets. This is believed to be the result of a near-collision between the planet and another object. The star and its planet are located about 1,000 light-years away and were found by the UK's Wide Area Search for Planets project. Further discussions include the possibility of other planets with retrograde orbits and the effects of tidal locking on Venus' rotation and orbit.
  • #1
Evo
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I was speaking with a friend about this today, I don't see a thread on it.

Newfound planet orbits backward

Planets orbit stars in the same direction that the stars rotate. They all do. Except one.

A newfound planet orbits the wrong way, backward compared to the rotation of its host star. Its discoverers think a near-collision may have created the retrograde orbit, as it is called.

The star and its planet, WASP-17, are about 1,000 light-years away. The setup was found by the UK's Wide Area Search for Planets (WASP) project in collaboration with Geneva Observatory.

http://www.msnbc.msn.com/id/32391095/ns/technology_and_science-space/
 
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  • #2
I was just about to post this...

Very interesting.
 
  • #3
That's nothing. Kapteyn's Star orbits the galaxy retrograde.
 
  • #4
What happens when they flush their toilets?
 
  • #5
Huckleberry said:
What happens when they flush their toilets?

They invert :O.
 
  • #6
Huckleberry said:
What happens when they flush their toilets?

They get wet!
 
  • #7
How does one measure the axis of rotation of a distant star?
 
  • #8
Planets orbit stars in the same direction that the stars rotate. They all do. Except one.

A newfound planet orbits the wrong way, backward compared to the rotation of its host star. Its discoverers think a near-collision may have created the retrograde orbit, as it is called.

i wonder if they made a small mistake. i think venus orbits backwards also
 
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  • #9
flatmaster said:
How does one measure the axis of rotation of a distant star?

red/blue shift maybe?
 
  • #10
fourier jr said:
i wonder if they made a small mistake. i think venus orbits backwards also
No, Venus rotates backwards. It orbits forwards, like the rest of us.
 
  • #11
What is the chance that a planet-sized object may be captured exclusively by a star's gravitation, to orbit against the rotation of a the star? Perhaps smaller planetoids (like Pluto), difficult to see outside out own solar system, would be much more likely to be captured in the first place.

Can a planet in a binary system have a oscillating trajectory? My guess is that it would be more likely ripped apart or fall into a star.
 
  • #12
I deleted a 2012 doom post by a regular member and the responses. Please check your references before posting obvious stupid stuff. Snopes.com is a good place to start for obvious stuff. Thanks.
 
  • #13
DaveC426913 said:
No, Venus rotates backwards. It orbits forwards, like the rest of us.

thx for clearing that up. does that have anything to do with why a day on venus is longer than a year?
 
  • #14
fourier jr said:
thx for clearing that up. does that have anything to do with why a day on venus is longer than a year?

Yes.

It orbits the sun (definition of a year) every 224 days, but it rotates on its own axis (definition of a day) every 243 days. The fact that the axial rotation is slower than the orbit is tantamount to a retrograde rotation.
 
  • #15
DaveC426913 said:
Yes.

It orbits the sun (definition of a year) every 224 days, but it rotates on its own axis (definition of a day) every 243 days. The fact that the axial rotation is slower than the orbit is tantamount to a retrograde rotation.

Venus has an actual physical retrograde sidereal rotation. As a result, its solar day is 116.5 days long.
 
  • #16
DaveC426913 said:
Yes.

It orbits the sun (definition of a year) every 224 days, but it rotates on its own axis (definition of a day) every 243 days. The fact that the axial rotation is slower than the orbit is tantamount to a retrograde rotation.

Janus said:
Venus has an actual physical retrograde sidereal rotation. As a result, its solar day is 116.5 days long.

Interesting. I wonder how long before it is tidally locked to the sun. Anybody know if there is an estimate of this?
 
  • #17
I read about this too on Wednesday, It was listed on http://news.bbc.co.uk/2/hi/science/nature/8197683.stm" [Broken]. So the planet's name WASP-17 has to do with the 'Wide Area Search for Planets' consortium of UK universities
Very interesting that we are able to deduce this kind of information for planets orbiting other stars.
 
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  • #18
Redbelly98 said:
Interesting. I wonder how long before it is tidally locked to the sun. Anybody know if there is an estimate of this?

Hard to tell.
We don't know yet if there is a cause for a particular resonance between the Earth and Venus or whether it is just a coincidence. Venus' rotation and orbit are such that whenever Earth and Venus are in inferior conjunction (when they are at their closest to each other) Venus always presents the same side to the Earth.

There is a formula to calculate tidal locking times. it is

[tex]t= \frac{\omega a^6 I Q}{3GM^2 K_2 R^5}[/tex]

[itex]\omega[/itex] is the initial spin rate (radians/sec)
a is the semi-major axis of the orbit
I is the moment of inertia of the planet
Q is the dissipation factor
G is the gravitational constant
M is the mass of the sun
[itex]K_2[/itex] is the Love number
R is the radius of the planet.

However, Q and K2 are not well known except for the case of the Earth and moon.
 
  • #19
Janus said:
There is a formula to calculate tidal locking times. it is

[tex]t= \frac{\omega a^6 I Q}{3GM^2 K_2 R^5}[/tex]

[itex]\omega[/itex] is the initial spin rate (radians/sec)
a is the semi-major axis of the orbit
I is the moment of inertia of the planet
Q is the dissipation factor
G is the gravitational constant
M is the mass of the sun
[itex]K_2[/itex] is the Love number
R is the radius of the planet.
Love number?
 
  • #20
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1. What does it mean for a newfound planet to orbit backward?

A newfound planet orbiting backward means that it orbits around its star in the opposite direction of most other planets in our solar system. This is also known as a retrograde orbit.

2. How is the direction of a planet's orbit determined?

The direction of a planet's orbit is determined by the initial conditions of the solar system during its formation. The direction of rotation of the protoplanetary disk and the direction of the star's spin play a role in determining the direction of a planet's orbit.

3. Are there any other planets in our solar system that orbit backward?

No, all eight planets in our solar system orbit in the same direction, with the exception of some moons that have retrograde orbits. However, there are other known exoplanets (planets outside of our solar system) that have retrograde orbits.

4. What are the potential causes of a planet having a retrograde orbit?

There are several potential causes of a planet having a retrograde orbit. It could be due to interactions with other planets or objects in the solar system, a close encounter with another star, or a collision with another object that caused the planet to change its orbit.

5. How does a planet's retrograde orbit affect its characteristics and behavior?

A planet's retrograde orbit can affect its characteristics and behavior in several ways. It can lead to extreme temperatures and weather patterns, as well as changes in the planet's magnetic field. It may also affect the planet's ability to host life, as it can alter the amount of radiation and light it receives from its star.

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