New Horizons

[TheKnightWho]

1, despite Pluto's odd shape orbit it's barycentre lies within the Sun.
Jupiter's doesn't, and the Sun's wobble is caused by this.
2, yes it might not exist, but the principle remains. Comet like gas giants with trails have been detected already.
3, it's good to know that the asteroid that exploded over Russia a few years ago won't happen ever again now were a planet! As all asteriods have been cleared, umm they are over 10,000 Near Earth Objects catalogued already so I doubt that's the case.
Also Pluto and Charon have few if any craters unlike Mercury or Mars so maybe they are not many collisions out there as previsiously expected.

I feel there is far too much nostalgia for when there were 8 known planets. I think some people are scared to learn of too many planets that they won't know the names of.

Here's Mordor.

1) The barycentre of its orbit with its moons is the important part here - not its orbit with the sun. Every planet's barycentre with its satellites lies within itself - this is not the case for Pluto.

2) The reason the criterion exists is precisely *because* it is physically impossible. Things over a certain size achieve hydrostatic equilibrium - that's just the way things are. You might as well complain that the definition of water includes that it's wet.

3) You're missing the fact that these are not asteroids in *stable orbits*. Most are knocked out of the asteroid belt or the Kuiper belt by interactions within said belts, and if they do end up in stable orbits around the sun inevitably do so outside of the orbits of the planets. Occasionally this is because they crash into them, but almost always because they're thrown out of those orbits by that very planet.

 

[TheEdge]

Who cares about the definition now. Far more interesting is the fact that both Pluto and Charon appear to be geologically active which is pretty unexpected. Even more so when said geological activity cannot be attributed to tidal forces that cause the ones we see on some of the moons of gas giants. Ergo Pluto and Charon must have some sort of internal heat source. That and the whale has been renamed Cthulhu Regio.

And, a on a lighter (but sadder) note...

 

[ainsworth74]

And, a on a lighter (but sadder) note...

That's almost as sad as the Spirit comic:

 

[NorthernSpirit]

The choice of which minor planet New Horizons will visit in the Kuiper-Edgeworth Belt will be made in August.

I'm glad the mission went well.
Not only does Pluto have a giant heart and a whale as surface features it has pale near white, orange, and black colour in different regions.
It's hardly just a frozen grey rock some expected.

Pluto and Charon are tidally locked meaning that one hemisphere on each part of the "double planet" faces the other always. Still waiting for the pictures of Pluto's moons, Nix, Styx, Kerberos and Hydra though.
Charon is black and grey and looks totally different to Pluto, which is interesting.

When will the next mission to explore these strange new worlds start?
Eris, Makemake, Quoar, Sedna, Haumea are all large with virtually no information available on them. I hope NASA decides to fund a second mission soon.

Depending on where about Makemake, Quoar and Haumea are in the Solar System and if they're in the flight path of New Horizons, then it could be possible to see those 'Kuiper Planets' too. I didn't mention Eris or Sedna as these two aren't anywhere near the probe's flightpath going by what I've read.

 

[me123]

None of those planets are potentially reachable by New Horizons. They have used Hubble to find some candidate bodies in the Kuiper Belt and they'll be trying to visit at least one of those smaller objects. It will be really interesting to see one of these small objects - again, we have not seen anything like these before so the pictures should be really interesting.