New Horizons flyby of Pluto

The Chronicler · **on:** July 07, 2015, 10:30:17 PM

The New Horizons space probe, which launched back in January 2006, is about to make a close flyby of the dwarf planet Pluto. Until now, this tiny and very distant world remained largely unknown (even the Hubble Space Telescope couldn't reveal more than a fuzzy image). Even though closest approach won't be until next week (July 14), the space probe is already close enough to reveal features that have never been seen before, such as that it's color is a reddish brown (very much like Mars) with large dark spots along the equator, and its large moon Charon (which, unlike Pluto, is grey) has what appears to be a polar cap that's darker than the rest of the surface.

Pluto has remained one of the last unexplored worlds in our Solar System, but that will soon change. Who else is fascinated by what New Horizons is going to reveal about this distant dwarf planet?

Kor · **Reply #1 on:** July 08, 2015, 12:57:19 AM

I'll be interested in what it uncovers.

vonboy · **Reply #2 on:** July 08, 2015, 09:01:15 AM

Been looking forward to this since I found out about it sometime last year. It's crazy to think when New Horizons was first launched, Pluto was still considered a planet. Seems like so long ago it lost it's status as a planet.

A little plugging here, but I've been watching SciShow Space for updates on space based missions and findings, and what not. They should be putting up whatever is discovered next week pretty soon after it happens.

Ptyra · **Reply #3 on:** July 08, 2015, 11:37:35 PM

Go, Bill Cipher space probe, go!

...no seriously.

It looks terrifyingly like Bill Cipher from Gravity Falls, right down to the top hat and gold triangle.

rhombus · **Reply #4 on:** July 09, 2015, 10:19:18 AM

I am excited to see what discoveries this probe uncovers.

When its computer had a glitch and it went into 'safe mode' a few days ago I fear for the worst, as a flyby mission doesn't really allow for a re-do if communications are restored too late. However, it now seems to be operating normally, and it actually released a stunning color view of Pluto today. So that's a good sign.

Although it may take us a while to get all of the data back from the probe. At about 1 kb/sec bandwidth (due to the great distance) NASA estimates that it will take about a year to get back just the 14 days of information from the flyby. :blink:

Chiletrek · **Reply #5 on:** July 09, 2015, 01:46:15 PM

Hello:
I never really imagined I would have get to see Pluto's first colour pic here in GoF

. It will be amazing when this probe finally gets to do it's flyby path in the next few days.

Also, to see what is that dark huge area been there since the first pic Hubble took years ago.

Kor · **Reply #6 on:** July 10, 2015, 11:27:04 AM

Interesting, so that is what color Pluto was. I was always curious what it's real color was.

The Chronicler · **Reply #7 on:** July 12, 2015, 10:05:35 PM

I'm not sure which site to go to for images to post, but I've read that the latest image released today shows the side that always faces Charon, and is also the side with those mysterious large dark spots. This is the side that will be facing away from New Horizons at the time of it's flyby in a few days, so it's very likely that today's image will be the highest resolution image we will have of that portion of Pluto for a very long time.

Kor · **Reply #8 on:** July 13, 2015, 11:45:27 AM

Cool, I'm looking forward to that. Amazing to think that soon we'll be able to see high res images of a planetary body in the solar system, but very very far away. Neat.

Nick22 · **Reply #9 on:** July 13, 2015, 12:56:38 PM

Pluto takes almost 250 years to go around the sun,. and its orbit is so erratic it sometimes is closer to the sun than Neptune is.

Kor · **Reply #10 on:** July 13, 2015, 04:23:32 PM

I think I read somewhere long ago that there was a theory that Pluto was maybe a oort cloud, I think it's called, object that got close enough to the sun to be caught in an orbit, or maybe it was once one of Neptune's moons that was knocked out of orbit.

The Chronicler · **Reply #11 on:** July 13, 2015, 09:12:32 PM

Tomorrow is the big day! The moment of the closest approach with be at 11:49 UTC (7:49 am EDT), although we won't receive confirmation of the flyby until many hours later, at least late in the evening, so have patience.

Coincidentally, tomorrow also marks the 50th anniversary of the Mariner 4 flyby of Mars, which provided the very first close up images of another planet for the first time. Pretty interesting to think that the era of initial exploration of our Solar System will have lasted for exactly 50 years.

Nick22 · **Reply #12 on:** July 14, 2015, 12:27:32 AM

well we now know that Pluto is bigger than previously thought. its the biggest in size of the beyond Neptune objects,. perhaps the new info about its size will result in it regaining its former planet status?

rhombus · **Reply #13 on:** July 14, 2015, 02:14:13 AM

^ I highly doubt as it has not "cleared its orbit" as is required in order to be designated a planet. Pluto makes up less than 10% of the mass within its orbit, whereas Earth (by comparison) makes up over 98% of the mass within its orbit.

Nick22 · **Reply #14 on:** July 14, 2015, 09:39:13 AM

if you require it to 'clear its orbit, than none but the biggest planets qualify, as even Earth hasnt completely cleared its orbit.

Kor · **Reply #15 on:** July 14, 2015, 10:53:56 AM

This may spark debate among some of Pluto gaining it's planetary status again.

Personally I'll enjoy the much closer views of Pluto's surface and Pluto itself.

rhombus · **Reply #16 on:** July 14, 2015, 04:47:53 PM

Quote from: Nick22,Jul 14 2015 on 08:39 AM

if you require it to 'clear its orbit, than none but the biggest planets qualify, as even Earth hasnt completely cleared its orbit.

Indeed. Though if we did not require such objects to clear its orbit (more information on that requirement can be found here) then we would have dozens of objects of rather small size being called 'planets' which would diminish the meaning of the word from what it has generally indicated in recent history, which is to indicate that an object is among the most prominent in the solar system that dominates its orbit. From the chart on that page you can see that Earth, Venus, Jupiter, and the other planets all have planetary discriminate values of 2400 or more (Earth's is 1700000), whereas Pluto only has a value of 0.077. Based upon that both Ceres (0.33) and Eris (0.10) would have more of a claim on planethood than Pluto.

Nonetheless, I am excited to see what New Horizons sends our way once it sends its signal later tonight.

One of its latest transmissions has already given us an amazing view of Pluto and Charon.

Pluto and its moon, Charon

The sun-side of Pluto

vonboy · **Reply #17 on:** July 14, 2015, 05:12:37 PM

Very nice pictures, Rhombus, and looking forward to more of them!

I'm thinking those black splotches might just be dust left over after some of the ice on the surface being melted off. It's a phenomonon seen on some comets, when they pass close by the sun.

It's been theorized in the past that during Pluto's closest orbit, when it's orbit drops past Neptune's orbit, it get's just enough heat from the sun to melt some of it's ice, and maybe even give the dwarf planet a temporary atmosphere. I wonder how this flyby's going to contribute to/disprove that theory.

Just babbling on my part.

Kor · **Reply #18 on:** July 14, 2015, 06:33:06 PM

Interesting color that Pluto and it's moon are. if that is ice i wonder what sort of ice it is. That bit about when it comes closer could be how if it has any ice, it may melt.

rhombus · **Reply #19 on:** July 14, 2015, 10:52:22 PM

New Horizons has sent a signal home, which means that it has survived the flyby. Furthermore, its log file indicate no anomalies, so this means that it had no logged problems in recording its data.

So hopefully we will be getting the first pictures from the flyby soon.