We're scientists on the NASA New Horizons team, which is at Pluto. Ask us anything about the mission & Pluto!

How close to true colour are the colour images returned so far? This image released today looks incredible, but is it true colour, or has the colour been exaggerated?

Yes it was true color! - Jillian

Yes, we tried to get it as close to real color as possible :). We combine the wavelengths that we have and translate it into what the human eye would see. ~Kelsi

Hello New Horizons team! Congratulations on a successful mission and thanks for doing this AMA. I’m so excited to see these images for the first time because I was born a few years after the Voyager II photos came in. I made this for everyone here!

Question 1: Can you talk about the snow on Pluto? If I were standing on the surface in a spacesuit while it was snowing, what might it look like?

Question 2: If you were to send a probe to Pluto, would it be a lander or rover, and is there a feature that pops out as a desirable landing site?

Cool! Yes, indeed, it is quite exciting and we are excited that people get to follow along with the discoveries! Most likely the frosts deposit pretty much directly on the surface, as the atmosphere is very thin - although it is possible that clouds could form, we haven't seen any yet! If there was snow, it would be quite frictiony, like skiing on sand, because it is sooooo cold there. It would not be like the snow on Earth, which is actually quite balmy compared to Pluto :). ~Kelsi

Hi and thanks so much for this gift to mankind!

I realized you guys were not bad at predicting how Pluto would look like. So I made this comparison: http://i.imgur.com/STEyAtF.png

How was that possible? I thought we knew almost nothing!

We have been observing Pluto and its largest moon, Charon, for decades. In the 1980s, a series of mutual crossings as seen from Earth took place and astronomers were able to map the different brightness regions of each body extremely well for such a far-off object. From those observations, and follow-up work by the Hubble Space Telescope, we have known that Pluto displays a largely contrasting surface. Based on that and the latest models, various space artists have drawn different renditions. --SJR

What is the most surprising thing you've discovered about Pluto since the mission began?

Charon's dark pole surprised us quite a bit.

-AZ

Why does the dark pole surprise us? Is there something scientifically unusual about it, or were we expecting it to match something else in the solar system?

We expected Charon's surface to be mostly uniform and featureless.

-AZ

Hello New Horizons team!

I wanted to ask if there was any chance of turning the New Horizons camera back towards Earth to see if we can pull another "Pale Blue Dot?"

Unfortunately, the LORRI camera is extremely sensitive, and looking back towards Earth would have the sun in the field of view and blow the instrument out. Voyager was able to do this because the instruments were on a platform that could move, and the engineers could orient it such that Voyager's dish acted as a sunshield. --SJR

I was born after the Voyager missions, and even though I was aware of other missions (to Saturn, to Mars), this is the first one to give me a tremendous sense of awe about how big the solar system is and about our ability to explore it. So thanks! :)

My question is this: my first daughter is being born in September, and I'm wondering what you think the first mission will be that will give her the same sense of wonder? What's coming down the pipe in the next 15-20 years or so?

What a great question! I remember holding my newborn son as the first Cassini radar data of Titan was downlinked in the middle of the night. The next big mission that can "grow up" with your daughter is the Europa mission. This mission will investigate if Europa and its huge global ocean is habitable. Take her to the launch in the early 2020's when she is ~8 years old, then watch the data come in with her when she is a young teenager. - Curt

We frequently hear that public interest in space programs has steadily declined since the moon landing. How does interest in today’s unmanned missions (such as New Horizons) compare to say something like the moon landing? And does the level of public interest factor into funding of these types of projects?

It's hard to make direct comparisons because the way the public can interact with the missions is so different now. Does live coverage of an event on national TV in the 1960's equate with websites and twitter feeds updating minute by minute? What I really love about our planetary science missions is that the public can ride along with us, and we want you to join us. These missions are YOUR missions. - Curt

My Mom says everything stopped back in the day, and all three TV channels covered it. Now, public interest is so fractionated. But people have better access to what is going on with the internet, and can quickly and easily learn a lot. It's an interesting trade-off.

-AZ

In the Magic School Bus episode Lost in the Solar System, Arnold removes his helmet on Pluto during an argument and his head is instantly frozen in a block of ice. Although this is obviously not what would happen, does any water ice exist on Pluto? Has the probe discovered more or less water than expected, or any water at all?

Some of us re-watched that episode earlier this month!

We haven't seen any water on Pluto yet, but if there is any water, we'll see it when we get our LEISA scans.

We've known about the water on Charon since the late 80s.

-AZ

1. What is next for New Horizons?
2. What do we hope to learn about Pluto?
3. What other information/pictures/data will New Horizons be sending back?
4. What has your day been like and what does it feel like to be part of the team?

Thank you so much for all your work. The significance of this is not lost on us, though I am still working at fathoming all of it.

1. Next is all of the data download. It will take ~16 months to download the amazing data.

2.We hope to learn about Pluto and its five known moons. The atmosphere, the geology, the composition of the rocks, and much much more.

3.New Horizons has seven instruments - ALICE, LORRI, PEPSSI, RALPH, REX, SDC, SWAP, so lots of data will be coming down in addition to the images you have seen already.

4.Today has been great. We all gathered and counted down to the closest approach. I can only imagine how exciting tonight will be when NH phones home.

--Jillian

Does New Horizons have the capability to find any undiscovered moons?

Also, my little girl has been fascinated with space since she was two. She ran in my office this morning "Daddy, can you show me pictures of Pluto today?" I loved having that moment where I could say "We've never seen it this close before ever" and watch a kid's curiosity get sparked by it. Thank you!

Yay! Happy to hear Pluto is inspiring the next generation :).
New Horizons does have the ability to detect new moons - we have been doing careful searches though all of the images and so far no luck. We will keep looking though, and even as we are departing we will look back at the Pluto system and that will be our best chance to see any faint diffuse material like rings. ~Kelsi

What are the first pictures we will see from New Horizons after the "phone home"?

The first image we should see after the "phone home" comes several hours later, what we call "C_LORRI_FULLFRAME." This will be very much like the image released this morning of Pluto, but it will be of the largest moon, Charon. --SJR

When are these pictures expected?

Tomorrow (US time).

What programming languages are used in the software onboard?

Assembly was the original answer but I was wrong and the great coders let me know what the real answer was. -Jillian

Speaking only of the spacecraft code, that was written in C using the Nucleus RTOS. I'd bet there was some assembly in the board support package and maybe some sprinkled here and there, but it the vast majority was written in C. The guidance and control algorithms were auto-generated C via Simulink. --Christopher Krupiarz, New Horizons Flight Software

A big hello to the New Horizons crew! You guys rock, sending a machine 2.9 billion miles away is an AMAZING feat. This is one of the last major objects to be studied in our solar system, and YOU are doing it! I do have a few questions for you, this is an IAMA after all!

1) What is the most interesting/shocking/surprising thing you have learned about Pluto and its moons so far?

2) What are you expecting from the data in the coming months?

3) I heard that New Horizons arrived at its destination 72 seconds early. How hard was it to get this close to the targeted time after 10 years, and will this change anything?

4) Have any problems occured at this point, and how did you tackle them?

And finally:

5) Will you be able to study the composition of Pluto's moons closely, and what do you think they'll be made of?

I'm sure the excitement of the New Horizons team is lightyears ahead of mine, and I hope everyone has a nice week without too many hiccups.

"To infinity... and beyond!" -Buzz Lightyear

For #3: It was hard. We have a great navigation team who worked tirelessly to make this work. We had a wonderful launch, a recent TCM that got us on track, and we are very happy.

For #4:We had an issue over the July 4th weekend. Many engineers and scientists worked over the holiday weekend to recover from the fault. --Jillian

I have been looking forward to this day for years - it's my birthday, too, so thanks NASA, for an awesome present! It's so exciting to be able to witness scientific history.

I have one question: will New Horizons be gathering any more data past the Pluto flyby, or will it just be focusing on transmitting the data it has already gathered?

Thanks for doing this AMA!!

Many observations are being taken during and around the closest approach to the planet and its moons. This includes observations of the night side as well as what we call "sliver" maps which are the very thin crescent images that the craft will see over the coming weeks. Sliver observations are planned through July 30. --SJR

Amazing. Do you know how much, if any, data from the Kuiper belt will be gathered?

The plasma and dust instruments will continue to gather data so long as they work and the mission is funded. They don't need to be near a planet to do interesting science. A mission to another Kuiper Belt Object is being proposed to NASA as an extended mission of New Horizons. --SJR

Happy birthday!!!!

-AZ

The latest images suggest Pluto’s surface is much newer than Charon’s, even though the dwarf planet and it’s moon are the same age. Are there any theories in the works about the resurfacing process and it’s cause?

There are two likely reasons, but forthcoming New Horizons' data will hopefully let us refine these or figure out a better reason. One is that Pluto is larger than Charon, so it can retain more heat and have active geology longer. Another is that Pluto has a tenuous atmosphere, and during the 248-year orbit around the sun, the atmosphere sublimates from one area in sun and is deposited in another in darkness, and then this reverses half-way through the orbit. This process is very slow, relatively speaking, but so is cratering. --SJR

Shortly after his discovery of Neptune in 1848, Urbain le Verrier said:

"This success allows us to hope that after thirty or forty years of observation on the new planet, we may employ it, in its turn, for the discovery of the one following it in its order of distances from the sun. Thus at least we should unhappily soon fall among bodies invisible by reason of their immense distance, but whose orbits might yet be traced in a succession of ages with the greatest exactness."

I want to congratulate you, @NASANewHorizons, on your greatest exactness!

My question has to do with how we classify these objects. Since Pluto and Charon orbit a shared point/barycenter in space, is it finally time to stop calling the latter a moon? Thanks to all of you, it seems to me that we have our first up-close, composite photograph of a binary dwarf planet!

...and if we continue with that line of thought, aren't Styx, Nix, Kerberos, and Hydra really scattered Kuiper Belt debris that fell into orbit around Pluto's system, as opposed to traditional moons?

It's exciting to wonder about these things. The Kuiper Belt seems so fun!

Many of us on the team refer to it as the "Pluto-Charon system," rather than a visit to "Pluto and its moon Charon," or words to that effect. For me, personally (Stuart Robbins), it doesn't matter what we classify these bodies as or call them: They're still really neat and we're learning about objects we've never visited! --SJR

Congratulations New Horizons team on today's flyby!

I know we won't get any new signals from the spacecraft until tonight, but based on all the pre-flyby data and images, what are the 3 things you are most excited to get more information about?

Three?

I'm most excited to see up-close images of "the whale" and "the heart", as well as LEISA spectra of those images to see what they are made of.

I'm looking forward to images of Hydra. With Pluto and Charon, we've gotten increasingly clearer images that have teased us. Hydra has been nothing more than a pixel or two, barely resolved. What it is like will be a complete surprise to us, though we have some suspicion. Ditto with the other small satellites.

I'm also looking forward to seeing the stereo mosaic we are doing of Pluto's surface, which will help us determine elevation.

-AZ

Hi, If you could go back in time and make modifications to the spacecraft, what would you change ?

Adding warp drive. - Curt

Hi NASA, First I would like to congratulate on great job that you've done! Question: What is the most exciting thing that you have discovered during this expedition New Horizons?

This is a hard question to answer because it changes every couple of hours. You can't pick your favorite Christmas present until you are done opening the presents, and we won't be done with that until all the data is downlinked in 16 months. Longest. Christmas. Ever. - Curt

So excited for this! My question is does Pluto have an atmosphere? And if so, what kinds of things can you determine about it?

Pluto does have an atmosphere! It is bit on the thin side, 10 microbars compared to Earth's 1 bar. It is ~98% N2, with trace CH4 and CO. We will be looking at its structure, and its composition - all sorts of good info will come from both the visual images from the LORRI images, and the Alice instrument. ~Kelsi

Hello New Horizons team!

I just want to say congratulations on the success of the mission and also a heartfelt thank you. I can remember being a little kid watching shows like Bill Nye the Science Guy and The Magic School Bus featuring the solar system and how little we knew about Pluto.

Pluto was my favorite planet growing up. I can remember the day it was "demoted" to dwarf planet and how disappointed I felt (now I'm an avid defender of its dwarf status).

How does it feel to finally see Pluto? What emotions bubbled up when you saw the first picture that you could actually make out what she looked like?

Also, if you have time. What scientific knowledge do you think we can gain from this? About Pluto, but also about our Solar System and other planetary systems?

I watched those shows when I was a kid too!

Seeing Pluto this morning was pretty great, but it made me feel curious, wondering how Pluto came to have its bright and dark areas, and why it's cratered the way it is.

We hope that seeing Pluto's surface (and Charon's) will give us a record of what went on in the Kuiper Belt, and more broadly, the remnants of the disk in which planets form.

-AZ

At what time did New Horizons make its closest approach to Pluto?

This morning, July 14 at 7:49am ET! - Jillian

Congratulations on one of the greatest achievements in the history of mankind. My question is how did you figure out the diameter of Pluto, did you use just trigonometry or something else?

Well, there is some trig, yes. We actually fit profiles to the limb of Pluto. Which is a fancy way of saying that we trace around the edge of Pluto, which provides us something close to a circle, and then measure how many pixels across that circle is. Since we know how many km per pixel, we can figure out the diameter in km by counting those pixels. It sounds straightforward, but the artistry comes in figuring out when you "stop" counting pixels (where the edge is) --Curt

Fascinating, but that also sounds like it is very open to interpretation, or am I just misunderstanding the process? Thank you for answering my question.

You're right, it is somewhat open to interpretation. That's why we have about 5 people do it independently of one another and compare results. And by "compare results" I mean we lock them in a cage together until a victor emerges. And we did that every day for 5 days. - Curt

Will we see detailed photos of Pluto's moons in near future too?

Charon, yes. Hydra, yes (tomorrow or Thursday!). Nix, perhaps, but not Styx nor Kerberos. --SJR

How long until the first high resolution pics?

We are getting data tomorrow! July 15th! That is higher resolution than anything we have ever gotten so far (~400 m/px and right now we have 4 km/px). We will get even higher the data takes a while to come back, so we probably won't get that back until ~mid-Sept. ~Kelsi

At 2015-07-15 19:00 UTC, New Horizon is shown spinning around scanning all of the sky with ALICE. Which looks hilarious at high speed. What science is being done there?

This observation is SKY_LYMAP! We are basically somersaulting 6 times, hence the awesome animation. - Jillian

Yours is truly one of the most gratifying expenditures of tax monies, and I speak for so many, when I say we're immensely proud OF you and FOR you right now. How can WE best encourage funding for THIS type of exploration? IS there any way the public an be more directly involved....funding, distributed computing, ANYthing?

Write your congressperson.

-AZ

Congratulations! =)

• Will information be gathered/transmitted once past Pluto, or does the mission end here?

• How do your findings compare to the team's original expectations?

• What is the most unexpected thing you have discovered so far since the "flyby" began?

Thank you!!

I think most people thought we would find at least one small moon - so far no new moons...!!

We will be taking lots of departing observations, really cool ones! We will be looking at the thermal structure (temperature) on the night sides of both Pluto and Charon - and we will be looking along the lit crescent of Pluto to see if we see any signs of atmospheric hazes or clouds. And we will also be trying to image the un-illuminate side of Pluto with charon-light. AND after all that we will be hopefully be getting distant observations of KBOs and also a closer flyby of one object - if NASA approves an extended mission. ~Kelsi

Congratulations on reaching Pluto! My question would be about hearth shape of Pluto. Do we have at least a theory on how it formed, and what is it made up from?

Thanks! You ask a great question that has one of the very favorite answers that scientists like to give: We don't know! You have no idea how excited scientists get when our answer is "I don't know." It ranks up there with the cogent observation "Well, that's weird..."

So no, we don't have any idea how that formed - yet!

• Curt

How does data get sent back to Earth from New Horizons? How long does it take for a photo to be received?

The light-travel time is about 4.5 hours at this distance. It takes over an hour for an image to be played back because of the very slow speeds over such a long distance. --SJR

Ok, super early to ask this, but:

Does the team have any idea of what the next Kuiper belt target might be, and how many more years it'll take to get there?

We're still working on deciding (but we are little busy at present :-P). We'll announce our decision in the fall, and then burn to that object shortly after. Even if we had decided already, we won't alter the spacecraft's course until the fall anyway, so there's no rush.

The timeline on both objects we are looking at put a KBO encounter at late 2018 or early 2019.

-AZ

Hello, Will we be seeing photos of the elusive Kerberos and Styx?

No, they were discovered too late. We will be observing them briefly but they will be close to point-like objects and we won't get that data for several months. --SJR

They will be points of light in the images. - Jillian

Congratulations New Horizons team! How old were you when the mission started? How old will yo be when last mission finish? Also, all the code of the ship is programed in some common language (C, C++)?

There are many of us on the AMA reddit in a room, so I'll answer for me: I'm 32 and so I was 22 when the probe launched. I was much younger when it was proposed and funded (18 when selected, younger when proposed). The mission is funded for another two years for science analysis (end of downlink (16 months) plus 6 months). An extended mission is being proposed to another Kuiper Belt Object.

The code on the spacecraft is written in Assembly. --SJR

I was 24 when I started on New Horizons in 2004. I will be ..hmm... older when it finishes. At least in my 50/60s when the power runs out.--Jillian

What were your predictions for the flyby back when New Horizons first launched in 2006? How are your findings different now?

There's an envelope of stuff Alan has and plans to open soon.

We also made another set of predictions this winter that I'm in the process of tabulating as our results come in. We've found that even experts can't predict everything perfectly.

-AZ

How much more expensive would it have been to send the probe into orbit around Pluto instead of a fly-by?

It would not be possible with current technology due to needing so much fuel at launch. --SJR

How has this mission made you feel in terms of "your place in the universe"? I realise this is an esoteric question but I wonder if you are experiencing the overwhelming fact that "the more you learn, the less you know". Science and space must be saturating your thoughts - and rightly so - but how has this incredible mission impacted on you as part of humankind?

That's a deep question, and sleep deprived people don't do well with deep philosophical questions! But this mission has really shown how far away from home our spacecraft is - Pluto is deep, deep out in the black. It will be years before the spacecraft reaches a KBO for a flyby, and then nothing, ever. It redefines lonely and helps you better appreciate your companions. - Curt

Hello! Thank you so much for doing this and all your awesome work. A couple of questions. First, when did we know for sure that Pluto was copper colored? Also, what's next realistically for New Horizons?

Thanks! Go New Horizons!!!

We had a good idea Pluto was copper, based on photometric color measurements, Marc Buie's maps and data from the mutual events.

Right now, we are finishing up taking the encounter images, then we are going to be sending data down. In the fall we are burning toward a Kuiper Belt object. If we get approved for an extended mission, we'll have a KBO encounter sometime in late 2018 or early 2019.

-AZ

I've heard Pluto is dark and cold, but could you live there when the sun is out?

At -370F, it's a terrible idea.

-AZ

What's the LORRI exposure time for the pictures taken in Charonshine?

We're using MVIC to study Charonshine on Pluto, but we're using LORRI to look at Plutoshine on Charon. We are taking over 100 observations of Charon at 0.2 and 1.0 seconds and then adding them together which is just about as good as a single long exposure, but it has the benefit of the spacecraft not needing to hold still as long. --SJR

Now that we have better pictures of Pluto, where would you say the best location for a penguin sanctuary would be?

Well, one of our team members really likes penguins. So ... his office? -AZ

Hey guys! Congratulations!

How's the atmosphere over there now? What's the next thing on your checklist?

We are all very excited. Next thing on our checklist is the phone home this evening at 9:07pm ET. - Jillian

What an amazing day! I got my new StarTalk t-shirt in the mail and got to watch the live broadcast this morning!

How long will New Horizons transmit data back to NASA? Can we potentially use it for additional research beyond Pluto?

At the datarate we have (2 kilobits per second) it takes over 2 hours to downlink a standard picture from your cell phone! That means we will spend the next 16 months transmitting all the data down to Earth. And yes, we are considering maneuvering the spacecraft so it flies by a small object farther out in the Kuiper Belt. - Curt

We're pretty excited too!

We will be getting back the data taken in July up through the end of 2016.

We'd like to fly by an object in the Kuiper Belt, we've narrowed it down to two.

-AZ

Why are there so few craters?

We see craters clearly for the first time in the image released this morning. We hadn't seen them prior to that simply because the pictures weren't sharp enough yet to show them. --Curt

(SJR Added--) We've seen craters on Charon as of about 1-2 days ago.

How does the New Horizons probe stay warm?

From reading specs, the probe is designed a bit like a thermos bottle to stay insulated and operate at room temperature, but what's the original heat source? Is it the same plutonium radiation that is used to power the probe?

Thank you!

We have others heaters that use some of the energy that the plutonium produces. - Jillian

What type of snacks / drinks do you guys keep on hand for long days working on this mission?

If you had a unlimited budget what would be your dream mission?

I'll answer the snack portion: I brought a lot of candied pecans, fudge, and cookies to share with the geology team. I also have been going to Costco every few days and supplying us with jelly beans, M&Ms, jerky, Oreos®, apricots, apples, dried fruit, pretzels, bagels, and chocolate-covered almonds. We get stragglers from other groups coming in to steal our food. --SJR

Hello Nasa, How far the New Horizon is anticipated to travel ?

New Horizons will never stop travelling. The power will last until about 100 AU (around 20+ years). -Jillian

How powerful is the computer inside the spacecraft?

The computer is a whopping 12 MHz. Yes, you read that correctly: 12 megahertz. People are always surprised at how much less powerful our flight computers are compared to their home computers. But we build them rugged. If you bolted your laptop atop a rocket, violently shook it, exposed it to vacuum, and had it endure temperature extremes and radiation, then your vacation pictures might be at risk. But ours will be just fine. - Curt

I'd like to echo the many words of support and congratulations here and all over the world this afternoon.

My question is this: Do you ever get discouraged by the seemingly misguided obsession with Pluto's status amongst the general public? It's already proven to be a fascinating object and system, and I can't help but wonder if you ever get the urge to scream, "Stop arguing and just look at all this cool new info!"

Edit: And one more question. I assume that technology has advanced quite a bit since the craft's launch in 2006, so are there any new instruments or methods that you wish had been available for implementation on NH?

To me, it really doesn't matter what it's called: It's a new body we've never explored before that we're seeing for the first time in a region of the solar system that we haven't explored with a craft with this kind of capabilities. I think the back-and-forth helps increase visibility and interest in the object, which is a win. --SJR

What data are your teams looking forward to the most to receiving?

we can't possibly choose because it is all exciting!! we will learn so much about the surface, the atmosphere, and the space environment around Pluto!! ~Kelsi

Hello Pluto team, congratulations on your historic conquest

Question 1: What were everyone's reactions in the control room after the flyby?

Question 2: What information have you received so far from New Horizons

Hey! as you can imagine we were quite excited! There is a spiffy video on the NYTimes.. :) http://www.nytimes.com/2015/07/15/science/space/nasa-new-horizons-spacecraft-reaches-pluto.html?_r=0 ~Kelsi

Hallo New Horizons team! Why the name Pluto? Gracias !:)

An English student Venetia Burney suggested it shortly after it was discovered.

-AZ

What are the technical specifications of New Horizons' storage system? How much data can it hold, and how many images (and other data) does that represent?

We have 8 GBs of storage on each recorder and we have 2 of those. We have to leave some space for compressing and other storage. It isn't a lot of room, so we have to choose wisely. We compress the data as much as we can to store as much as we can. -Jillian

Congratulations to the New Horizons Team, JHU/APL and SwRI for achieving this great feat. I have been super excited about this flyby since a couple of months, and was constantly checking the Twitter feed for updates since morning. I was awestruck after looking at the latest image of Pluto. Some of things and questions would like to ask to you guys are:

• New Horizons is moving pretty fast ( ~16km/s), it made it's closest approach at ~12,500 km which was for a very short period of time, I read somewhere that it was around just 8 minutes and now the distance from Pluto is increasing again. I want to know why didn't the team made the decision to slow down NH for a bit, so that it can collect more data, and more images. Was it possible to do that? And if yes, how would that decision had effected this mission or health of the space probe?

• There are less craters on Pluto's surface as compared to other solid bodies in Solar System, how and why and what are your thoughts on that?

• Is there an atmosphere on Pluto? What's its composition?

Thanks for doing this.

Thanks, we really appreciate it. We worked really hard to speed up as fast as possible - biggest rocket possible and a gravity assist from Jupiter, the largest planet. Slowing down would be equally difficult - it would take a HUGE amount of fuel to slow down appreciably.

We didn't really start seeing craters until the image released today - the pictures simply weren't sharp enough till now. The images that come down later this week will be better for crater counting, and then we can compare to other planets.

And yes, Pluto has an atmosphere! It is very thin, even thinner than Mars (which is about 700 times thinner than Earth's). It's the kind of atmosphere only a scientist could love. And we think it is mostly nitrogen, but a big objective of the mission is to learn more about it. - Curt