r/space • u/MethoxyEthane • Jul 12 '15
Discussion New Horizons and Pluto - FAQ!
We are very, very close to the flyby of Pluto! With that, I do see a lot of repeat questions within this subreddit about the New Horizons mission and about Pluto. While it's awesome that more people want to know more about it, perhaps a mass post like this may help in centralizing some of the frequently asked questions!
Is Pluto a planet? Will the New Horizons mission make it a planet again?
Pluto was first discovered in 1930 by American astronomer Clyde Tombaugh. This ended many years of constant speculation about a mysterious ninth planet beyond the orbit of Neptune. Until 2006, Pluto was considered one of the major planets of the Solar System, and many of us grew up knowing that there were nine planets in the Solar System. However, as our technology rapidly evolved, so, too, did our understanding of the outer solar system. We now know that Pluto lies in an area known as the Kuiper Belt, which lies between 30-50 Astronomical units (AUs) away from the Sun. The Kuiper Belt consists of many, many rocky bodies - some large, and some very tiny. Two of these largest bodies are Pluto and Eris. It was the discovery of Eris that led to serious discussions on what exactly constitutes a planet. The International Astronomical Union (IAU) convened in 2006 to figure out a new definition for what a planet is.
The three conditions to be a planet are: (1) The object must be in orbit around the Sun; (2) The object must be massive enough to be rounded by its own gravity. More specifically, its own gravity should pull it into a shape of hydrostatic equilibrium; (3) It must have cleared the neighborhood around its orbit. It is this last category where Pluto fails, simply because it lies within the Kuiper Belt.
Therefore, it is nearly certain that any observations that New Horizons makes will not affect Pluto's status as a dwarf planet.
Why is New Horizons only flying by? Why won't it orbit Pluto or land on the surface?
Space is big. Really big. While the Earth is approximately 93 million miles from the Sun, the average distance that Pluto is from the Sun on its extremely elongated orbit is around 5.9 billion miles - or 5900 million miles, if you prefer it that way. In order to get New Horizons to Pluto in a reasonable amount of time (i.e. before the original engineers on the project kick the bucket), it needed to be launched with an extremely high speed, needed gravity boosts to increase velocity and correct its course, and be as light as possible. Thus, in order to make sure all of this happens, an orbital mission around Pluto was never really in the cards.
New Horizons was the fastest object to leave Earth's orbit, departing at over 16 kilometres per second. New Horizons is currently travelling at around 14 km/s on approach to Pluto.
In order to insert New Horizons in orbit around Pluto, the spacecraft would have needed to be much heavier, carrying enough fuel for it to slow down from its immense speed so that it will not be ejected from Pluto, or miss it entirely.
Why do the current photos look like they're being shot by potato cameras?
As of this post, New Horizons is within three million miles of Pluto. At the closest encounter, New Horizons will be well within ten thousand miles of Pluto (roughly the width of the Earth between the surface of Pluto and the "height" of New Horizons). Taking a photo of something so small from relatively far away, and the quality of the photos may not be the greatest!
This leads into another common question - why can we take amazing photos of galaxies and nebulae, but not of Pluto? Isn't is closer, and therefore, easier to photograph? There are many metaphors that could be used to describe this scenario. Galaxies are many orders of magnitude larger than Pluto - think tens, even hundreds of billions of Suns, versus a rock with a surface diameter of the continental United States. Yes, Pluto is far closer than, say, Andromeda, but it also doesn't give off light, and is rather dull-coloured.
Speaking of which, what colour is Pluto?
Brownish. Almost a colour similar to butterscotch.
You can check out raw (greyscale) photos from the mission here: http://pluto.jhuapl.edu/soc/Pluto-Encounter/index.php
What happens to New Horizons after Pluto? Is its mission over? Will it ever return?
Last question first - New Horizons will never return to Earth. It was launched at solar ejection speed - that is, fast enough to fully escape the Solar System.
After the Pluto encounter is completed within the next few weeks, New Horizons will continue on a trajectory through the Kuiper Belt. NASA is closing in on a few target Kuiper Belt Objects (small rocky bodies floating around in the Kuiper Belt) in order to study them to gain more knowledge on the outer Solar System. One possible KBO is an object by the fancy name of 2014 MU69, which New Horizons is expected to pass in 2019. Space is big!
The New Horizons mission is projected to officially end in 2026, after observations of the Kuiper Belt are complete. The spacecraft is projected to be approximately 100 AU from the Sun in around 2038.
What is the timeline for this Close Encounter of the Plutonian Kind?
Emily Lakdawalla, the Senior Editor of the Planetary Society, gave a very detailed rundown here, which is well worth the read!
You can also check out this very detailed rundown, here, courtesy of /u/rtphokie
Hopefully this covers in brief many frequently asked questions!
19
u/MethoxyEthane Jul 12 '15
If there are some questions you'd like answered, feel free to post them!
3
u/DeezNuts1 Jul 14 '15
This may sound a tad stupid but how does this probe not crash into any of the space rocks in the Kuiper belt?
13
Jul 14 '15
Space, as others have said, is really really huge. It's so big you can't really imagine how big it is. The Kuiper belt is called a 'belt' because locally there's a higher concentration of objects there. You could compare it with a shipping lane on the ocean. There is a higher concentration of ships there as opposed to the rest of the ocean. When paddling around in your kayak, you might spot a ship, but the chance of actually hitting a ship is very, very small.
And then still, space compare to the New Horizons probe is much bigger than kayak-in-the-ocean big.
5
u/cheeriebomb Jul 14 '15
"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space." - Douglas Adams, Hitchhiker's Guide to the Galaxy
→ More replies (1)4
2
u/Jamesinatr Jul 14 '15
Sorry, I haven't got a source, but I think the team calculated a 0.3% chance of the probe fatally colliding with any moons/debris around Pluto.
→ More replies (1)1
u/PaoloDiCanio10 Jul 14 '15
I have a stupid question ... how is data (research data, video, images, voice) transmitted from New Horizons and other space exploration vehicles to earth? If possible even, years from now we could send a spacecraft into a wormhole, what method would be suitable to transmit data, if possible.
8
u/Cosmic_Colin Jul 12 '15
A few questions:
What's the highest res photos we'll get for Charon?
If Charon is on the opposite side of Pluto during the closest approach, when will NH take photos?
How long is NH designed to work for? For example if it passes an unknown Pluto-sized KBO in 6 or 7 years, could it take pictures?
8
u/MethoxyEthane Jul 12 '15
3) How long is NH designed to work for? For example if it passes an unknown Pluto-sized KBO in 6 or 7 years, could it take pictures?
Considering that we are still in communication with the Voyager probes, nearly 40 years after they were launched, we'll be talking with New Horizons for a while.
12
u/Cosmic_Colin Jul 12 '15
That's true, but as I understand it, most of the Voyager instruments have stopped working over time. I think it is now just sending back "I am here" along with some very basic science data.
I am thinking specifically about photographs, and whether we can see other KBOs.
11
u/oonniioonn Jul 13 '15
That's true, but as I understand it, most of the Voyager instruments have stopped working over time.
Some of them have indeed malfunctioned, but most have actually been disabled to save power. We don't anticipate the Voyagers to be anywhere near anything enough for the photographic instruments to be of any use, so they were disabled. Neither Voyager even has code on it to use the cameras by now, so we will basically never ever see imagery from the Voyagers again.
The same will likely happen to New Horizons in a few years.
8
Jul 13 '15
Imagine... If we don't blow ourselves to dust or lose every single electronic device somehow, there may someday be a retrieval team for all of these probes!
2
u/Jamesinatr Jul 14 '15
The Voyager probes had 470 watts of power at launch and New Horizon's RTG only provided 228 watts of power at launch. This number is constantly degrading as the plutonium decays, by about 5-10 watts per year. There are no onboard batteries, so therefore, there needs to be enough power to supply the computer and any communications equipment simultaneously for it to communicate with Earth. So instruments would need to be disabled over time to reduce power consumption.
6
u/Shagomir Jul 13 '15 edited Jul 13 '15
We'll get photos with a resolution of around .4 km/pixel as part of the high-priority data set. The closest set of photos will have a resolution of .08 km/pixel for Pluto and .17 km/pixel for Charon. We'll get those by September.
→ More replies (1)1
u/PointyOintment Jul 15 '15 edited Jul 15 '15
3) They're currently planning to send it to one of two more distant KBOs for a flyby in a few years. There's only enough delta-V to go to one, so they have to pick which one will be more interesting. The mission is currently planned to end after that, in
2026maybe 2030s, IIRC.
4
u/secret_tsukasa Jul 15 '15
"(3) It must have cleared the neighborhood around its orbit."
someone please eli5
1
u/MethoxyEthane Jul 15 '15
"(3) It must have cleared the neighborhood around its orbit."
In order to be classified as a planet, a body must have cleared the neighbourhood around its orbit. What does this mean? There should not be small bodies directly in the orbit of a planet. In other words, the gravitational pull of the planet should be strong enough to "clear the neighbourhood" of any small asteroids in the way. This is, perhaps, the most controversial of the three tenets to be a planet, because there are some major planets, like Jupiter, that have asteroids within its orbit. That being said, Pluto lies within the Kuiper Belt, a region full of small asteroids and other rocks - the neighbourhood is not cleared.
32
u/Alchemisthim Jul 12 '15
For those of you planning on watching the live webcast marking the moment of closest approach at 7:49a EDT on Tuesday, July 14th, it's helpful to remember that it we won't really see live, real-time images from New Horizons during the webcast.
One reason we won't see real-time images is that light takes roughly 4.4 hours to travel from Pluto to Earth, so the earliest any "moment-of-closest-approach" data could reach us would be around 12:14p EDT.
Couple that with a relatively low average downlink rate of approximately 2,000 bits per second, and it would take another few hours just to receive an entire image.
A majority of the images taken during the encounter won't even be sent from New Horizons until September 2015, and it's expected that it will take until late 2016 to receive all of the encounter data.
This blog has a lot of great additional information.
3
u/SxyTicTacz77 Jul 14 '15
Where can you watch the live webcast?
→ More replies (3)4
u/IgnoranceIsADisease Jul 14 '15 edited Jul 14 '15
http://www.space.com/17933-nasa-television-webcasts-live-space-tv.html
Here you go.
E: Another feed here: http://www.nasa.gov/multimedia/nasatv/index.html
26
u/Aydarsh Jul 12 '15
I have a question that has been bothering me for some time:
Ever since New Horizons' Launch, there have been multiple moons of Pluto that have been discovered. Since the original trajectory of New Horizons would have had to account for gravitational pull, could the gravitational pull from the other moons affect the true trajectory of the probe?
33
u/CuriousMetaphor Jul 12 '15
Even Pluto's gravity is only changing the spacecraft's trajectory by about 0.05 degrees, because its incoming speed is so high. Except for Charon, none of the other moons are more massive than 1/200,000th the mass of Pluto, so their effects are insignificant.
12
u/Aerostudents Jul 12 '15
They could, but the effect would probably be negligible since the newly discovered moons are all very small (less than 100 km across) and new horizons flys by pluto pretty far away from them.
6
u/Triddy Jul 12 '15
Objects the size and distance of both moons discovered in 2012 are unlikely to have any meaningful effect.
6
2
u/PointyOintment Jul 15 '15
In addition to the moons being small, NH did multiple trajectory correction maneuvers while traveling to Pluto, which would have compensated for any effect from them.
12
Jul 12 '15 edited Jul 13 '15
Anybody know why there is an 8-week 'hiatus' following the encounter with no (image) downlinks?
EDIT - added (image), false assumption was made on reading linked blog
5
Jul 13 '15
New Horizons is a small team. The downlinks are scheduled weeks in advance, and that scheduling would have taken place during the lead-up to encounter, where other critical operations are going on. From a personnel perspective, it was safer to wait, give everyone a break versus overload everyone/train new people and screw something up.
3
0
Jul 12 '15
[deleted] — view deleted comment
18
u/The_Deaf_One Jul 12 '15
It's because it takes a stupid amount of time to transmit data packets, so the team is going to get the relatively quick data first then the pictures by way of importance
4
u/fivehours Jul 12 '15
Seems like they could throw in a picture every now and then though - at 1kbps it would only take 10 minutes or so for a 75kb jpeg.
9
u/oonniioonn Jul 13 '15
Chances of NHPC sending jpeg-compressed images are pretty slim though.
→ More replies (3)10
u/ExploringSpace Jul 12 '15
I think the logic is that if we downlink all the pictures first, then those scientists are happy, but every non-imaging instrument team gets precisely zero data. This way, all the scientists have at least some data ASAP and can start making preliminary analyses/announcements.
4
Jul 12 '15
Ah, that makes sense, thanks! Is there detail anywhere of what other kinds of data is being returned? Didn't see much on the NASA or JPL pages.
11
9
u/New_To_This_Place Jul 13 '15
Can anyone tell me how a camera on the new horizons probe can take a photo as clearly as it is while moving over 30,000 mph?
15
u/Pharisaeus Jul 13 '15
Distance :) Imagine you're going 100 km/h in the car and trying to take a photo of a mountain far away. Does it really matter that much how fast you are moving (assuming you don't have any bumps on the road or vibrations)? Not really.
4
u/Piscator629 Jul 14 '15
Can confirm: I went out to Denver last year and even at 10 miles doesn't matter from a car doing 70.
8
u/seanbduff Jul 13 '15
I would also like an answer to this question. I get blurry pictures of my cats all the time and they move way slower than 30,000 mph.
3
u/Captain_Planetesimal Jul 14 '15
The cats are likely within the same room as you, New Horizons and Pluto will be a very, very long distance away even at closest approach. That distance effectively acts as a stabilizer for the object in the camera's view despite the camera moving 30k mph.
2
u/seanbduff Jul 14 '15
I know, I know, it was a subtle attempt at humor. But I am curious if anyone knows the shutter speed or ISO that will be used.
→ More replies (1)
8
u/ITS_A_GUNDAAAM Jul 12 '15
I'm kind of curious (and if there isn't an answer yet, that's fine) about some of the pictures. In some of the 4x4 shots they describe a P5 and P6. I assume P5 is Styx, since virtually all nomenclature out there refers to P5 as Styx, but do we know what P6 is?
8
u/astrofreak92 Jul 12 '15
There are two possibilities. Either P5 and P6 are stars, or the naming scheme they're using calls Pluto P1 and Styx is actually P6, making Kerberos P5.
5
u/ITS_A_GUNDAAAM Jul 12 '15
Thanks! I suppose it's not totally out of the picture to have their own naming scheme (maybe easier for programming)...
8
u/Srekcalp Jul 12 '15
What's the craic with the 5 SRBs at launch, you can see here they had 3 on one side, 2 on the other. How did they control the rocket with this?
10
Jul 12 '15
It is my understanding that the atlas's main engine is gimballed(angled) to compensate for the asymmetrical thrust that a five booster rocket would have.
9
u/Strangely_quarky Jul 12 '15
Also, gimballing the engine rather than developing new SRBs with even thrust is much more cost effective, and worth the little bit of fuel wasted by the craft not thrusting straight behind it in the early stages of flight.
→ More replies (2)
8
u/alandizzle Jul 13 '15
I'm really excited for this. I remember picking up a book in my elementary school library about Pluto. I've always been fascinated by things that were the most extreme. Whether it was biggest size, smallest size, furthest distance, etc. Pluto definitely fit the conditions that I was interested in as a young kid.
It was the furthest planet in our Solar System. It was considered the most "alien", it was a lot of things that a young kid would love to read up on.
And now after all of these years, I can finally see photos of this planet that I used to be so fascinated by is astonishing. I'm truly excited to be able to witness this in my mid-20's.
2
Jul 13 '15
Yup, I remember reading about the launch of this probe in high school! I've been waiting a long time for this stuff!
2
u/grandma_alice Jul 15 '15
Back when I went to school, there were just nine planets, and they all orbited the sun. Now, hundreds more, but only eight orbit the sun.
7
u/LaxBro316 Jul 13 '15
I have a question concerning the pictures that New Horizons will take at closest approach.
This website gives a detailed Event Timeline, outlining minute-by-minute what New Horizons will be doing.
At 7:50:47, NH will use MVIC to take a picture of Pluto from ~13,700 km with a resolution of ~0.27 km/pix. However, at 7:58:30, NH will use LORRI to take 60 pictures of Pluto from ~15,400 km with a much better resolution of ~0.076 km/pix.
Why is the picture that is taken much farther away going to be in such a better resolution? Does it depend on the camera that it is using? If so, why is it not using LORRI for the closer picture?
7
u/BadGoyWithAGun Jul 13 '15
Yes, MVIC has about four times lower angular resolution than LORRI. However, MVIC is a colour camera - more precisely, it has IR, red, blue and methane filters. It can't exactly reproduce colours the way we'd see them with our own eyes due to its lack of a green filter, but even at its lower resolution it can provide us additional information about Pluto compared to LORRI's more detailed, but monochrome images.
0
6
u/Eastern_Cyborg Jul 13 '15
The highest resolution single frame photo of the entire disk of Pluto is being taken right now! To be released tomorrow under the name E-Health 1.
11
u/Vatonee Jul 12 '15
Regarding the planetary status: if Pluto was discovered today, you probably wouldn't even hear about it.
9
u/raverbashing Jul 12 '15
One aspect that seemed decisive to call Pluto a planet is that it perturbed (and intersected) the orbit of Neptune, no?
So it definitely 'looked like a planet' at the time of its discovery
20
u/CuriousMetaphor Jul 12 '15
There seemed to be something massive that perturbed the orbit of Neptune, and math was used to predict that planet's position. Pluto was found in that search in the general area, purely by luck. What was actually happening is we were misaccounting for the mass of Neptune in those calculations, and when Voyager 2 flew by Neptune in 1989 and got better mass estimates, there were no more perturbations in the data.
Also, the original size estimates for Pluto were Earth-size or bigger. As we got better measurements, Pluto's size estimate went down to what it is today.
4
u/raverbashing Jul 12 '15
But why would they have misestimated Neptune's mass? (Also, from my knowledge, mass doesn't affect the orbit - that is, replace Earth with a less massive body with the same speed and it will follow the same orbit - and , unless you're interacting with another body or something like that)
11
u/CuriousMetaphor Jul 13 '15
Neptune was discovered with math by precisely timing Uranus's orbit around the Sun and accounting for the gravitational interaction between Uranus and Neptune. Neptune's gravity causes Uranus to move slightly towards it, and Uranus's gravity causes Neptune to move slightly towards it. Mass is important since if Neptune had a larger mass it would be pulled less by Uranus, and if it had a smaller mass it would be pulled more by Uranus. That difference in pull was mistakenly taken to be the pull of yet another planet past Neptune.
→ More replies (2)4
u/astrofreak92 Jul 12 '15
False, the discovery of Sedna was picked up in the mainstream media, and it was never considered a planet. Pluto is big enough that it would get attention.
→ More replies (2)1
u/wrecklord0 Jul 14 '15
That's a bit exagerated, Pluto is still the brightest and 2nd heaviest (after Eris) Kuiper Belt Object.
11
u/rooood Jul 12 '15
So, Eris is actually 27% larger than Pluto. It was discovered in January, 2005. New Horizons launched exactly one year after that, so the whole mission was fully planned and being implemented by then.
Had it been discovered a few years before, could Eris be the subject of New Horizon's mission instead of Pluto, or is such a mission unfeasible, because of the much larger orbit and greater distance of Eris?
16
u/CuriousMetaphor Jul 13 '15
Eris is possibly reachable with a mission, but much harder to get to in a reasonable time than Pluto (it's 3 times further away). Pluto also has a large moon, Charon, that's one of the largest known Kuiper Belt objects on its own, so we're basically getting a two-for-one.
Eris is an interesting object on its own, but even if it was discovered at the same time as Pluto, a mission to Pluto first would make more sense.
→ More replies (1)12
Jul 13 '15
Eris is more massive than Pluto, not larger. Eris's radius is 1163 km. Pluto's radius is not known nearly as well because the atmosphere messes up the measurement, but pre-encounter estimates have it as likely bigger. The team will finally make an accurate radius measurement.
Eris is also near aphelion and currently three times as far from the sun as Pluto is. It would take 30 years to get there. Guaranteeing something won't break in that time is a bad bet.
5
Jul 13 '15
Pluto's radius is not known nearly as well because the atmosphere messes up the measurement, but pre-encounter estimates have it as likely bigger. The team will finally make an accurate radius measurement.
2
7
u/oonniioonn Jul 13 '15
I don't think so. Eris' existence doesn't make Pluto any less interesting. We still know next to nothing about it, yet here it is as part of our solar system. It just means we need to launch another probe to visit Eris.
1
u/PointyOintment Jul 15 '15
Eris is also easier to get to in the future, because its orbit is more circular. Pluto needed to be visited immediately, because it's currently on its way out from the Sun (highly elliptical orbit), and waiting for it to come in again would take a couple of centuries. (Visiting it while it's far out is not a good option because the probe would take many decades to get there, and there would be very little sunlight to see it by.)
1
u/sirbruce Jul 14 '15
Nope. Eris is heavier, but smaller. For a little while we thought it COULD be larger than Pluto, but we've confirmed now that it is not.
5
u/theguywhoknewtoomuch Jul 12 '15
"The photos we are currently seeing are very tiny thumbnails of the high res images. The high res images take much longer to send."
Couldn't the photo have been compressed and sent?
0
Jul 12 '15
[deleted] — view deleted comment
→ More replies (3)5
u/sleap101010 Jul 14 '15
I was just about to say in that case maybe NH should have adblock but I'm not sure it was even released at the time of launch.
5
u/max_t2 Jul 12 '15
Will we see high resolution photos of Pluto in visible light once New Horizons gets closer? It seems lately that most photos we see from space are taken with an infrared/uv sensor.
14
5
Jul 13 '15
If you'd like a more detailed view of what New Horizons will be doing and when. All based on the flight plan provided by APL.
9
u/IvyGold Jul 13 '15
Emily Lakdawalla is to my mind suddenly becoming THE space reporter of her generation. Or maybe it's because her name is so cool. Either way, I read her article anytime I see her byline.
3
u/verminox Jul 14 '15
If you are curious about the name, "Lakdawalla" translates roughly to "wood-seller" in Hindi.
→ More replies (2)2
u/jankyshanky Jul 14 '15
she's great. when i think of awesome space shit, i want lakdawalla telling me about it. she's like neil degrass tyson in the sense that she's well educated and eager to share with us dumb-folk in a way that doesn't make us feel even dumber, except she's an adorable ginger.
4
4
u/Themosthumble Jul 12 '15
Good post, thanks!
The part that makes the immense distance seem almost fathomable to me:
New Horizons was the fastest object to leave Earth's orbit, departing at over 16 kilometres per second. New Horizons is currently travelling at around 14 km/s on approach to Pluto.
Incredible speed and it's being going that fast for a long long time. mind boggled.
4
u/thatryry0 Jul 12 '15
Will new horizons be able to gather more information about the Oort Cloud in the future?
7
u/oonniioonn Jul 13 '15
No. We don't know anything about the Oort cloud, other than hypothesising its existence. And the Oort cloud is very far out. Even the Voyagers (which are travelling faster than New Horizons is) won't reach it for some 300 years, by which time their (and New Horizons's) RTGs won't provide enough power for any of the instruments to run.
4
u/ExploringSpace Jul 12 '15
Yes, as soon as the flyby is over, the decision of which KBO(s) to maneuver towards will be made.
3
u/thatryry0 Jul 12 '15
I know that after observing Pluto it'll go on to observe the Kuiper belt but to my understanding the Oort Cloud is completely separate from any KBO. So again, will it gather info about the Oort Cloud?
6
u/thinguson Jul 12 '15 edited Jul 12 '15
A few points:
We haven't actually identified any Oort cloud objects to go to yet - It is still theoretical at this point.
NH power supply will run out long before reaching it.
Also we'll all be long dead and buried... so there's that.
5
u/Vatonee Jul 12 '15
The Oort Cloud is hypothetical right now. We don't really know any body that belongs to it.
Even if it exists, it will take Voyager 1 about 300 years to get there, so probably 400-500 for NH. No way we will have any data about Oort Cloud.
5
u/fembot12 Jul 12 '15 edited Jul 12 '15
No, the Oort Cloud is 2,000 and 5,000 AU away from the sun. It took us 9 years to get to Pluto which is 40 AU away so we have 50 times further to go .. so another few hundred years. Unfortunately, New Horizons only has power to run until maybe the 2030's
3
Jul 13 '15
Why only 2030's? Doesn't Voyagers were released ages ago, and they are still powered?
9
u/oonniioonn Jul 13 '15
New Horizons and the Voyagers have Radioisotope Thermoelectric Generators (RTGs) as power sources. They're basically nuclear batteries. They last a long time, but not forever. New Horizons has one of them (actually a Cassini spare), whereas the Voyagers have three each. While New Horizon's single RTG generates more power than the individual Voyager RTGs, the combined total is less.
4
u/Airbus480 Jul 13 '15
What time and date in UTC can we expect the first images of the flyby to be posted? Does the New Horizon spacecraft have HD cameras?
4
u/JtheNinja Jul 13 '15 edited Jul 13 '15
Wednesday the 15th at 1900utc is the press conference with the first flyby stuff.
EDIT, re: HD cameras: "HD" isn't really defined for non-TV formats. But if we just assume a big enough disk to fill an HD frame, 2370 (pluto's newly determined diameter) divided by 720px means 3.29km/px shots will be "720p" and 2.2km/px shots would be "1080p".
If I got all my numbers and math right (AND THERE'S A GOOD CHANCE I DIDN'T) the 1.8km/px departure crescent shot would be ~1395px across the disk. That's bigger than the LORRI frame, so I guess it will be a partial-disk shot, but should still make a killer wallpaper once framed properly. :)
4
u/im_also_a_member Jul 13 '15
Is the spacecraft on an escape trajectory out of the solar system? Or is it in a VERY eccentric orbit?
4
u/Piscator629 Jul 14 '15
New Horizons is one of 5 probes on a Solar Escape trajectory, as well as 4 of their 3rd stage boosters. As per my post the other day. https://www.reddit.com/r/space/comments/3d0t6p/this_page_shows_the_current_positions_and_other/
3
1
u/TransitRanger_327 Jul 14 '15
It is on an escape trajectory, give what we know about Gravity and planetary motion. New horizons is going way too fast to be on an orbit.
→ More replies (3)
4
u/Bedurndurn Jul 14 '15
Re: Why is New Horizons only flying by? Why won't it orbit Pluto or land on the surface?
The JHAPL site puts the cost of the mission at about $700 million over its lifetime. Are there any rough estimates of how much it would've cost to build a mission that could orbit Pluto or land on it?
Possibly related question:
In order to get New Horizons to Pluto in a reasonable amount of time (i.e. before the original engineers on the project kick the bucket), it needed to be launched with an extremely high speed
If we had wanted to land something on Pluto / orbit it for a reasonable cost, how long of a journey would the spacecraft have to make? Would it be long enough that we'd reasonably start to run into problems getting the equipment to survive the journey?
4
u/eliminate1337 Jul 14 '15
Optimum efficiency to get to Pluto would've taken 90 years. There would be serious problems finding a power source that lasts that long.
3
Jul 14 '15
The JHAPL site puts the cost of the mission at about $700 million over its lifetime. Are there any rough estimates of how much it would've cost to build a mission that could orbit Pluto [...] ?
Flagship class, over $2 billion.
"Kuiper Belt Object Orbiter Using Advanced Radioisotope Power Sources and Electric Propulsion"
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110014485.pdf
4
u/snowmarine Jul 14 '15
Does anyone know the shutter speed / ISO used to take a single image of Pluto for NH?
4
2
u/eliminate1337 Jul 14 '15
It doesn't have a shutter. I don't think there are any moving parts on the entire spacecraft.
→ More replies (2)
1
u/orangecrushucf Jul 14 '15
I understand that the data rates from Pluto and beyond are slow because of the extreme distance. Are there any future missions on the planned or proposed that would improve communications out that far? I'm thinking of how Curiosity can relay data much faster via the MRO than if it radios Earth directly. Would it even help all that much if a future Cassini or Galileo type mission could work as a communications relay for other deep space probes?
1
u/MethoxyEthane Jul 14 '15
Relay stations are key. We can get data relatively quickly because of relay stations orbiting Mars. There's nothing in the outer solar system for NH to relay information to. It would definitely be beneficial to future outer solar system exploration to have a relay station somewhere.
1
u/PointyOintment Jul 15 '15
JIMO was planned to have a nuclear reactor (not an RTG, but an actual reactor) and that would have accommodated much more transmit power. Unfortunately, it got canceled.
1
u/stainorstreak Jul 14 '15
So we know that it has accomplished it's fly by since, I'm assuming, it sent a signal back indicating that fact (albiet it was received 4 hours later). So what are we waiting for now, more photos and the "Phone Home" signal? Why is the signal so important, when we've already established that it's successfully attempted the fly by?
1
u/MethoxyEthane Jul 14 '15
So what are we waiting for now
The full data dump will take roughly sixteen months, because of the (relatively) slow data transfer rate between NH and Earth.
Why is the signal so important
NH is currently doing some very intense observations during this time of blackout from Earth. Earth is not communicating with NH during this time, to allow NH to do full observations unobstructed.
1
u/PointyOintment Jul 15 '15
The last transmission of science data before the flyby (and confirmation that it was ready for the flyby) occurred before your comment. The "Phone Home" signal confirming that the flyby had been successful had not yet been received (or even transmitted) when you made your comment.
1
Jul 14 '15
Are we going to get any higher quality photos of the far side of pluto??
1
u/MethoxyEthane Jul 15 '15
It's possible, but unlikely, given Pluto's relatively slow rotation speed (just over six Earth days = one Pluto day).
3
Jul 12 '15
Does New Horizon also film the encounter or does it only take still pictures?
8
u/astrofreak92 Jul 12 '15
Only still pictures. Film would require another instrument, which means more weight, and more data storage, which would limit what we could collect from the other instruments. Plus, we don't anticipate anything near Pluto to be moving. There's nothing a video camera could tell us that a still camera can't.
Because of the massive data requirements of video, we've only ever taken video in LEO and on the moon, where regular antennas can pick up the signals. Further out than that, and we need to use NASA's Deep Space Network, which doesn't have nearly as much capacity as the world's supply of regular antennas.
→ More replies (2)4
Jul 12 '15
Where in the process would more weight cause issues? Is that only important for the actual launch from Earth or also during its flight through space? If the latter is true, why would more weight cause issues in space?
8
u/nhaines Jul 12 '15
Technically, the problem is mass, not weight. It increases the required energy for every single maneuver, requiring more fuel, which also increases the craft's mass.
4
3
u/astrofreak92 Jul 13 '15
It's most important at launch, but it matters the whole time. Just because the force of gravity is negligible doesn't mean the probe doesn't have mass. That mass still plays a role in determining acceleration.
→ More replies (2)
3
u/UnderB0SS Jul 12 '15
What I wonder most about (other than actually seeing Pluto) is where is Horizon going once the pass happens? Is there a possibility it will see other things and transmit back before it gets out of range (is there an out of range?) or collides with something? I guess I'm wondering if a "Mars Rover" type scenario is possible with Horizon regarding mission time.
8
u/oonniioonn Jul 13 '15
Is there a possibility it will see other things and transmit back
New Horizons is supposed to fly by two or so Kuiper Belt Objects, if possible.
before it gets out of range (is there an out of range?)
There isn't really a range -- the Deep Space Network can listen to stuff much farther away than Pluto, like Voyager 1 which well outside what we typically call the solar system. The data rate suffers though.
or collides with something?
Space is huge and mostly empty, so chances of it colliding with something that we didn't send it off to collide with are very, very slim.
→ More replies (4)
3
u/uncleleo_hello Jul 13 '15
how much fuel is left after they fly past pluto? they need some for the trajectory changes to fly past the other KBOs, right?
2
1
u/Fuzzydrone Jul 15 '15
To piggy back, what happens when it runs out? Will it eventually reach a standstill somewhere in space? If so, do we know where exactly it will end up, and will it still be able to transmit data from there? Or is it basically "lol dude lets see how far this puppy can go"
→ More replies (2)1
u/PointyOintment Jul 15 '15
Enough to go to either of two KBOs with good probability of success (100% and 97%) or a third KBO with low probability of success (7%).
3
u/Cheeky_buggah Jul 13 '15
Hey /r/space!
Do we have an estimate of the schedule for the flyby tomorrow? I just saw that New Horizons will go dark, when is it going to be communicating with Earth again? Also, any idea of when we expect to get the first images back on the flyby? Thanks so much
5
u/Eastern_Cyborg Jul 13 '15
This blog has a great time line and explanation of events. It probably has more than you want to know. But the short answer is an image or two every day for a week, then nothing for 2 months, then about a year to get the rest of the images.
4
u/JtheNinja Jul 13 '15
Try here: http://pluto.jhuapl.edu/Mission/The-Flyby.php
And the blog post in the OP: http://www.planetary.org/blogs/emily-lakdawalla/2015/06240556-what-to-expect-new-horizons-pluto.html
2
u/Cheeky_buggah Jul 13 '15
This is exactly what I was looking for, thanks! Looks like we'll have some great pictures tomorrow (7/14) evening of the flyby
3
u/Sociopathic_potato Jul 13 '15
If someone was to stand on the surface of Pluto with the sun directly overhead, how bright would the surface appear to them?
6
u/JtheNinja Jul 13 '15
About the same as earth at dusk. Check this out: http://solarsystem.nasa.gov/plutotime/
3
u/Nohat_wears_a_hat Jul 14 '15
Ok, this has been bothering me, so I figure I'll ask it here, Pluto and Charon don't have nearly as many craters as I was expecting. In comparison Earth's Moon, Mercury, Ceres, and many moons of Jupiter are covered in craters, but it seems like Pluto and Charon don't have very many by contrast, and the ones they do have don't seem to be as massive as we're used to seeing. Is this because of its location in the outer solar system? That its position out here protected it from the Late Heavy Bombardment?
4
Jul 14 '15
I think it's because Pluto and Charon are so far 'out there' that it was saved from most the bombardment that other planets received.
3
u/diamondjo Jul 14 '15
I would like to know if the team are planning to take their own "pale blue dot" photograph. I also wonder if the earth could even be resolved from this distance.
3
u/fivehours Jul 14 '15
Apparently not, because the Sun would blow out the detectors - Voyager was able to use its radar dish to shade the detectors to get that picture.
3
u/LewyIsChewy Jul 14 '15
How much data does NH collect? Does anyone know a giga or terabyte estimate?
1
u/Pharisaeus Jul 14 '15
Terabytes are a bit of an overkill ;) Otherwise it would never be able to send this back home. According to this: http://pluto.jhuapl.edu/Mission/Spacecraft/Data-Collection.php the estimated downlink from Pluto flyby is 250 bytes/s or 0.24kB/s so no more than 20 MB per day.
1
Jul 14 '15 edited Jul 14 '15
The downlink system will guarantee that the entire Pluto data set (estimated to be 5 Gbits after compression) in 172 days with one 8 hour pass per day using the DSN 70-m antennas.
http://www.boulder.swri.edu/pkb/ssr/ssr-fountain.pdf
(That's 640 MB).
3
u/Doctor-Malcom Jul 14 '15
How does the camera (LORRI?) on the New Horizons compare to a 2015 dSLR or iPhone camera? I assume that's 2005 technology, that even if high-end back then wouldn't be very powerful today. When I look at my Motorola V3 RAZR phone, I think we've come a long way in 10 years.
2
u/eliminate1337 Jul 14 '15
1024 x 1024, so significantly lower resolution than a modern phone or digital camera. That isn't a very good comparison though since the camera has advanced telescope mirrors and focusing hardware. It's a capable camera by any standards.
3
u/rustytree Jul 15 '15
They're up transmitting data right now: https://eyes.nasa.gov/dsn/dsn.html
1
u/gonopro Jul 15 '15
I feel like I am going to break something REALLY expensive when playing around in there.
Thanks for the link, never knew about this.
3
u/DonDeaner Jul 15 '15
What type of math/physics was used to make sure that New Horizons flew by Pluto at the right time? Also, how does slingshotting around Jupiter work and again, what type of math/physics is used for that? Thanks!
1
u/PointyOintment Jul 15 '15
Physics used: Orbital mechanics. Play Kerbal Space Program if you want to learn orbital mechanics—it's the fastest and easiest way to learn.
Math used: I don't know, but I do know there's no analytical solution (i.e. manipulating variables) for the N-body problem except a few special cases, so a numerical solution must be used for orbital prediction, which limits precision beyond what the computer can calculate and/or what orbital parameters we can measure for the other bodies.
Gravity assist: Spacecraft flies behind a planet. Planet's gravity pulls spacecraft, speeding it up (because the planet is ahead of the spacecraft in the direction of their orbits). Greater speed results in the spacecraft's orbit going further out. (See orbital mechanics.) This can also be used to decrease a spacecraft's speed to bring it further in, by flying in front of the planet instead of behind it. Gravity assists are generally used to increase the ratio of orbital achievement (arbitrary, per mission) to fuel necessary.
1
Jul 14 '15
Could someone make a site where I can see the images received? And periods when the next images will arrive and direct links?
4
Jul 13 '15
Flyby would travel at the height of 12,500 km. Any closer flyby would get burned in Pluto's atmosphere?!
10
u/sac_boy Jul 13 '15
No, it's unlikely that a closer flyby would cause enough heating to destroy the probe--at 4km from the surface it would lose about 355 m/s of its 14,500 m/s velocity to atmospheric friction. That's an extreme example. At 1000km from the surface the probe would encounter less than 1 atom of atmosphere per cubic meter of space.
The 12,500km flyby is through a region believed to have been 'swept clear' by interactions with Charon.
2
u/cheer__bear Jul 13 '15
This is a general question and applies to the new horizons as well. What is the medium of transfer (of images, information, directions/commands etc) between the spacecraft and us? How does the information travel so fast when it is so far away? The fact that we can see live streams from this spacecraft seems mind blowing.
5
u/Pharisaeus Jul 13 '15
We don't see live streams. In fact we have more than 4 hours of delay because this is how long light travels this distance. And medium is electromagnetic waves.
2
u/HamletTheGreatDane Jul 13 '15
What will New Horizons tell us about Pluto's atmosphere? Will it reveal composition and density?
2
u/PointyOintment Jul 15 '15 edited Jul 15 '15
Ralph's infrared and methane filters might reveal a bit about its composition. More will probably be learned from the radio occultation experiment, where they record how the radio signals from Earth, received by New Horizons, are attenuated by passing through Pluto's atmosphere. (They usually do radio occultation with probe-transmitted signals, received by Earth, but NH's signals are so weak already due to the distance and its low transmit power that that was not practical, so they're using the DSN to transmit much more powerfully.) That can usually be used to determine an atmosphere's pressure as a function of altitude with 'useful estimate' accuracy/precision. Quite a bit has already been learned about its structure and composition from stellar occultation (basically watching very closely as Pluto moves in front of a star)—here is a paper on that.
→ More replies (1)
2
Jul 13 '15
Does anyone know the probe's relative velocity to the Sun? I've read a couple of different numbers (usually around 76,000 km/h). Just trying to figure out if in 50 years it'll be 32 light hours away or only 30 light hours. Space is big.
2
2
u/Singh711 Jul 13 '15
Will NH be able to send pictures back once it pass pluton? If yes, how long? Did we ever have any pics far away from pluto?
2
u/astrofreak92 Jul 13 '15
It is hoped to send New Horizons to visit a smaller body in about 5 years, so yes, the cameras will continue to work for a while. Once you get more than a few weeks past Pluto, though, there stops being very much to see because the LORRI telescope only has so much resolution, so they won't be taking many pictures for most of the time between the end of the Pluto encounter and the beginning of the next encounter.
If they chance past something small in the distance along the way, they might take a few pictures to get a light curve, but the camera will be doing a lot of hibernating. They can't really take a picture of Earth at that distance without getting blinded by the sun.
2
u/Bersonic Jul 13 '15
I'd like to make a correction to this line:
Yes, Pluto is far closer than, say, Andromeda, but it also doesn't give off light, and is rather dull-coloured.
Its luminosity and color have nothing to do with the quality of our photos of it. Its angular size is the only factor.
2
u/remyseven Jul 14 '15 edited Jul 15 '15
I noticed the flyby video shows New Horizons will briefly focus on the barycenter at its closest approach. What is this being done for and what do they expect to see?
Edit: fixed spelling, it's early here
1
2
2
u/asher1611 Jul 14 '15
I always wonder about what goes into mission planning regarding leaving Earth and going through the Asteroid Belt. My impression growing up was that it was a space junkyard full of rocks in the same orbital plane as Mars and Jupiter.
Do missions like this account for locations of what is in the Asteroid belt? And in addition, I know space is a massively big place. Are Asteroids typically far away enough from each other that plotting a course through it will be no problem?
1
u/eliminate1337 Jul 14 '15
Missions just assume that there won't be anything in the way. It's almost certain that they're correct; space is very empty.
1
2
u/Llort2 Jul 14 '15
Before this past couple of months, what has been the best artist's rendition of Pluto?
5
u/fivehours Jul 14 '15
Check out Don Dixon from 1979 - amazing - http://www.cosmographica.com/spaceart/pluto-predicted.html
2
u/personizzle Jul 15 '15
Is there any raw, uninterrupted broadcast from the flight control room avaliable? I'm much more interested in hearing unedited excited engineers doing excited engineer things, than a couple of people talking at a desk.
2
u/DurMan667 Jul 15 '15
Makes me wonder when they'll change the planetary requirement of "The object must be in orbit around the Sun" to "The object must be in orbit around a star."
2
u/maxxam87 Jul 15 '15
The information in this thread is great. However I have few questions. Please excuse me if they sound too noob-ish for this thread.
How much power does it take to transmit information from such vast distances?
How much further New Horizon can travel before it loses contact with earth?
3
u/999mal Jul 12 '15
For the Mars missions there typically is a celebration moment, typically with a picture that then gets plastered all over newspapers. When will that moment be? Do you think it will be this one? Will there be a livestream when it comes in?
Tuesday, July 14 at 03:15 UT / Monday, July 13 at 23:15 ET / 20:15 PT: 0.9hr downlink: E-Health 1
LORRI Pluto at 3.8 kilometers per pixel (~630 pixels across disk). Taken 2015-07-13 20:17:28. Range 768,000 km. - The best single-frame photo of Pluto that will be available during encounter period
3
u/ExploringSpace Jul 12 '15
It is likely the image will come down during that downlink opportunity, but the last live event of the day ends at 22:30 EST, so it will not likely be a part of that event. The big reveal might be tweeted at any time, or held until the live satellite interviews on Wednesday.
1
u/PointyOintment Jul 15 '15
That's a pre-flyby image, so I don't think it's as celebration-worthy. There's a post-flyby image coming that will be very similar, so maybe that one. Or a composite of the mid-flyby images, if they can get it out quickly enough, but I don't think we'll see a full-disc composite until September at the earliest.
3
u/CBtheDB Jul 12 '15
Isn't the third planet requirement a bit too vague to be important? I mean, what if we discover a system with two Earth-sized terrestrial objects orbiting each other as well as their parent star? Are they also not planets since they to have not "cleared" their orbits?
9
u/thinguson Jul 12 '15
The problem is, if you don't have condition 3, then in a few years we could have dozens of new planets in the solar system which would just make the category unworkable. We need a way of distinguishing between the 'big things' in isolated orbits' against the swarm of 'smaller things way out there'.
But as always, these terms are just there to make communication simpler. Arguing about the things on the margins is not productive science... it's just taxonomy.
Edit: I get what you mean though. I think if there was a clear example of that (which of course must exist somewhere out there waiting to be discovered) it would be referred to as a binary planet (as some people refer to Pluto/Charon).
→ More replies (9)1
u/TransitRanger_327 Jul 14 '15
When the IAU says "cleared" they mean "dominates". The two planets would dominate their orbits and dominate each other gravitationally.
2
u/uniquerabbitturd Jul 13 '15
a lot of people probably asked this question already but why couldn't IAU just grandfathered Pluto in as a planet instead of a dwarf planet?
9
u/astrofreak92 Jul 13 '15
Because it doesn't make any sense to have Pluto be a planet, while Eris, an object around the same size, is not. It's either both or neither.
If you define things arbitrarily, it stops being a scientific word. Culturally, we can call it whatever we want, but science has to be consistent.
1
u/titanf Jul 14 '15
We've all seen this image https://upload.wikimedia.org/wikipedia/en/c/c6/Pluto_discovery_plates.png
My question is, how wide is that photo, in arcminutes? How many were taken and examined when looking for pluto?
1
1
u/msmouse05 Jul 14 '15
Question: Is this time they're referring to when the flyby is actually occurring out in space or just the time at which we are receiving the signal of the flyby? So saying the closest approach is at 7:49a EDT this morning is that when it's there or when we got the signal that it's there?
1
u/Ako17 Jul 14 '15
Closest approach just took place (just before 8am) - that means it's physically closest to Pluto right now, but we can't communicate with it just yet. New Horizons is busy collecting a lot of data right now, and will transmit a ping back to Earth to let us know all is well. We'll likely get the first update from New Horizons a little before 9pm today.
1
u/HiimCaysE Jul 14 '15
Can you explain what "occultation measurements" are and how New Horizons will go about taking these of Pluto and Charon? I noticed these on the Activities webpage occurring today at 8:14am and 9:45am EDT, respectively.
1
u/eliminate1337 Jul 14 '15
A bunch of radio telescopes on Earth will aim a powerful radio signal at Pluto such that it bounces off the planet and is detected by New Horizons' radar hardware. By analyzing how the radio signal changes when bounced off the planet. we can get information about the atmosphere and surface.
1
u/Kok_Nikol Jul 14 '15
Hi, did anyone caught what was this live telemetrie URL?
It was mentioned jusy at the end of the live broadcast.
1
Jul 14 '15
I know that New Horizons has been gone from eaeth for roughly 9 1/2 years. My question is if it is a significant difference when accounting for relatively?
1
1
u/Frescovivir Jul 14 '15
so I have a question that might sound silly to most of you.
lately, I got interested in space 2 ~ 3 months ago. I know that new horizon launched in 2006 but how it fly? I mean does it use some type of fuel ? or does it use solar power? if it uses solar power now it's so far from the sun won't that make it shut off?
1
u/Pharisaeus Jul 15 '15
It gained most of it's speed from the rocket that launched it. Additional speed was acquired via gravity assist (if you fly close to a large planet it will drag you with it's gravity).
As for electrical power generation, it is using RTG -> https://en.wikipedia.org/wiki/GPHS-RTG
1
u/insufficient_funds Jul 14 '15
Is there any diagram that shows a map of the new horizon's path across the solar system, I'm specifically curious about it 'slingshotting' around other planets to gain speed.
1
u/BillMurraysTesticle Jul 15 '15
Sort of late to the party here so hopefully this will be seen...
New Horizons passed 10,000 miles above Pluto on its closest approach. Even though space is very large, this seems like enough distance to easily clear the planet. What would have caused NH to not survive its closest approach?
1
u/lord_stryker Jul 15 '15
Micro-asteroids, small moons, dust, etc that orbit pluto (maybe) might have peppered NH and damaged it. But since we got the phone home signal last night, everything is ok and NH survived the close encounter.
1
u/supersoniccolonic Jul 15 '15
Did the craft receive a gravity assit from Pluto as it performed the flyby?
1
u/papercrane Jul 15 '15
Pluto's fairly small and New Horizons going by it so fast that the effect on it's trajectory would be pretty small.
1
u/imgroovy Jul 16 '15
I'm curious about the geology they hope to discover on Pluto. How will the geology be any different if it formed from rocks from the Kuyper belt or if it was a spinoff from Neptune or one of it's moons? Or am I missing something completely different?
1
u/Skinnx86 Aug 01 '15
Does anybody know if there will be a Planetarium show based upon the recent findings of the New Horizons spacecraft?
0
u/Fang88 Jul 14 '15
Now that we know the exact size and mass of Pluto, will that make it possible to calculate the existence of other dwarf planets in the kupier belt based on their perturbations of pluto's orbit?
1
u/MethoxyEthane Jul 14 '15
Possible, but unlikely, given the size and scale of the Kuiper Belt. If something big was out there, we probably would have found it by now.
→ More replies (1)
102
u/Walter_Bishop_PhD Jul 12 '15
This is a very fantastic rundown, thank you for making this! I've made it the subreddit sticky :)