New Horizons Phones Home After Pluto Flyby -- Craft Healthy, Data Recorded

Tablizer was one of several readers to note that the New Horizons probe has completed its flyby of Pluto and radioed home to confirm that it went without incident. Mission Ops manager Alice Bowman said the spacecraft was healthy, full of data, and sharing telemetry. The images New Horizon collected haven't been downloaded yet, but NASA decided to tide us over by releasing this high-resolution view from the day before. It was taken when the probe was still 768,000 kilometers away with a resolution of 3.8km per pixel. (Closest approach was approximately 12,500km.) They also released an exaggerated-color image of Pluto and Charon which highlights the non-uniformity of both worlds.

Pictures from closest approach are not yet available. Expect another post late Wednesday or early Thursday with those images. The reason for this is that New Horizons can't take pictures and send them to us at the same time, so imaging activity is interspersed with downlinks to Earth to transmit data. Emily Lakdawalla has posted a downlink schedule. On Wednesday afternoon (ET), the probe will transmit three images of Pluto that were taken from 77,000km away, with a resolution of 0.4 km per pixel. They'll be the first three pieces of a mosaic of Pluto's surface, and the dwarf planet will fill all three frames. It will take a full 16 months for New Horizons to transmit all the data it collects. (Lakdawalla also added Pluto to a montage of the biggest non-planets in the solar system. New Horizon's measurements indicate Pluto is slightly larger than we thought. It's now considered the largest of the Kuiper Belt objects.)

Comments

It's larger than we thought, lets call it a planet

[youn]

lol, that surely won't wake up any old controversy :)

anyway, awesome to see images coming through

Re:It's larger than we thought, lets call it a pla

[Crashmarik]

Still say they should have named Charon, Goofy.

need for delay befor the images are released

[frovingslosh]

You can bet that, after NASA recently cut out of a live broadcast of the earth from space when 3 UFOs suddenly appeared in the video, that this data will be thoroughly picked through to make sure that there are no more unwelcome photobombs in these pictures.

Re:need for delay befor the images are released

[DeBaas]

yep, used to take NASA minutes to redact the alien bases out of the pics. But with all those conspiracy nuts nitpicking over a few artifacts in the pics they have to be much more thorough..

Re:It's larger than we thought, lets call it a pla

[lokedhs]

I'm sure people will now want to redefine planet as any object circling the sun with a radius of 0.185 km or greater (because obviously Eris at 0.1825 km can't possibly be a planet).

And, because this is the Internet, I'm being sarcastic.

NASA's amazing capabilities

[chipschap]

NASA's staff does amazing things and this is another one. Imagine what they could do with adequate funding, non-politicized leadership, and freedom from overwhelming bureaucracy. It's a huge credit to the staff that despite enormous obstacles they do a lot of great science.

Re:NASA's amazing capabilities

[dywolf]

Or just one day of funding to the illegal aliens with free stuff.

well obviously you have absolutely no clue how much we actually spend on that.

After 5:00 AM EDT

[mbone]

The first data download with pictures from the encounter (the "New York TImes" download) will start at 5:00 AM EDT Wednesday. Expect some in the morning, and a lot during the 3:00 PM EDT NASA Press Conference.

Re:It's larger than we thought, lets call it a pla

[lokedhs]

(Thank you frovingslosh for mentioning my mistake before I had time to comment myself). The dimensions I quoted are not km, but earth radii. That's what you get for copy/pasting from Wikipedia without even thinking (it should be obvious to anyone that Pluto is larger than a fraction of a km in diameter).

largest already

[arth1]

,

It's now considered the largest of the Kuiper Belt objects.

It already was considered that. Eris, the previous contender for largest dwarf planet, has not been considered a Kuiper Belt Object for a long time now, but a Scattered Disk Object.

Re:clean sweep

[Applehu Akbar]

The vehicles you refer to on Earth are autonomous, rather than being remotely piloted. Because of latency, all rovers on other planets have to be at least somewhat autonomous. Teleoperator control is only possible on the Moon, and barely.

Re:It's larger than we thought, lets call it a pla

[FatdogHaiku]

Well, there's no getting Pluto back to it's old status, now that they spotted those Kuiper Belt Loops...
http://xkcd.com/1551/

Control room as status reports came in

[Tablizer]

https://www.youtube.com/watch?...

There's no "redo" in this mission, and the probe could have encountered local particles where a sand-sized grain could have killed the probe during its dive past Pluto, perhaps part of a thin or ex-ring. There was a lot to be worried about during that "silent" main encounter.

It's kind of like sending your kid to college, but not hearing anything from or about him/her until her final report card comes in the mail.

Downlink

[Solandri]

Downlink speed is limited to 1 kbps (bits, not bytes). 2 kbps if they use a trick involving shutting down power to instruments to boost transmit power.

Reminds me of the early 1990s when JPEG images first started showing up. Full-color 640x480 GIF photo scans were a couple hundred kB and could take 10+ minutes to download over my 2400 baud modem. I was astounded that a 30-40 kB JPEG could look just as good to the eye. Course the JPEG took over half a minute to decode and display back then, but combined with download time it was still faster. (Yes computers and network speeds used to be that slow - it's why the early web made extensive use of thumbnail pics.)

Re:Downlink

[mbone]

Downlink speed is limited to 1 kbps (bits, not bytes). 2 kbps if they use a trick involving shutting down power to instruments to boost transmit power.

That's actually a dual polarization mode - this is the first spacecraft with a dual-polarization data transmit capability. (And, yes, it does require more power, and so won't be used until they are well past Pluto and can put things on standby.) Even with that, it will take 16 months to get all of the data back.

Re:Downlink

[Tablizer]

Back then I often used the browser's "switch graphics off" option for most sites since I didn't come to the Web for pics...well okay...maybe a tad of porn.

It's hard to switch graphics off in newer browsers. It's deeper in the menu tree or a plug-in.

I want that feature back for mobile devices, because they often either have 1990's speeds and/or have expensive bytes.

Re:Downlink

[stud9920]

What a waste of time. In these 10 years since launch, they could have precomputed every possible picture, hash them, and then the probe could have simply sent the hashes instead of the full size pictures.

Re:Downlink

[Big Hairy Ian]

Sorry I got baud of that

Re:Downlink

[bunratty]

But New Horizons was trying to avoid collisions, not create them!

Re:Downlink

[Lord Crc]

In these 10 years since launch, they could have precomputed every possible picture, hash them, and then the probe could have simply sent the hashes instead of the full size pictures.

Just for fun, let's see what it would take for them to pull this off. The LORRI image sensor is 1024x1024 pixels with 12 bits per pixel.

So the number of distinct images divided by the timespan available gives 2^(12*20) / (10 years) = about 5.6 * 10^63 hashes per second.

Let's say you had a CPU capable of computing one such image hash per nanosecond (very optimistic), you'd need 2^(12*20) / (10 years) / (1 nanosecond) = about 5.6 * 10^54 CPUs to pull this off.

For comparison that's an order of magnitude or so more than the number of nucleons in our earth.

If those CPUs consumed 50W of power computing these hashes (again very optimistic), the entire project would consume 2^(12*20) / (1 nanosecond) * (50 watt) = 8.8 * 10^64 joules.

For reference that's two orders of magnitude more than the total mass-energy (including dark matter) of the Virgo supercluster, the supercluster which contains our Milky Way galaxy.

Unless I messed up the calculations that is...

Why are we doing this?

[godrik]

I love cool probe taking pictures of distant planets (or whatever pluto is called these days). But why are we doing this? Just because we can? For the pleasure of exploring? Or is the exploration of pluto key in understanding some phenomena?

I was really excited about this

[jez9999]

I'd been waiting for this and following New Horizons so obviously it's great to see, but what slightly tainted the coverage for me was all the freaking USA flag-wavin'. Do you guys really always have to do that? Obama called it "American leadership". Look, I know it was launched and managed by NASA but it involved various non-US technology and experts, not to mention plenty of non-US interest (and non-interest from most US citizens who won't even have heard of New Horizons until yesterday).

I do think your nationalism ruins things a bit. At one point a NASA guy said it was "all about America" in a room full of US flags. Funny, I thought it was all about Pluto. Can't it just be a victory for human ingenuity and curiosity?

Re:I was really excited about this

[Anonymous Coward]

Most of the technology was american.
Most of the non-american technology was developed mostly with american technology.
Most to almost all of the cost was covered by US Taxpayers.

  I think that the US flag waving is fair. But I agree that's a victory for humanity. I guess I'd call it "American leadership" too..

Re:I was really excited about this

[jez9999]

In fact the core technology of the 2 main imaging devices, LORRI and RALPH, was British.

Re:I was really excited about this

[thrich81]

If you look at the history of the launch vehicle used for New Horizons, the Atlas V, there wasn't all that much German content in it. The "German rocket meme" applied strongly to the Saturn series of rockets developed almost in a linear progression from the V-2 by von Braun's group in Huntsville. But while von Braun was working for the Army and later NASA in Huntsville, the Air Force was developing the Atlas and Titan rockets independently of the Germans. And a few decades further back, Robert Goddard developed the technology of liquid fueled rockets before and independently of the Germans in the 1920's and 30's. Here is a statement by von Braun himself, 'He (von Braun) once recalled that "Goddard's experiments in liquid fuel saved us years of work, and enabled us to perfect the V-2 years before it would have been possible."' -- https://en.wikipedia.org/wiki/....

Re:It's larger than we thought, lets call it a pla

[bunratty]

They did name Charon, Doofus.

Re:It's larger than we thought, lets call it a pla

[Sique]

Actually, the five classical planets (which we call Mercury, Venus, Mars, Jupiter and Saturn) were known to all cultures we know of, thus we can call them "general knowledge", It has nothing to do with "European Aryan Übermensch". We can speculate that at least Uranus might have been discovered by other people than just Europeans, as the oldest known hint to its existence can be traced back to Hipparchos in 128 BC, but he didn't notice its planetary character. The discovery of Neptune with an apparent magnitude of 7.7 requires an optical instrument, as it is to dim to be discovered by a bare eye. Thus discovery of Neptune is restricted to cultures which were looking at the sky with optical instruments, which, as far as we know, leaves the Arabs and the Europeans.

Thus, you are wrong. Planets (at least the above mentioned five) were discovered by about any culture we know of, and rightly assumed to be different from stars.

Re:What comes after?

[Convector]

The spacecraft is powered by a radioisotope thermoelectic generator (RTG), but that's not a reactor. The power comes from heat produced by the decay of Plutonium, but there is no sustained nuclear chain reaction involved.

We need to teach these folks about English syntax

[jc42]

Lakdawalla also added Pluto to a montage of the biggest non-planets in the solar system.

Thus starts another round of the old "Is Pluto a real planet?" fiasco. ;-)

The pseudo-argument is really based on a poor understanding of basic English grammar. The word "dwarf" in the phrase "dwarf planet" is being used as an adjective modifying the noun "planet". A fellow at NASA (whose name I didn't catch) explained the fallacy of saying this means that Pluto isn't a real planet, by giving a few examples of the usage. Thus, we have several "dwarf apple trees" in our yard. Nobody who understand English would say that this means they're not real apple trees; they are real apple trees that bear real apples, but are much smaller (3-4m tall) than most (full-size) apple trees. Similarly, our sun is classified as a "dwarf star". This means that it's a real star that fuses H atoms and gives off light, but it's smaller than most of the stars you can see in the sky. This is a good thing, because a "full-size" star 140 million km from our planet would totally vaporize all our water, and would burn out in a few hundred million years, destroying our planet at the end of its life. If there are other intelligent critters on planets around other stars, those will also be multi-billion-years-old dwarf stars like ours (to within an order of magnitude). Most of the galaxy's stars are dwarf stars.

Readers can probably think of lots of other common uses of "dwarf" or "pygmy" to mean a small version of something. This isn't mysterious; it's standard English syntax. (We have a potted "dwarf jade plant". It's a real jade plant, but its parts only grow to about 1/3 the size of the equivalent "standard" jade plant. It's a very easy sort of bonsai to grow. But when we bring it inside for the winter, we have to protect it from our cockatiels, who find it tasty.)

Other astronomers have pointed out the major problem with the term "planet": It's far too inclusive. It includes object as varied as Mercury and Jupiter, so it's an almost useless classification term. The long-term sensible approach is to prepend various modifiers to say which of a list of classes a given planet is filed under. We have a few of them, like "gas giant", and the more recent "ice giant", of which our solar systems contains two each. The classification "dwarf" was added a few years ago for the tiny planets that can't hold an atmosphere. We still don't seem to have a standard classification for the 3 intermediate-size planets, Venus, Earth and Mars. We also haven't figure out good terminology for the similar objects (Titan, Triton, etc) that also have things like an atmosphere with weather, but which share an orbit with a planet in a larger class. Pluto is an interesting borderline case, because at the recent perihelion, it has had a very thin but significant atmosphere, which is now condensing out as the sun gets more distant.

In the long run, we really should have a reliable set of classes for the sort of astronomical object that's big enough to be (roughly) spherical but too small for fusion to happen in its core. We've found that there are lots more of them in our solar system than we thought, at least 6 with atmospheres denser with ours, and several with thinner atmospheres. Pretty soon, we'll be getting good data on similar objects orbiting other stars.

Calling all the round-but-not-stars objects "planet" is a useful term. But such a vague term really shouldn't ever be used without a prefix. Maybe the astronomical community should get a committee together to come up with a better list of planet classes than the current mess. And try to get the media and general public to use it correctly. ;-)

Or maybe they should just officially declare "planet" to be a non-technical term, with no precise astronomical definition. But then they'd have to come up with some new technical terms, so they probably won't do that.

In any case, saying a "dwarf planet" isn't a planet merely shows ignorance of basic English grammar. Some astronomers have pointed this out. We just need to get the word out to all the people who misunderstand it due to their poor command of the English language.