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Headshot of Emily Lakdawalla

New Horizons' best look at Pluto before close approach

Posted By Emily Lakdawalla

14-07-2015 8:12 CDT

Topics: trans-neptunian objects, New Horizons, pretty pictures, Pluto

Feast your eyes upon it!

New Horizons' best look at Pluto before close approach


New Horizons' best look at Pluto before close approach
This stunning image of the dwarf planet was captured from New Horizons at about on July 13, about 16 hours before the moment of closest approach. The spacecraft was 766,000 kilometers from the surface.

Here are my first impressions of this wonderful photo:

Wow, the surface is diverse. I see so many different kinds of terrain. The "heart" has broken up into two distinctly differet surfaces, a very smooth one in the west and a patchier one in the east. The dark stuff at the equator is very familiar; it looks just like Iapetus. But the bumpy terrain on the eastern edge is not familiar at all. I can't think of an analog for it.

I do see impact craters. To the left of the heart, in the dark area especially, there are several circular features that are pretty clearly impact craters. There are lots of other circular features visible, but I think it's less obvious that they are craters; it'll take a closer look to determine that. Topography will help. Tomorrow we will get another photo that is very similar to this one, but taken at a slightly different angle, which will give us 3D information to help see whether the circular features have crater shapes.

On the left side, I see some linear features, but they're too small for their nature to be really clear.

The pole is distinctly redder than the terrain around the pole. That's interesting. I wonder if it's the same phenomenon that's darkening Charon's pole.

On the left, I see some hints of the "mushroom terrain" that Voyager saw on Triton.

In sum, I see a little Iapetus, a little Triton, but a wholly unique world.

At a press briefing just now, I asked whether there was any evidence for atmospheric features -- clouds or hazes. Alan Stern said that they hadn't seen anything in the images yet, nor any plumes. But it's still early and there's a lot more data to come. When I tweeted this, I received a lot of responses from people who stretched the image and saw features around the edge. Those were likely JPEG compression artifacts -- believe me, if the haze were that obvious, the mission's scientists would have noticed it.

I am now crossing my fingers that the rest of the flyby goes well. We'll know in 12 hours....

UPDATE: I'll collect any notes that I find from science team members talking about this photo here as well.

09:39 EDT: I caught up with Will Grundy in the hallway. Will has done a huge amount of Earth-based observational work on Pluto. He told me that they specifically targeted this hemisphere to be the close-approach hemisphere because they knew it would contain the "contrastiest" part of the surface. From Earth-based spectroscopic data (not New Horizons data), we already know that the left side of the "heart" is made of carbon monoxide ice. He is surprised and pleased by the closeness of the match between the Earth-based maps of Pluto and what New Horizons is seeing.

10:00ish EDT: I caught up with Marc Buie, who headed the pre-New Horizons Pluto mapping efforts. He is pleased and surprised by how well the images match. Those efforts included two phases of Hubble mapping, and one set of maps computed from a bunch of "mutual event" observations, when Pluto and Charon eclipsed each other. He said the maps generated from the mutual event observations have a host of problems, so he is itching to get the New Horizons maps to subtract the major features out of his mutual event maps and look for evidence for temporal change.

See other posts from July 2015


Read more blog entries about: trans-neptunian objects, New Horizons, pretty pictures, Pluto


sepiae : 07/14/2015 08:33 CDT

That is truly amazing! I'm sitting here bobbing on a bar stool in exhilaration-anticipation limbo, having to remind myself that Fly-By Day doesn't mean it's pouring in... I thought we could have found it to be a more 'boring' looking object, instead it's utterly exciting (then I failed to come up with an object out there that looks boring). 'A little Iapetus, a hint of Triton...' :) You must be a wonderful cook. I was expecting mainly craters, instead this! Look at the spongy, marshmellowy terrain (the bumpy one)! Geo-history reads as scars and ulcers on the skin.

ThPlanetary: 07/14/2015 08:33 CDT

Glad you found NASA's 1MP PNG. I think it is unwritten policy NASA gets to release the biggest pictures first before JPL (and now APL) is allowed to. Memories of Saturn and Mars wow pictures. Great coverage! Congrats.

quayley: 07/14/2015 08:37 CDT

What a stunning picture! If that was the best image returned the whole mission would still be a triumph, can't wait for the next few days.

LocalFluff: 07/14/2015 09:07 CDT

This is the most fantastic image I've ever seen of any celestial object, except maybe for Earth and Hyperion. So many things are going on, or have happened, on Pluto. I'm not a geologist at all but the grand circular feature, the huge flat bright area and on and on. Wow!

Jerry Hilburn: 07/14/2015 09:41 CDT

In the millions of years it took us to evolve and in the last 100 or so, to learn how to leave our planet, Pluto has quietly and up until 1930, unknown to us, orbited the sun. At this moment we are the first of what will soon be many people on earth to view this incredible image of our success as a species. We may not be perfect but we did this! There is hope for us.

Mewo: 07/14/2015 09:42 CDT

Wow. "The other Red Planet" is amazing. I'm astonished at how smooth and uncratered Pluto is and I suspect that big beige plain of carbon monoxide ice must get re-surfaced every now and then judging by the lack of craters or black tarry tholins. That region in the east with the weird looking terrain seems at first glance to have been shaped by running liquid but I'm sure there must be another explanation. Unbelievably interesting.

Shah: 07/14/2015 09:43 CDT

An incredible achievement and effort. Was thoroughly impressed with the sheer work and planning that has been done to get where we are now. Probably you can highlight those behind-the-scene work as well.

ThPlanetary: 07/14/2015 09:57 CDT press release 15-149 is up with attached 'tn-p_lorri_fullframe_color.png' I believe this is the least modified release of this particular image we'll have in the near term. Pixels are indeed a bit different as the larger lossless file size indicates. Even if you're not intending to process the image, you won't want "...png-large.jpg" as a wallpaper. Whole lot of unnecessary re-compressing going on this morning: example:'s version of 15-149

Brian: 07/14/2015 10:10 CDT

The structures to the far east of the "heart" visually remind me of the basin and range structures of Nevada - although I would not conclude it has the same origin. What I do find interesting is how smooth the surface of the "heart" region is. It must be younger than much of the surrounding terrain. I look forward to learning what process might be responsible. I wonder how it compares to the age of Charon's terrain. The photos available so far make it look much more heavily cratered, but it will take a few of the higher-res photos to be sure.

rickray777: 07/14/2015 10:16 CDT

Good morning! Houston, we have craters! A little like those on Saturn's moon Enceladus, maybe? Nope, these are uniquely Plutonian! Looks like we're right on target; let's just hope, and pray...

Michael Hammerschlag: 07/14/2015 10:41 CDT

Amazing- the edge of our neighborhood. Disney would be proud. I have one contrarian question that I've always wondered: why Pluto, as opposed to Ukraine or Neptune- with 20-35 moons each and ~8 big ones, and the gas med giants... wouldn't they be alot more target rich destinations? So in my lifetime, we've jumped from earthbound monkeys to reaching near every planet!!

Messy: 07/14/2015 10:42 CDT

I was at the "Breakfast with Pluto" event at the American Museum of Natural history this morning and I hope you will forgive my feeling of Schadenfreude when I mention how Niel DeGrasse Tyson winced whenever someone in the Video feed called Pluto a planet, which was surprisingly often. I really look forward to the confirmation NH didn't blow up at nine this evening, and the photos during the next few days. The great data dump in September should be spectacular! As to new worlds, I have a some questions: As to that KBO, if they don't have the budget, are they just going to aim for it and take some pictures anyway? After all they mentioned they have enough plutonium to last until almost the World War II centennial, so it shouldn't be that expensive, right? Also, as to Juno, will on the outer end of it's orbits will there be any observations of the outer moons? Except for a few really bad navigation photos of Himilia, nobody's ever bothered to target them. Congradulations to everyone. This has been a fun week.

mikehoopes: 07/14/2015 10:51 CDT

I'm no geologist, but the eastern "heart" terrain reminds me of frost accumulation on the wall of a freezer (as opposed to the dendritic crystallization apparent in a freezer vent), which suggests that sublimated ices are preferentially re-accumulating in that area, perhaps with less interaction with solar energy and atmospheric wind than in other areas.

hendric: 07/14/2015 11:21 CDT

@Michael - The Voyagers had already done flybys of Neptune and Uranus. Pluto represents a whole new body-type, an outer planet in the last (giant) third of the solar system vs the modified moons or captured bodies at Neptune and Uranus. @Messy - Juno isn't in a position to take good pictures of any of the moons, and the camera included was a bone thrown to the E/PO groups - it doesn't have very high resolution, and is intended only for shots of Jupiter.

tedblank: 07/14/2015 12:05 CDT

Has there been any information released on the amount by which Pluto's gravity altered the probe's course during the flyby?

PeteD: 07/14/2015 12:26 CDT

Wow - fingers crossed for 00:30 UTC

Pete Jackson: 07/14/2015 03:17 CDT

I just thought of a good idea for a cartoon about waiting for the pictures of Pluto and Charon to come back: Scientist1 (looking at the first pictures): I afraid that, due to the long communication lag time, we may have programmed a little too much autonomy into New Horizons. Scientist2: What do you mean? Scientist1: All the pictures are coming back as selfies!

Ray Gedaly: 07/14/2015 03:23 CDT

Emily, a short time ago (~3 pm CDT) I observed on the DSN Now web page that Madrid was receiving a Carrier Wave signal downlink from New Horizons. This may have been the REX occultation experiment from Charon or Pluto reaching Earth. But doesn't this prove that New Horizons survived Closest Approach unscathed? Otherwise it couldn't have sent back this signal. Please ask the NH team. Thanks.

Ray Gedaly: 07/14/2015 03:44 CDT

Update: I'm wrong about the carrier wave signal possibly being associated with the occultation experiment. But if the DSN Now graphics are accurate, what was the carrier wave downlink from NH to Madrid DSS 63 at around 3 pm CDT? It showed a data uplink to NH as well.

dougforworldsexplr: 07/14/2015 05:43 CDT

I have an astronomy book of the solar system from the 1970s by Peter Ryan with artist Luked Pesek called Solar System that contains much good space art by Mr. Pesek. One of the paintings is what he and other people with some astronomical basis imagined the surface of Pluto to be like with the astronomical knowledge of the time. I hope some current space artists will soon produce and have publicized including perhaps with The Planetary Society realistic paintings, computer graphics or other space art taking into account more up to date information including from the so far very successful New Horizons Pluto spacecraft that the Planetary Society had a major role to help realize.

Arthur Hill: 07/14/2015 05:44 CDT

Beautiful image. Not sure if false color involved. That said, however, I do think I see evidence of erosion, so would be fascinating to speculate on weather processes at work here. Were I still science editor at The Houston Chronicle, it's a question I would ask at upcoming news conference.

Mark: 07/14/2015 05:50 CDT

The lighter area appears to be much younger than the rest of the surface due to the absence of craters.

Sidd: 07/14/2015 06:12 CDT

Love the heart. Absolutely amazing picture.

Bob Ware: 07/14/2015 06:55 CDT

Following the 'tongue' of ejecta, versus the usual blanket pattern, back into the basin center, is this an impact feature within the initial impact point or is it simply an isostatic rebound from the main impact or is it a caldera from a last gasp of internal heat? Looking at the size (by proportion) and the possible 'newness' of this feature, if it is a caldera, could this have been the source of the atmosphere thickening we saw a few years ago instead of a 'thawing out' of the atmosphere during the Summer months?

Bob Ware: 07/14/2015 06:59 CDT

@Arthur: This image is a color composite from LORRI & RALPH. RALPH is the lower resolution which was shot first, earlier that day, 07/13/2015.

Arthur Hill: 07/15/2015 01:06 CDT

Thanks Bob. Look forward to better images as we go forward. For tomorrow's presser, hope they will get into weather processes possibly at work. Also curious to know how the team works the trade off between acquiring data and transmitting back to Earth and what the ratio is: that is, can a day's worth of data from all instruments be transmitted in less time than it took to acquire it? Also, it was interesting to see NASA PAO leading cheers. Simply wasn't done in my day. Not that it wasn't deserved, but now the real work begins and real discoveries await.

Plutoresque: 07/20/2015 01:49 CDT

If we flip the photo upside down, we can see the features from a different angle, and the basin looks suddenly like the signature of a huge impact.

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