The die is cast. For better or for worse, the time is here.
Fifty years ago this Wednesday, the day after tomorrow, on July 15, 1965 we got our first close up pictures of one of our neighboring planets. We found out that Mars did not have a thick atmosphere, did not have lakes and oceans, did not have obvious plant or animal life. We also found out that it was a unique and amazing place and we’ve spent the last forty years orbiting, landing, and roving all over it.
Tomorrow, on July 14, 2015, we will get our first close up pictures of the last big chunk of our solar system, Pluto. If the last fifty years in planetary science have taught us anything, it’s to expect the unexpected.
Someone pointed out that we’ve gone from the first powered flight in 1903 to flying by every one of the planets in only 112 years. That’s not bad. I wonder how many of those planets, asteroids, and moons will have humans living on them 112 years from now. (Make a note: Check back on this on July 14, 2137.)
How big of a feat is this? It’s the fastest spacecraft we’ve ever launched. It will pass Pluto at nearly 31,000 miles an hour. It’s the furthest out we’ve ever examined another planet. It’s the longest we’ve ever had to wait until we got to our final destination. And if the New Horizons team is granted the funding and go-ahead for an extended mission, in five to ten years they’ll pass by another Kuiper Belt object and re-write all of those records as well.
How accurate is the targeting and navigation on the flight to Pluto? It’s the equivalent of hitting a golf ball in New York City and making a hole-in-one on the fly (no bounces!) in Los Angeles. Nearly four billion miles from Earth, nine years of spaceflight, slingshotting around Jupiter along the way to pick up speed, and they’re hitting a box that’s 60 by 90 miles, located 7,750 miles from the surface of Pluto.
Image: NASA / JHUAPL / SwRI
Why do they have to hit that box accurately? Couldn’t they just get “close enough?” Well, no. First of all, Pluto and New Horizons are 4:26 light-hours away from Earth. When something happens at Pluto, it takes 4.5 hours for us to find out about it, and 4.5 hours for our answer or instruction to get back to Pluto. When things are happening every couple of minutes, a nine-hour delay just won’t cut it. So New Horizons is pre-programmed to make all of its science readings and take all of its pictures. This involves a whole series of swings back and forth and up and down in order to point different instruments at different places in the Pluto system. If we’re off course and Pluto and its moons aren’t where we expect them to be, then we’ll be taking pictures of nothing but deep space.
(For those of you who weren’t here yesterday, “JHUAPL” is the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and “SwRI” is the Southwest Research Institute in Boulder, Colorado. If you don’t know what “NASA” is, I have no clue why you’re reading this site.)
Diagram: NASA / JHUAPL / SwRI
Secondly, after closest approach to Pluto, New Horizons is targeted to fly through the shadow of Pluto and the shadow of Charon. Looking back as the sun sets and rises past the edge of the planet (or moon) and through its atmosphere (if any) will tell us a great deal about the composition, density, and height of the atmosphere. In addition, as New Horizons goes behind Pluto and Charon it will also lose sight of Earth. New Horizons might not be broadcasting to Earth, but it can listen. We will be blasting out a radio signal and the way that signal varies, falls, disappears, and is regained will also tell us a great deal. But in order to be in those two right places at those two right times, New Horizons needs to hit that 60 miles by 90 miles box.
How good will our pictures get? Before New Horizons, these were the best pictures ever taken of Pluto, using the Hubble Space Telescope.
Photos: NASA / ESA / M Buie, SwRI
What about Pluto’s moons?
Photos: NASA / ESA / JHUAPL / SwRI
The New Horizons team spent a lot of time trying to find any new moons around Pluto or any signs of debris or dust near the planet. Moving at 31,000 miles an hours, it wouldn’t take much to trash the spacecraft. In the end, nothing was found, even by New Horizons as it got closer, so the odds of an accident are at 1 in 10,000.
When trying to get detailed images of Pluto, Hubble is a really big telescope that’s a really, really long way away. New Horizons is a much smaller telescope that’s been getting closer like a bat out of hell. (Spoiler alert: New Horizons wins!)
Photos: NASA / JHUAPL / SwRI
By July 2014 New Horizons could clearly see Pluto and Charon, although just as a small dot and a big dot. But it could see them orbiting each other, as this twelve-image animation taken over four days shows.
Photo: NASA / JHUAPL / SwRI
Once we got into April 2015, the pictures taken by New Horizons were as good or better than the ones taken by Hubble. Color data indicated that the educated guesses were correct. Pluto has a reddish tinge to it, while Charon is more grey and white.
Photos: NASA / JHUAPL / SwRI
By mid-May 2015 we were starting to see more surface features on Pluto than we ever could have using Hubble. These images, taken over the course of four days, show one full rotation of Pluto.
Photo: NASA / JHUAPL / SwRI
Last week, on July 8th, we got this color image, showing the “heart” formation on the right near the equator. With luck we’ll get to see it more closely during the pass near closest approach.
Photo: NASA / JHUAPL / SwRI
Three days ago, on July 10th, we started to see much higher detail on Pluto, including all of those hexagonal-shaped areas and that dark belt along an area near the equator. The equatorial dark area actually had been predicted, as a result of seasonal heating melting ices, which are then transported to the poles by the atmosphere where they freeze out again. The dark belt is the “sludge” left behind when the equatorial ices melt, primarily tholins and other hydrocarbons. As we get closer, the other instruments on New Horizons should give us much more data on the composition of the surface ices and the atmosphere.
Photo: NASA / JHUAPL / SwRI
Yesterday, on July 12th, we got this final picture of this side of Pluto. All of the close encounter pictures will be of the other side, and by the time this side rotates back into the view of New Horizons the spacecraft will be on the night side and we don’t expect to be able to see anything. Out here, when we say “dark,” we really mean “dark!”
Which brings me back to another point that was mentioned about seven weeks ago. While the dark side of Pluto and Charon and the other moons are extremely dark, i.e. pretty much nothing but starlight unless one of the other moons happens to be over the horizon and casting some extremely dim moonlight, daytime on Pluto still isn’t all that bad as far as the seeing would go.
There’s another free NASA website you can visit to see what your local “Pluto time” is. This is the time at your location when the amount of light outside is approximately the same level as you would see at high noon on Pluto.
It’s much more light than I had expected. For me tonight, it was at 20:12, which was nineteen minutes after sunset. (Click on the image to enlarge it.)
You could read a newspaper by this much light. Most of Los Angeles’ drivers don’t bother to have their headlights turned on in this much light. (Seriously!) On Pluto, if there were clouds in the sky they would be much thinner, as would the atmosphere, and so cold you couldn’t even begin to get warm with all of the Starbucks coffee ever brewed. It would be about 385°F colder, and that’s at noon. At night it would really get cold and dark.
(That’s when the ice weasels roam, but that’s a different story.)
Pluto has five moons that we know of so far. Hydra, Nix, Styx, and Kerberos are all small, no more than 40 miles in diameter at current estimates. We hope to get much better estimates on their sizes and shapes (and maybe a couple of distant pictures) when all of the New Horizons data has been downlinked in a year or so. Nix and Hydra are thought to be elongated, somewhat cigar-shaped, and a recent analysis theorized that their rotations might be chaotic. In other words, instead of the usual “sunrise in the east, sunset in the west, here’s the equator, here are the poles” routine, they might tumble, split, flop, roll, and rotate at random as they’re pulled around by the gravity of Pluto and Charon. There’s a pretty cool animation here courtesy of NASA / ESA / M. Showalter (SETI Institute) / G. Bacon (STScI).
That’s four of the five moons. The other one is in a class all of its own. Charon is so big compared to Pluto that it doesn’t actually orbit Pluto itself. Pluto and Charon orbit each other around a balance point (barycenter) which is actually out in space approximately 960 km between the two bodies. (The Earth and Moon also actually rotate around a barycenter, but in their case the barycenter is not out in space, but 4,671 km from the Earth’s center and 1,707 km below the Earth’s surface.)
In addition, Charon and Pluto are tidally locked, always showing the same face to each other. If you lived on the “far side” of Pluto, you wouldn’t ever see Charon, and if you lived on the “far side” of Charon, you wouldn’t ever see Pluto. Even more cool, if you lived on Pluto at the “sub-earth point” directly under Charon, it would look to just hang there in the sky, not moving, not rotating. For the ultimate in cool, sit on Charon at the sub-earth point directly under Pluto. It would be HUGE compared to the Moon in Earth’s sky, but again, it would just hang there forever, not spinning, not moving, at least, from your point of view.
These two sub-earth points also make a very handy place to define as the the 0° prime meridian for cartography purposes on both Pluto and Charon.
Next crisis – how in hell do you pronounce “Charon?” Is it “sharon,” or “karen,” or “ki-ron,” or “kay-ron,” or something else.
Yes. It is. No one really has defined it and there is no agreed upon usage. For example, in this morning’s NASA-TV press conference, Alan Stern, the project principal investigator, used “sharon.” One of the other panelists use three different pronunciations, mostly “sharon” and “karen” with an occasional “kay-ron” thrown in for entertainment and chaos purposes.
I go with “sharon,” but I don’t know that it’s anything I’m real passionate about.
Is Pluto a planet? A “dwarf planet”? A “double planet”? A “plutoid”? (Actually no one uses “plutoid,” including the person who proposed it.)
Again, as in the sharon/karen/kiron/kayron issue, I don’t care. According to the IAU, it’s not. I grew up thinking it was, but most folks don’t know that in the late 1800’s and early 1900’s it was taught that Vesta and Ceres were planets as well. Then we found out how small they were and that they were just part of a much bigger belt of asteroids, and they got “demoted.” Or “reclassified to correct the original mistake.” Po-TAY-to, Po-TAA-to!
If I had a vote, I would come down on the side of “planet.” The argument against that is that we’ve now discovered several Kuiper Belt objects way, way out there that are (probably? possibly?) bigger than Pluto – if we call Pluto a planet, do we call Eris, Haumea, Makemake “planets” also? What about Ceres and Vesta? Do they get “re-promoted?”
It’s a stupid argument. How about we go send landers, orbiters, and rovers to every one of them, regardless of what they’re called. Let’s do it simply because they’re all really cool and unique “chunks” of the universe that are close enough for us to study in our lifetimes?
In the future, we may call this the “Willett-‘chunk’ Theory.” (I like it!)
- It’s been a fantastic time to be alive though this First Golden Age of Space Exploration.
- There are a ton of resources for you to follow along as we have our “last first time” of the First Golden Age – and head off into the Kuiper Belt for the beginning of the Second, we hope.
- New Horizons is now closer to Pluto than the Moon is to the Earth.
- New Horizons is busier than a long-tailed cat in a room full of rocking chairs as it twists and turns its way through a long sequence of pre-programmed actions to take data and pictures as it tears past Pluto and Charon tonight.
- New Horizons did take a few minutes three hours ago (about 23:00 EDT, 20:00 PDT) to send down a quick, highly-compressed image (so it will look jaggy and rough) and a load of engineering data that will give a quick snapshot of how it’s doing.
- We won’t be watching live as any of the events a Pluto happen. Almost four and a half hours (4:26 to be exact) in one-way light travel time, nine hours round-trip – New Horizons will live or die on her own.
- At 05:30 EDT (02:30 PDT) NASA-TV will be on the air for a show about New Horizons from JHUAPL. Expect a whole slew of features we’ve seen before, maybe some new ones, and interviews with lots of nervous and very, very sleep-deprived scientists and engineers. (Some of them may have black coffee or Red Bull IV’s going.)
- At 07:49:57 EDT (04:49:57 PDT), New Horizons will be at its closest point to Pluto.
- At 07:30 EDT (04:30 PDT) NASA-TV will air a live “mission celebration.” We still will not have heard a single thing back from New Horizons. (The speed of light is a bitch!)
- At 08:00 EDT (05:00 PDT) there will be a New Horizons news briefing on NASA-TV. Other networks may carry it as well. There still will not have been any word back from New Horizons. They will probably release that grainy, compressed photo that got downlinked tonight with the engineering data.
- At 09:00 EDT (06:00 PDT) NASA-TV will be carrying more interviews with Charlie Bolden and New Horizons engineers and scientists. Will any of them have any news or any new word from New Horizons? (Hint: Nope!)
- Tomorrow evening, NASA-TV will be back to watch as the first radio contact since the Pluto encounter is received. Nominally this is expected about 20:53 EDT (give or take five or ten agonizing minutes as data is captured by the Deep Space Network and flung around the globe back to Maryland), but the current NASA-TV schedule says they have their news conference at 21:30. Stay loose, stay connected, and let’s hope that someone’s live when that first signal and first new picture come back just before 21:00 EDT (18:00 PDT).
You’ll know what the results are by the reactions in the room. If everyone starts screaming, hugging, crying, laughing, and generally losing their shit, then you know that New Horizons is fine and data is coming down. If the silence goes on and on and on and people start gulping antacids and anti-depressants like M&Ms, well…
Me, I’ll be ready with the Vuvuzela Of Rejoicing, ready to play it loud enough to be heard all the way in Maryland.
Image: NASA / JPL Eyes On The Solar System
We’re 187,344 miles out, at 30,821 MPH, 06:5:48 from closest approach, and about 18:55 from the next word from New Horizons.
Buckle up. It’s time to science!