PLUTO WILL SEND EARTH A LOVE LETTER TOMORROW
TOMORROW, WHEN NEW Horizons makes its historic flyby of Pluto, it will be focusing in on just one face of the dwarf planet. In this latest photo captured by the space probe’s black-and-white LORRI camera, you can see that face—defined by a large, bright heart-shaped feature—beginning to rotate into view.
Only the top half of the heart is visible on the left side of this image, but come tomorrow, New Horizons will capture the valentine in full. (Viewers will have to wait up to a day and a half to actually see the image, since the probe will be too busy collecting data to send it back to Earth immediately.)
Rotating out of view, on the other hand, will be a number of other interesting geological details. The last good look New Horizons got of Pluto’s far side came in on Saturday. And this image is the best astronomers will get of the bullseye-shaped feature (to the right) that might be an impact crater. Without better images, the New Horizons team may never know for sure.
CHARON’S IMPACT CRATER EMERGES IN LATEST NEW HORIZONS SHOT
In the image NASA released of Charon yesterday, astronomers pointed out a collection of vaguely-defined features on the surface of Pluto’s biggest moon. Now, with this latest capture, the New Horizons team has confirmed that the big dent in the icy rock’s surface is in fact an impact crater, surrounded by a couple of deep canyons—one larger than Earth’s Grand Canyon.
Get ready for even more detailed images of Charon and its orbital buddy, Pluto, tomorrow morning when New Horizons makes its closest approach to the system. Geologists will be especially interested to take a closer look at the dark spot on the moon’s northern pole, and the rays of material you can see spraying out from the edges of the crater.
WATCH: HERE’S WHAT NEW HORIZONS’ PLUTO FLYBY WILL LOOK LIKE
Nobody is going to see New Horizons fly through the Pluto system. At least, not in real time. But thanks to the power of planetary physics you can watch the space probe pass by on your computer right now. NASA’s awesome visualization team has loaded the flight plan into their Eyes On The Solar System app.
The video above shows 8 hours of the flyby, speeding by at 10 minutes per second. The inset window shows what New Horizons’ suite of instruments see (and which instruments are currently active). And those images are updated as new data comes in.
“That is the best map of Pluto, and if they release another one tonight we’ll update it immediately,” says Doug Ellison, a NASA visualization producer. Like the rest of us, he’s really anticipating that new imagery. “It will be nice to put a map on Charon, it always sucks to have these gray potatoes in space.”
But if you’re really antsy for some real time communications, Ellison recommends you fire up DSN Now. This tool shows active communications from all NASA spacecraft. No need to burn your retinas waiting for New Horizons to perk up. The first communications post-flyby are scheduled to arrive at 9:07pm ET on July 14.
NASA FINALLY KNOWS PLUTO’S SIZE…KIND OF
At a press conference, New Horizons’ top dog Alan Stern just announced that his team has calculated Pluto’s most accurate diameter yet: about 736 miles from one end to the other, give or take 6 miles. You’d think this would be something NASA had nailed down by now, but it’s impossible to measure Pluto’s size without also knowing its distance from Earth.
That’s right: New Horizons is literally aiming for the unknown. The reason nobody knows Pluto’s exact location is because humans have only known about the planet for 85 years, which is about a third of the time it takes for Pluto to orbit the sun. The uncertainty is relatively small, but it affects all kinds of things.
Like the flight plan as New Horizons passes through the Pluto system. On Tuesday, New Horizons is programmed to rotate and focus its instruments on each of the dwarf planet’s moons in turn, and on the planet itself. If NASA’s estimate of Pluto’s distance is too far off, New Horizons will aim at blank spots in the sky.
Nobody here thinks there’s a huge possibility of missing the system completely, but some actually want the estimates to be a bit off. “Currently, as Charon rises from behind Pluto the camera is still looking at Pluto,” says Doug Ellison, a NASA visualization producer. On the Eyes On Solar System app, he showed me that if Pluto is a little bit closer than the scientists think, New Horizons will be perfectly placed to capture Charon rising behind it. “You hope for a little bit of uncertainty, because then you get that perfect Kodak moment,” he says.
This latest size estimate is slightly larger than what scientists had believed before, and it changes some other calculations. “It’s less dense, so that raises the question of the amount of ice in the interior,” says Stern. That’s because while Pluto’s size was up in the air, scientists have known the planet’s mass for a long time. A larger planet would mean less rock, more ice.
Ironically, scientists won’t get their best size and distance estimates until New Horizons passes through the system.
NEW HORIZONS’ FINEST MOMENT COULD BE ITS HOUR OF DESTRUCTION
Tomorrow, July 14 at 7:49:58 AM Eastern time, New Horizons will pass closest to Pluto. And it will gather its juiciest science during the hours surrounding the fly by.
Or everything could go horribly wrong.
“The most dangerous time for a collision is when you pass through the plane of Pluto’s equator and when you pass all the other satellites,” says Hal Weaver, the mission’s project scientist. But the danger won’t come from one of Pluto’s five (and counting) moons, it’ll be from bits of dust and rock caught in the planet’s gravity.
At 31,000 mph even a glancing blow from a mote of dust could send New Horizons into a tumble, interrupting its most scientifically productive moments. “But anything that sends it into a tumble could also destroy it,” says Chris Hersman, New Horizons’ system engineer. The most vulnerable spot is dead center, where the craft’s propellant is stored. In space, no one can hear you kabloom.
Neither will anyone on Earth. With all sensors trained on Pluto, New Horizons won’t phone home for 21 straight hours. How will radio silence affect the mood in mission control? Many scientists here admit to some amount of anxiety—and to soothing it withsuspicious rituals.
But rather than the sound of wind being sucked through a roomful of teeth, 7:50 AM will probably be filled with hoots, hollers, and hands slapping together. “I think it’s going to be pretty wild,” says Alan Stern, New Horizons principal investigator. Everything may have gone wrong, but that won’t stop the New Horizons team, friends, and family from celebrating 3 million miles and 9 and a half years of collision-free space travel.
CLIFFS AND CRATER-LIKE FEATURES APPEAR IN LATEST PLUTO SHOT
Let’s all take a second to appreciate the fact that this newest photo of Pluto was taken more than 1 million miles away from the icy dwarf planet. That’s how far away New Horizons will be tonight at 11:23 PM EST, on its way to an historic flyby on Tuesday morning.
You might be fooled into thinking Pluto and Charon look really similar, comparing this photo to the latest images of the big moon in the post below. But keep in mind that these images are uncolored, taken by New Horizons’ black-and-white LORRI camera. Once the team has the chance to add in color data from the Ralph camera, the differences between the planet and its moon become clear: Pluto is reddish-orange (not blue, like you might have thought), and Charon is more muted gray.
What’s really cool about these two is they are the only known planet/moon pair with a similar origin to Earth and its Moon. “This is the only other example of a giant impact planetary system,” says Alan Stern, New Horizons’ principal investigator. Of course the difference between the Earth system and the Pluto system being that the latter has many other moons in addition to Charon.
PLUTO’S BIGGEST MOON HAS A PERSONALITY OF ITS OWN
At about half the size of Pluto, it isn’t really fair that Charon has to take a back seat to the dwarf planet that it nominally orbits. The two bodies actually form a binary planet system, orbiting around a common center of mass. So it’s pretty awesome to see Pluto’s biggest moon (it has five that astronomers know of) come into its own as New Horizons approaches and delivers better and better photos of its surface.
This latest image begins to show some of the same geological features that astronomers have been oohing and aahing over in snapshots of Pluto. Specifically, geologists on the New Horizons team are interested in the 200-mile-wide dark region at the moon’s northern pole, and a group of chasms and craters on its lower half.
Unlike Pluto, which is covered with some kind of snow, Charon’s surface is bare—it should be easy to read. “If you’re a pure hard rock geologist, all those snows are just in the way of studying the geology,” says Alan Stern, New Horizons’ principal investigator. For reference, the cut all the way to the right in the image above is longer and miles deeper than the Grand Canyon. Take that, Pluto.
THE NEW HORIZONS TEAM HAS SOME WEIRD GOOD LUCK CHARMS
About an hour ago, Alice Bowman spoke to the Pluto Press Corps. She’s New Horizons’ Mission Operations Manager—basically the engineer in charge of making sure all the commands go up to New Horizons and come back down.
Bowman was on point when New Horizons took its 4th of July nap and freaked everyone out. The shut down was particularly harrowing because the ground team had just sent up the set of instructions that would guide the space probe’s instruments during its close encounter with Pluto. It was mission critical to get those back up.
“The best scenario to recover the spacecraft before the encounter was Tuesday, July 7th,” she says. She and her team—consummate engineers—accomplished the task with the efficiency and precision you’d expect. But, Bowman admits, they’re not above a little bit of superstition.
“We have a piece of wood that our PI (Alan Stern) gave us near the start of the mission,” she says. Yes, that wood is for knocking. The operations team also has a stuffed bear. “He’s been hibernating, but now he’s awake and has a party hat on,” Bowman says. New Horizons may be on a mission to bring home pictures of Pluto, but I won’t rest until I can capture some images of this little bear.
NASA DOESN’T CARE IF EVERYONE ELSE CALLS PLUTO A DWARF…
…They just call it interesting.
Hello from the Applied Physics Laboratory at Johns Hopkins University, mission control for the New Horizons mission, where Jim Green, NASA’s planetary science director just laid out the space agency’s take on Pluto’s status. In 2006, the International Astronomical Union reclassified the icy rock as a dwarf planet—a demotion in many astronomers’ eyes. But as Green says:
NASA’s position is quite simple: We do not care what we call this. It’s an object well worth observing.
In other words: When it comes to planetary science, size doesn’t matter.
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