Tuesday, July 14, 2015

Ex-Planet Watch: He-e-e-e-re's Pluto!


This photo is part of the binge of data New Horizons sent back yesterday before it stopped chattering with earth in order to focus on its up-close observation of Pluto. It was scheduled to reach its closest point to the "dwarf planet" at 7:50 this morning ET, and to check in with home at 8:53pm ET this evening.

BREAKING NEWS: New Horizons phones home!

Clearly this post was written before that fateful moment, at 8:53pm ET this evening, when the New Horizons spacecraft was scheduled to send a short data burst signaling the end of its communications blackout during its flyby of the ex-planet, now "dwarf planet" (as it's officially designated) Pluto. At 8:55pm ET, the Washington Post's Joel Achenbach reported:
NASA’s New Horizons spacecraft phoned home Tuesday night, reporting that it had made it to Pluto and beyond after crossing the solar system for 9.5 years. To the immense relief of the men and women who had built it and then flung it into deep space, the robotic probe sent a brief stream of data, received shortly before 9 p.m., confirming that it had survived the close pass of the dwarf planet.

“We have a healthy spacecraft. We’ve recorded data in the Pluto system. And we’re outbound from Pluto,” Alice Bowman, the mission operations manager, announced to her thrilled colleagues in the control room at the Johns Hopkins University Applied Physics Laboratory, the home of New Horizons. In a nearby auditorium, hundreds of people who had been watching the video feed stood and gave the team a standing ovation.

by Ken

By the time you read this, the New Horizons team headquartered at Johns Hopkins University's Applied Physics Laboratory in Laurel, Md., should know whether its space probe has survived its close encounter with the defrocked planet Pluto -- "even though," as Washington Post science writer Joel Achenbach wrote yesterday ("New Horizons is just hours away from Pluto after 9½-year journey"), "the speedy spacecraft [was] on track to pass about 7,750 miles from Pluto at 7:50 a.m. Eastern time Tuesday."

The spacecraft was programmed to stop gossiping with APL in anticipation of the flyby, in order to devote all its resources to the huge amount of work it was programmed to do while within range of Pluto, not to be heard from again until 8:53pm EST tonight, "when the New Horizons team hopes to receive a bulletin from the spacecraft saying that it has survived its close encounter with Pluto and is steadily making scientific observations."

Nevertheless, at the scheduled nearest-point moment this morning, as Joel reported early this afternoon, "Cheers fom hundreds of engineers, scientists and their families broke out" at APL.
“Pluto has now been explored!” exulted team leader Alan Stern a few minutes after a countdown clock reached zero at precisely two seconds before 7:50 a.m. That signaled the moment when New Horizons came closest to the surface of Pluto.
There was ample ground for nervousness during the long wait until tonight's scheduled "short data burst" check-in." As Joel noted yesterday:
This is not an encounter without risks. The Pluto system may have a fair amount of debris, and even a small rock could disable a spacecraft going upward of 31,000 mph. Stern said computer models show that the risk of a collision is 1 in 10,000.
Meanwhile the team already knows vastly more about Pluto than we have ever known, based on the pictures and data the spacecraft sent back during its approach to Pluto, before the communications blackout, which obviously already gave us a way closer look than we've ever had.

"People talk a lot about how surreal it is that we're really here," Joel quoted Alan Stern saying yesterday. "It feels like you've been walking on an escalator for almost a decade, and then you step upon a supersonic transport."

By "almost a decade," Stern meant the time it took New Horizons to make it to the vicinity of Pluto. Here's Joel again from yesterday:
This 9½-year journey to a tiny keyhole in space some 3 billion miles from Earth is the equivalent of a golfer on the East Coast hitting a ball across the continent and making a hole-in-one in Los Angeles, said the project manager, Glen Fountain.

“Pluto is perfectly spherical, like every respectable planet,” Stern said at a public lecture Monday at APL, in a dig at the astronomers who in 2006 demoted Pluto from “planet” to “dwarf planet” status. It has also turned out to be slightly larger than previously estimated.

“I didn’t know what to expect, because [Pluto] is a point of light when seen from Earth. It’s fascinating. It’s complex. You’ve got these dark regions and this bright, heart-shaped region,” said planetary scientist Cathy Olkin, another member of the New Horizons team. “I’m thrilled by how it looks.”
While cosmologically speaking New Horizons is still comfortably in our little corner of the universe -- still within our very own little solar system, albeit at the far edge -- practically speaking that's still a long, long away, and running a mission that distance away isn't like running, say, a moon mission. Here's Joel again from yesterday:
Because Pluto is about 3 billion miles from Earth, New Horizons can’t be joysticked from mission operations at APL. The nine-hour round-trip communication time means the spacecraft has to function autonomously. Olkin said the probe must make about 600 maneuvers over a nine-day period that started last Tuesday; that will enable 433 separate observations.

The designers of this $720 million mission have built in some redundancy, with multiple observations and slight wiggle room on the timing. New Horizons, launched in 2006, has star-trackers and other guidance capabilities to orient itself correctly and turn toward Earth to transmit data. What it doesn’t have, primarily for cost reasons, according to Fountain, is the kind of robust sensing and computing power to lock onto a target — say, one of Pluto’s moons — if that target is not precisely where it had been anticipated to be.

One inevitable feature of exploring the outer solar system is that the technology is relatively ancient by the time the spacecraft gets there.

“In some ways, these are technologies from the ’90s,” Fountain told reporters Sunday.


The New Horizons team at Johns Hopkins University's Applied Physics Laboratory watches incoming pictures sent back by the spacecraft yesterday. These folks are excited.

"Pluto is not a bland and featureless ball of ice, but rather a complex, variegated, mottled world with broad snowfields, structures that look like cliffs or fault lines, and a strikingly bright heart-shaped area that could be the eroded remnant of a giant impact crater."
-- Joel Achenbach, on washingtonpost.com at 6:30pm ET

Here's more from Joel this evening:
The newest photo of Pluto, obtained by New Horizons on Monday and made public Tuesday morning, thrilled the hundreds of people who showed up at APL for the encounter celebration. The most prominent feature is the “heart,” a bright, twin-lobed region with boundaries so sharp it appears to have been stamped onto the surface.

In fact that may not be far off, because one hypothesis that scientists said they’re discussing is that at least part of the heart — the left lobe — is the remnant of a huge impact long ago. It’s possible that region is a depression filled with nitrogen snow, said team member Casey Lisse.

Stern said there are indications of tectonic activity — perhaps even recently. Asked if the images show that there’s snow on Pluto, Stern said, “It sure looks that way.”

Project scientist Hal Weaver said there is a small bright spot that might be the tip of a mountain covered with snow. He said it looks “almost like a lighthouse.” Weaver cited a number of spots that bring to mind Almond Joy candy bars. “It looks like there are these great mounds — like the mounds with almonds on top,” Weaver said.

Linear features on the surface “could be scarps, or faults,” said New Horizons team member and planetary scientist Cathy Olkin.

But Stern cautioned that it’s too soon to reach any conclusions about things like mountains, faults, canyons or other kinds of dramatic topography. Scientists need to wait for stereoscopic imagery that remains stored on the spacecraft and will take time to download to Earth, he said.

That said, scientists uniformly rejoiced in the color variations and diversity of features. Pluto is not a simple and smooth snowball, which was one possibility before New Horizons got close enough to learn otherwise, NASA associate administrator for science John Grunsfeld noted in a news briefing. . . .

[Read on onsite. And stay tuned in the days, weeks, months, and years to come, as all the data sent back by New Horizons is sorted and understood. -- Ed.]
Do you get the feeling that these folks are, you know, excited? (What I love about Joel A as a science writer is his ability to enable us to both sort-of-feel and sort-of-understand what gets scientists excited. Thanks, Joel!)


In the above post I studiously avoided making the obvious point that to a lot of people the purpose of a mission like New Horizons' is incomprehensible, and probably scorned and derided. It seems to me fairly likely that the ranks of those people include the overwhelming majority of Movement Conservatives, and almost certainly most of the Republicans in that party's current majorities in both houses of Congress. To people whose brains have been ruthless purged of all curiosity about the universe and our place in it, the notion that an undertaking like this adds an important layer of understanding of the universe and our place in it is by definition preposterous.

In answer to my question, no, I can't imagine a project like this -- whose very purpose lies a decade in the future -- being authorized by the current Congress. As an exercise, look at the dozens of Republicans currently seeking the party's presidential nomination and ask if you can imagine any of them supporting such a thing. I can't. Once upon a not-so-long-ago time, one might have thought of Newt Gingrich possibly getting it. Which just goes to show anyone who thought the Newtster as intellectually hooliganish specimen of a politico as our system is capable of producing wasn't even close.

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