New Horizons reveals much, raises questions about Pluto

I overheard a little academic snark after a recent University of Washington astronomy colloquium. “It must be nice to be a planetary scientist,” said one attendee. “The answer to everything is, ‘I don’t know.’”

Will Grundy.
Photo: Lowell Observatory.

The topic of the day was Pluto, and the speaker was astronomer Will Grundy of Lowell Observatory. Grundy is a co-investigator for the New Horizons mission that flew past Pluto last July and will be beaming data back to Earth through the end of this year. He heads up the mission’s surface composition science theme team.

To be sure, Grundy’s talk was peppered with words like probably, puzzle, conjecture, speculation, and, yes, “We don’t know.” To be fair, we have learned quite a lot from a spectacular collection of snapshots beamed back to Earth from a dwarf planet three billion miles away. UW astronomy professor Don Brownlee talked about the scientific achievement, and the advances of the last 50 years, in his introduction of Grundy.

“Mariner 4 went to Mars and took 22 exciting pictures which we would now think were absolute dirt because they were 200 by 200 pixels and had very poor signal-to-noise ratio,” Brownlee said. “We’ve had this fantastic half-century of discovery of things where objects in the solar system went from dots to actual worlds. The last first-time is Pluto.”

One thing that we know fairly definitively is the variety of materials that are on Pluto’s surface. Grundy, who is a spectroscoper, showed many of the colorful images that reveal which compounds are there.

“The outer solar system would be a really colorful place if our eyes could just see a little farther out into the infrared,” Grundy noted, “but I guess it wasn’t advantageous to us running around on the African savannah to be able to distinguish methane ice from nitrogen ice.”

“The outer solar system would be a really colorful place
if our eyes could just see a little farther out into the
infrared,” says New Horizons scientist Will Grundy.
Mission scientists made this false color image of Pluto
using a technique called principal component analysis
to highlight the many subtle color differences between
Pluto’s distinct regions. Image: NASA/JHUAPL/SwRI.

Many other images showed the fascinating and varied terrain of Pluto, and this is where a lot of the we-don’t-knows come in. There are features that look for all the world like drainage canals, but it’s way too cold on Pluto for liquids. Perhaps the features were caused by glaciers, or some material we don’t know about. Other areas show what look like sand dunes with ripples on them, but Pluto’s atmosphere is too thin to blow sand around. Perhaps there was a thicker ancient atmosphere. Each photo revealed amazing detail and features, and many may well remain mysteries until more data can be collected.

“All of these different things are going on on different time scales,” Grundy said. “Sorting out the processes that we’re seeing here is going to be a fun challenge.”

The images are truly remarkable, though Grundy suggested they’re even better in higher resolution than he could display on the lecture-room screen. He suggested delving into the New Horizons image archive for some good viewing.

Pluto may seem insignificant to some, especially in light of its reclassification to dwarf planet, but Grundy said it’s well worth it to explore the “cold fringes of the solar system.”

“These things are really faint, really far away, really hard to get to, not huge,” he said. “Arguably they are the debris that’s left over from the formation of the giant planets, and they preserve a lot of clues about the planet-formation process specific to our solar system and perhaps general solar systems more broadly.”

“From my point of view, I’m just interested in exploration, just seeing what the objects out there are like.” Grundy continued. “If you like geology, or real estate, most of the solar system’s solid surface is out there.”

As New Horizons continues to beam back data it collected during last summer’s fly-by, it also is zipping toward another Kuiper Belt object, 2014 MU₆₉, at which it will arrive on New Year’s Day 2019.

There’s another chance to catch Grundy’s presentation about Pluto coming up this weekend. He is scheduled to give a talk titled “Pluto and Charon Up-close” at 2:15 p.m. Sunday, May 22 at the PACCAR IMAX Theater at the Pacific Science Center. It’s part of the center’s on-going observance of AstronoMay.

St. Louis on the edge for 2017 total solar eclipse

From Seattle we’ll have to drive about 200 miles south to get to the edge of the path of totality for the total solar eclipse that will cross the United States on August 21, 2017. The north edge of the path will cross I-5 near Aurora, Oregon. In St. Louis, the edge of the path cuts right through town. It sounds convenient, but Don Ficken, who chairs the St. Louis Eclipse 2017 Task Force, said there are disadvantages.

“St. Louis is, in many ways, blessed by the fact that we have an eclipse coming through at least the southern part of the city,” Ficken said. “In other ways it’s a challenge. It’s not like Nashville where it’s going through the core; it’s basically just hitting the edge of the city.”

The northern edge of the path of totality almost cuts St. Louis in half, with the south and west sides of the city being in, while the north and east sides are not. Many big attractions in St. Louis, such as the Gateway Arch, Forest Park, Busch Stadium, the Zoo, and the St. Louis Science Center all lie outside the path of totality, while those inside the path will experience a shorter eclipse of a minute or less.

“When we talk with the main core of the city, it’s kind of hard for them to get real excited when they’re really on the edge of the eclipse,” Ficken said.

Thus, for the St. Louis area, the focus of eclipse planning has been on the more rural areas that are deeper into the path of totality of the eclipse. They began their work in 2014 but really got going in earnest at a workshop last fall.

“We decided up front that we were planning to inspire—in other words get people excited about it, educate and tell them about what’s going on, and then of course connect them to the resources, but we do not want to plan any events,” Ficken said. “We’re simply trying to raise awareness and do everything we can to get the region ready.”

The task force created teams that work with the many different counties and municipalities within the eclipse path. The St. Louis Astronomical Society, of which Ficken is a member, has been doing its part. Last weekend the club had a booth, for the first time, at the Spirit of St. Louis Air Show. They’re doing other outreach in an effort to reach at least 25,000 people with information about the eclipse. Part of the outreach is linked to their library telescope program, which has made 88 scopes available for checkout from area public libraries.

“We are doing programs, working with the public in the libraries right within their communities,” Ficken said. “Not only do we explain how the telescope works, but we talk about the solar eclipse coming up.”

Their best prop is a display map of the eclipse path, which Ficken said really grabs people’s attention and interest. They get to see what is coming their way.

“We’re going to be doing a ton of outreach to raise the visibility, which will then create, we think, more pressure to actually plan actual events,” he said. The work is beginning to pay off.

Don Ficken
Photo: LinkedIn

“Particularly the rural areas are so juiced on this thing; they’re excited, I mean really excited,” Ficken said. “This is like the biggest thing that’s probably ever going to happen to some of them and they’re on the map. Particularly little towns like Festus and Perry County; Perryville is just going bonkers down there with their planning. It’s like the biggest event forever for these guys down there.”

St. Louis is a great choice as an eclipse viewing destination, according to Ficken. As a major metropolitan area, there’s a lot to do there. Come eclipse Monday, it’s an easy drive to go south or west to get deeper into the path of totality, with center-line towns just 30 to 40 minutes away.

“You’ve got plenty of time to get where you want to, get all settled in, and just have some fun,” Ficken noted. “For those who want to just make an easy trip, have a great weekend, have some fun, add a third day on to make it a three-day weekend, we’re really perfectly suited for that.”

Many towns and businesses within the eclipse path have committed to having events for the eclipse, though a significant number of them haven’t settled on the details yet. As they’re confirmed, they’ll be posted on the St. Louis Eclipse 2017 website. Ficken expects the interest to snowball.

“We’re excited, we have lots of great stuff going on, but I expect a lot more to happen as we get into fall and the media starts picking up on this,” Ficken said. “It will be crazy.”

The universe is big, even in small spaces

The universe is pretty vast even in confined spaces. That was the lesson given on opposite ends of the size scale at the most recent Astronomy on Tap Seattle event hosted at Hilliard’s Beer Taproom by University of Washington graduate students in astronomy.

Ethan Kruse

Grad student Ethan Kruse was all set to give a talk that concluded we would never even get out of our solar system because it is way too big. Then a few weeks before the talk Stephen Hawking and friends announced their plan for getting all the way to neighboring star Alpha Centauri in 20 years through a project called Breakthrough Starshot.

“If I’m disagreeing with Stephen Hawking,” Kruse recalled thinking, “I should probably stop for a minute and reevaluate my thesis.”

Kruse remained on point about the mind-boggling scale of the universe. He said that if our Sun was the size of a basketball sitting on the stage of Hilliard’s, Earth would be the size of a sesame seed in the back of the room, 84 feet away, and the orbiting Moon would be the size of a grain of salt. At this scale Jupiter would be a golf ball on the Ballard Bridge and Pluto would be a grain of salt about a kilometer away—about the distance to Bad Jimmy’s Brewing Company, which served as the venue for Astronomy on Tap Seattle for its first year. Alpha Centauri, in this set-up, is some 4,400 miles away—in London or Tokyo.

Kruse pointed out that the fastest spacecraft we have built so far, New Horizons, took a decade to get to Pluto.

“We went from Hilliard’s to Bad Jimmy’s in ten years,” he observed. “Don’t worry guys, we’re going to go to London in 20 years!”

The idea behind Starshot is that a super-light craft with a light sail could be accelerated by lasers to up to 20 percent of the speed of light. Kruse outlined a litany of technological challenges with the concept, including the ability to generate sufficient laser power, creating an adequately reflective material for the sails, being able to accurately aim the lasers at great distances, and shielding the craft from possible collisions with space debris. Still, he concluded, the idea is worth exploring, especially since the same technology could be used to explore the solar system more quickly.

“This is honestly the most realistic thing that anyone has proposed so far for getting to any other star system,” Kruse said.

It will, however, take a great deal of research and development.

“Don’t necessarily count on this before you die,” Kruse concluded. “Space is big.”

Jessica Werk

Professor Jessica Werk, one of the newest hires onto the astronomy faculty at the University of Washington, also used sports equipment to illustrate her talk, “The History of You: The Rather Tumultuous Past of the Atoms in Your Body.” Werk pointed out that atoms are mostly empty space. If the nucleus of an atom were the size of a baseball, the nearest electrons would be a football field away.

After the Big Bang the universe was mostly light atoms: hydrogen and helium and a few others. Where did the carbon and calcium and other heavier stuff we’re made of come from?

“All evidence suggests that these atoms were fused in the cores of very, very massive stars twelve-and-a-half billion years ago,” Werk said. “Since then they have been on an absolutely crazy, long, sometimes violent journey to end up in your body 93 million miles from the Sun on this speck named Earth.”

Those atoms took a somewhat circuitous route to get here.

“Sixty percent of the atoms in your body we at one point outside of the galaxy in the circumgalactic or intergalactic medium,” Werk said. We don’t really know how they got here, but the best theory is that the atoms tend to cool off, and the gas rains back down on the galaxy, collapsing in star formation or becoming part of the debris disk out of which planets form.

There’s some mind-bending scale at the atomic level, too. Werk pointed out that there are 10²³ atoms in a breath of air.

“Each breath-full of air contains more atoms than the number of breath-fulls of air in the entire Earth’s atmosphere,” she said. “What that means is that it is very likely that the last breath of air you just took contained at least one oxygen atom from the first breath of air that you ever took as a human being on planet Earth.”

That reminds us of a recent post by Ethan Siegel on the blog Starts With a Bang, in which he concluded that we all probably share atoms that were once part of King Tut or any other historical figure you might name.

“The matter that makes up your physical body is part of a huge universe that is continually evolving and recycling the material in it into new forms,” Werk concluded.

Catching the Mercury transit from Seattle

The weather gods smiled on West Seattle Monday and provided relatively clear skies that allowed us to catch much of the first transit of Mercury across the disk of the Sun in ten years. The event served as a reminder of how hyper-local the weather can be, as many other locations around the area did not fare so well.

After about 8:30 a.m. May 9 

the clouds parted and we had 

excellent viewing of the transit of 

Mercury. Spencer (left) and Ryan 

take a peek through Spencer’s 

homemade Dobsonian. 

Photo: Greg Scheiderer.

We thought we may have jinxed the weather when we wrote on Sunday in our weekly calendar post that, “(I)t’s pretty unlikely that we’ll see the transit constantly from sun-up to finish, but also looks pretty unlikely that we’ll get skunked.” I arrived with telescope in hand at Seacrest Marina Park just before 6 a.m. on Monday, and the clouds were solid. I was soon joined by Ryan “Tortuga” Carpenter and a young man named Spencer who brought his home-made Dobsonian telescope to the party. For a while we just watched the clouds roll by.

It was well after 7 a.m. before we got our first glimpse of the Sun, and Mercury in transit—a fleeting look that lasted less than a minute. For the next hour or so we had several similar quick peeks at the transit when the Sun found a hole in the clouds.

We finally got some longer looks after 8 a.m., long enough to actually snap photographs of the transit. Then, right about 8:30, we suddenly had clear, blue skies. We had a few interruptions from clouds after that, but these were brief and we had close to constant viewing of the transit until it ended around 11:40 a.m.

Other areas didn’t have so much luck, especially those sites east of the city. The Seattle Astronomical Society had a transit-viewing event scheduled from one of its preferred observing sites at Snoqualmie Point Park, but had already canceled it by Sunday night because of inclement weather in the forecast. One member went there anyway and reported only brief views of the transit. Others reporting to the society’s Google forum, fittingly titled “Through the Clouds,” also noted limited success from Kent, Ellensburg, and Bellevue. The Green Lake neighborhood had decent weather and observers there reported more lengthy looks at the transit.

If you click on this photo to see the larger version you can see
Mercury just to the left of the center of the disk of the Sun, and
a sunspot cluster to the right. Taken with a Canon
PowerShot A530 through an 8-inch Dob at 48
power. Photo by Greg Scheiderer.

Our trio in West Seattle tried to do a little science, or at least figuring, at the end of the transit. We each clocked the time between third and fourth contact of the transit. Interestingly enough, our observations varied by about 15 seconds. Parallax doesn’t explain that; our telescopes were all set up within about 10 feet of each other! I would guess that the variation could be explained by differences in visual acuity, quality of telescope optics, and ability to find the start/stop button on the smartphone stopwatch. Carpenter did the math and said we were in the ballpark for determining the size of Mercury based on the length of time between the two contacts.

Mostly we just had fun seeing this rare celestial event, and sharing it with quite a number of interested passers-by. I chose the site because a lot of people are typically there, from those catching the West Seattle Water Taxi into the city to those just strolling in the park. Great weather was an unexpected bonus.

While there are only, on average, 13 transits of Mercury in a century, our next one is relatively soon: November 11, 2019. After that we’ll have to wait 13 years, until 2032, for another.

Southern Illinois: eclipse crossroads of America

Carbondale, Illinois is beating the odds. It’s said that, on average, a total solar eclipse can be seen from the same spot on Earth only once every 375 years. Carbondale will be getting two total solar eclipses in the next eight years, as the paths of the August 2017 and April 2024 events cross in southern Illinois. There’s little wonder that the area is billing itself as the “Eclipse Crossroads of America.”

“It’s a wonderful outreach opportunity,” said Bob Baer in something of an understatement. Baer heads up public astronomy programs at Southern Illinois University in Carbondale and is co-chair of its Solar Eclipse Steering Committee, which has been planning for the 2017 eclipse for almost two years already. Complicating their planning somewhat is the fact that the day of the 2017 eclipse, August 21, is also the first day of classes for fall semester at the university. (We hope all of the students will cut their 1 p.m. classes to see the eclipse!) They’ll have students moving in, parents still around, and as many as 50,000 extra eclipse chasers in the area.

“We’re planning on having events through the weekend and on Monday,” the day of the eclipse, Baer said, noting they’re shooting for edu-tainment—some science as well as entertainment. SIU athletic facilities will be key. They can accommodate a lot of people, and the university can link the big screens in their football stadium and basketball arena together. Baer said they’re working with NASA and their local PBS station, WSIU, to offer eclipse programming that day and to show coverage from other places along the eclipse path.

The local astronomy club, the Astronomical Association of Southern Illinois, is a relatively modest operation with only about 30 members, but president Harry Treece said they’ll be doing their part.

“We are going to be manning one of the stations at a state park near here called Giant City, hosting an area there for different astronomy clubs and people like that who can come in,” he said. Treece said he’s glad that the university is also reserving some space that won’t be so public for more serious astronomical observers.

“It will be a place for like-minded people who can set up their equipment, and there won’t be general public, lots of people, little kids running around knocking scopes over, and things like that,” he said.

Baer and Treece say there’s a lot to consider.

“Most of Southern Illinois is going to see the eclipse, so we’ve been holding workshops for about the last year,” Baer said. “These have been aimed toward communities, businesses, emergency personnel, and the cities to give them basic information on the eclipse and help them get started on planning.”
Treece added that they’ve urged cellular telephone companies to bring in temporary towers to handle the anticipated surge in traffic. The SIU athletics department is securing generators to make sure they have enough power to support larger crowds. Planners have gone as far as Chicago in search of enough porta-potties.

Accommodations and weather

Can the area handle so many visitors? Baer thinks so. He notes that there are about 3,000 hotel rooms within an hour or so of Carbondale, and most hotels in the area don’t take reservations for more than a year out. They’ll probably be snapped up in a hurry starting August 21 of this year. In addition, there are some 300,000 acres of public land in the region with plenty of camping in state parks and national forests.

As for the weather, it’s typically very hot and humid in August in Carbondale. It’s one of the reasons they’re making indoor venues available, so people can duck out of the heat. Baer said they often have morning clouds that clear by afternoon, and that it’s rare to have complete overcast. So they’re hopeful for good eclipse viewing in town.

Why Carbondale?

“Carbondale is going to be having a big, carnival-like atmosphere for the whole thing,” Treece said. “It’s a beautiful part of the country, there’s a lot to do a couple of days before or after.”

“We have a large number of wineries in southern Illinois,” as well as craft breweries, Baer said. “The center line of totality goes right through our two wine trails. It’s a great opportunity for a lot of local businesses and their venues to host things during the eclipse and leading up to it.”

“If people want to come to the area ahead of time, there’s plenty to do,” Baer added, noting that it’s easy to get around, so people can come early and explore before deciding where to go to watch the eclipse. He described an area along Route 3 headed to St. Louis, which is about 80 miles northwest of Carbondale as the crow flies.

“There are these beautiful limestone bluffs that overlook the Mississippi River,” Baer said. “Those areas down there, the bottom grounds and those bluffs, are excellent places to get and be in a flat area where you can see that 360-degree sunset effect that you get during an eclipse.” He said you might find an elevated spot from which you could see the Moon’s shadow sweeping across the Earth as it approaches from the west.

Eclipse science

Bob Baer. SIU photo.

With all of this going on, Baer is going to be doing some real science during the eclipse, too. He’s part of Citizen CATE (Citizen Continental America Telescopic Eclipse Experiment), a project that hopes to observe and shoot video of the corona of the Sun from 60 locations across the country during the eclipse.

“We’re looking at the evolution of the corona,” he said. “We can image the corona directly, and we can start to learn about how the magnetic fields of the Sun affect that solar corona.”

“We’re hoping to make a 90-minute movie from that so we can see the corona as it evolves,” he added.

Baer went to Indonesia for the total solar eclipse there in March, something of a trial run for Citizen CATE. It was his first total solar eclipse.

“It’s a bit of a life-changing experience,” he said, even though they knew what to expect. “Until you’ve experienced it, it really doesn’t sink in.”

We expect that millions of people will experience it for the first time in August 2017.