Tag Archives: Pacific Science Center

Grinspoon: Earth in human hands

David Grinspoon himself wonders how an astrobiologist wound up writing a book about the human impact on Earth. Grinspoon, author of Earth in Human Hands: Shaping Our Planet’s Future (Grand Central Publishing, 2016), answered the question during a Science in the City lecture recently at Pacific Science Center.

David Grinspoon

Astrobiologist and author David Grinspoon talked about his new book, Earth in Human Hands, January 10 at the Pacific Science Center. Photo: Greg Scheiderer.

“I am struck by the unique strangeness of the present moment,” Grinspoon said, noting that we are at the controls, if not actually in control, as we enter a new epoch in human history. Some find the proposed name of Anthropocene—the age of humanity—a touch self-centered or self-aggrandizing, but Grinspoon feels it is a fitting moniker.

“It represents a recognizable turning point in geological history brought about by one species: anthropos,” he said. “Our growing acknowledgement of this inflection point can be a turning point in our ability to respond to the changes we’ve set in motion.”

In fact, Grinspoon finds it promising that there’s some recognition that we the people are a major factor in what is happening.

“We need to learn all that we can about how planets work so we can make the transition from inadvertently messing with Earth to thoughtfully, artfully, and constructively engaging with its great systems,” he said.

A long history of planetary change

Grinspoon noted that it’s always fruitful to take a close look at the long-term history of Earth.

“We are not the first species to come along and radically change the planet and cause problems for the rest of the biosphere,” he said. In fact, the first one was not nearly so clever as we are. About 2.5 billion years ago the humble cyanobacteria caused a terrible calamity.

“They transformed the planet, the most radical chemical transformation that our planet has ever experienced,” Grinspoon explained. “They flooded the atmosphere with a poison gas that spelled certain doom for most of the other species that were living on the planet at that time.”

What they learned to do was photosynthesis, and the poison gas they spewed was oxygen. The oxygen also destroyed much of the warming methane in the atmosphere of the time, which led to a global glaciation that turned Earth into a giant snowball, a condition that lasted until volcanoes pumped out enough carbon dioxide to warm the planet up again.

“Cyanobacteria presumably never discussed that fact that they were starting to ruin the world,” Grinspoon quipped.

Four types of change

Grinspoon identifies four broad types of planetary change:

  • Random
  • Biological
  • Inadvertent
  • Intentional

The classic example of the random is an asteroid strike, something that just happens that there’s little control over. The cyanobacteria fall under the biological change. We’re in the midst of great inadvertent change right now, with automobiles, population growth and other factors driving a spike in carbon dioxide levels that began in the 1950s.

We’ve barely dipped our toes into the intentional. Grinspoon explained that our first stab at intentional change came with regard to fixing the hole in Earth’s ozone layer. The solution came from scientists studying Venus and trying to explain the planet’s lack of oxygen. They realized that chlorine destroys oxygen and ozone. Other scientists connected the dots and concluded that chlorofluorocarbons in refrigerants, propellants, and other products on Earth were eating away at our planet’s ozone layer.

Fixing the ozone

Interestingly, Grinspoon noted that this created an argument that may sound familiar. Some called the notion a hoax, there were attempts to discredit it, opposing “science” was created, and there was lengthy debate.

“The truth won out,” Grinspoon said. A global agreement was reached: the Montreal Protocol. Alternate chemicals were developed that didn’t deplete the ozone. Grinspoon said it’s working.

“It’s still going to be another fifty years or so because it takes time for the ozone layer to come back,” he said. “The natural chemical reactions that re-create ozone take fifty to one hundred years.”

“Assuming we stay on track, this is actually a success story, and it’s an existence proof that this kind of global change is possible,” Grinspoon added. “Not that it’s easy, and there are some ways in which fixing global warming will be inherently harder than this, but it shows that we are capable of a different approach.”

Thinking long term

While global warming is an important challenge, Grinspoon said it is a relatively short-term one, and that we need to think even further down the road. He said such random events as asteroid strikes don’t have to happen.

“We have a space program; the dinosaurs didn’t, and look what happened to them!” he quipped. We know how to identify possible threats and have a pretty good idea about what to do when they occur.

Further, Grinspoon said that we have an illusion that climate is always more-or-less fine, only because we’ve been lucky enough to live in a time of relative stability. We need to think about the next ice age, which he said will eventually occur.

“If we get over the near-term climate harm that we’re doing, we will have the knowledge that will allow us, when the need arises—we’re talking 10,000 or maybe even as much as 50,000 years in the future—we’ll have the ability to interrupt that cycle of ice ages and preserve the relatively benign climate, not just for ourselves but for other species as well,” Grinspoon said.

Who is out there?

All of this allowed Grinspoon to put on his astrobiologist hat and talk a little about the search for extra-terrestrial intelligence (SETI).

“When you do the math of SETI what you realize is that the question of is there anybody out there to talk to comes down to the question of longevity,” he said. “You can show this mathematically, that if civilizations last for a long time—that is, if this problem is soluble of how to create a stable technological civilization and use technology in the service of survival rather than self destruction—if that’s possible to do and if it happens on other planets, then there ought to be other civilizations out there that we could discover and maybe even communicate with.”

Thus the Anthropocene epoch represents something of a turning point. There are those who regard it as doom and gloom, as something we can’t beat, but Grinspoon doesn’t see it that way.

“The true Anthropocene is something that should be welcomed,” he said. “Though it is yet only in its infancy, it can be glimpsed. Don’t fear it; learn to shape it.”

“It is the awareness of ourselves as geological change agents that, once propagated and integrated, will provide us with the capacity to avoid doom and take our future into our own hands,” Grinspoon concluded.


Books by David Grinspoon:

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Solstice sunset watch and LIGO info on our calendar this week

The calendar year is winding down, and astronomy clubs are hustling to get a last few events in before we plunge into 2017.

Rose City AstronomersThe Rose City Astronomers eschew their usual formal meeting for their annual holiday potluck at 6:30 p.m. Monday, December 19 at the OMSI auditorium in Portland. Leftovers from the event have traditionally been donated to a homeless shelter, and this year the astronomers are also collecting warm clothing for donations, figuring that astronomy folk may have a supply of such to bring comfort to those late-night sessions at the eyepiece.

The Eastside Astronomical Society will hold its monthly meeting at 7 p.m. Tuesday, December 20 at the Lake Hills Library in Bellevue. NASA Solar System Ambassador John McLaren will give a talk about the history of scientific exploration of the Sun, and look ahead to future efforts to learn even more about our nearest star.

Seattle Astronomical SocietyThe Seattle Astronomical Society will hold its monthly meeting at 7:30 p.m. Wednesday, December 21 in room A102 of the Physics/Astronomy building on the University of Washington campus in Seattle. Joey Key, a professor at the University of Washington-Bothell, will talk about the next LIGO run searching for gravitational waves, which will also involve astronomical collaboration is search of an elusive “multimessenger source,” a signal that could be detected both in gravitational waves and electromagnetic radiation. Interesting stuff!

Vikings

VMMEPPThe Viking Mars Missions Education and Preservation Project plans an informal information session for 4 p.m. Tuesday, December 20 at the Hillsdale Library in Portland. This family-friendly event will feature artifacts from the Viking mission, activities for kids, and lots of information about Viking history. Check out our recent article and podcast about the project. The year end is a good time to lend a little financial support to this great history project, too!

Solstice sunset watch

Join Alice Enevoldsen of Alice’s Astro Info and watch the first sunset of winter at 3:45 p.m. Wednesday, December 20 at Solstice Park in West Seattle. The solstice is at 2:44 a.m. PST on Wednesday. Sunset that evening is officially listed as 4:20 p.m., but Enevoldsen says they’ve noted that it’s typically about ten minutes early because of the horizon at that spot. She gives a fun and informative presentation about the mechanics of the seasons, and is persistent about it—this will be her thirty-first seasonal sunset watch. That’s a lot of solstices and equinoxes! Come by even if it’s cloudy, because the Sun sometimes sneaks through anyway, but driving rain makes it a no-go.

Futures file

You can scout out future astronomy events on our calendar. The page also features a full schedule of planetarium and stage science shows at Pacific Science Center.

Up in the sky

The Ursid meteor shower peaks this week. This Week’s Sky at a Glance from Sky & Telescope magazine and The Sky This Week from Astronomy offer more observing highlights for the week.

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Club events and planetarium shows on tap for this week

The first weekend in December is heavy with club events, star parties, and planetarium shows. Here’s what’s on the calendar for the coming week:

Club gatherings

Spokane Astronomical SocietyIn December many astronomy clubs opt out of a formal meeting and instead hold a banquet or other more social gathering. The Spokane Astronomical Society plans its annual potluck dinner for 6 p.m. Friday, December 2 at the Riverview Retirement Community. A guest speaker will follow the dinner at 7:30. Dr. John Buchanan, a professor of geology at Eastern Washington University, will talk about catastrophic outburst flooding that have occurred on Earth and Mars through geologic time. He will examine how the “Ice Age Floods” in eastern Washington compare with various large floods both on Earth and Mars.

Seattle Astronomical SocietyThe Seattle Astronomical Society plans its free monthly public star parties for 6 p.m. Saturday, December 3 at two locations: Green Lake in Seattle and Paramount Park in Shoreline. Poor weather will mean cancellation of the events, so watch the club’s website and social media for updates.

Tacoma Astronomical SocietyThe Tacoma Astronomical Society will hold one of its free public nights at 7:30 p.m. Saturday, December 3 at the Fort Steilacoom campus of Pierce College. The all-weather program will be about selecting gift telescopes, binoculars, and other astronomy gear. (We covered that topic, too last week!) If the weather is good they’ll also put their gear into action for some celestial observing.

Planetarium shows

Planetaria have no trouble with cloudy weather! There are several shows on the docket for the week.

The University of Washington planetarium will host three free shows on Friday, December 2 at 5:30, 6:30, and 7:30 p.m. Reservations for all three times were snapped up quickly, but you can watch this site to see if tickets become available.

Pacific Planetarium in Bremerton will host its First Friday Sky Walk shows December 2, with a presentation every half-hour between 5 p.m. and 7:30 p.m. The shows look at what’s up in the sky for the coming month.

There are a variety of shows suitable for all ages every day at the Willard Smith Planetarium at the Pacific Science Center. You’ll find their complete schedule on our calendar page.

Futures file

You can scout out future astronomy events on our calendar. New additions to the calendar this week include:

Up in the sky

Venus and the Moon make a nice pairing on the evening of December 3. This Week’s Sky at a Glance from Sky & Telescope magazine and The Sky This Week from Astronomy offer more observing highlights for the week.

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Proxima Centauri b and the question of habitability

The discovery of evidence of a planet in orbit around our nearest stellar neighbor, Proxima Centauri, has people all agog and with good reason. It’s something of a misnomer, however, to call the exoplanet Proxima Centauri b “Earth-like.” Rory Barnes, a professor in the Department of Astronomy and the Astrobiology Program at the University of Washington, points out that the planet’s mass is probably somewhere between 1.3 and five times that of Earth.

Barnes

UW prof. Rory Barnes speaking at an Astronomy on Tap Seattle event earlier this year. Photo: Greg Scheiderer.

“There’s a lot of excitement about this planet because it is so close in mass to the Earth, but we don’t actually know if it’s even rocky like the Earth,” said Barnes during a recent talk at the Pacific Science Center. Barnes, who uses computer modeling to study the habitability of exoplanets, noted that even though Proxima Centauri is the next closest star, it’s still pretty far away at 4.24 light years. If the Sun were the size of a baseball resting on home plate at Safeco Field, Barnes said Proxima Centauri b would be a grain of sand in New York City. Still, he noted there’s understandable excitement about the discovery.

“The reason why I think that this is the biggest exoplanet discovery since the discovery of exoplanets is because it is still very close, at least relatively speaking,” Barnes said. “We really have a chance, with this planet, to potentially observe its atmosphere and its surface and maybe start to try and sniff out the presence of life on that planet. Or not. We don’t know yet. But being so close, it gives us a shot.”

Not really “like” Earth

While Proxima Centauri b is about the mass of Earth, plenty else is different. It’s twenty times closer to its home star than Earth is to the Sun, and goes around that star in just 11.2 days. We know little else about it. The star has just 12 percent of the mass and 14 percent the radius of the Sun, and its brightness is just one one-thousandth that of the Sun.

“This is a small, dim star,” Barnes said.

Is there life there?

Life requires energy, some bioessential elements, and liquid water. The energy and elements are abundant in the universe, so Barnes says the key to finding life elsewhere is liquid water.

“When we think about exoplanets, we’re really going to focus, at least for now, on surface water,” Barnes said. “Not only is it going to be easier to see, but it’s going to be more similar to the Earth and that gives us a better shot at maybe being able to interpret the observations that we’re going to get.”

The desire to find liquid surface water on a planet led us to the concept of the “habitable zone” around a star, an area where the temperature would be right for liquid water to exist. Barnes said Proxima Centauri b is smack in the middle of the habitable zone.

“This is a dream planet for those of us who study this field,” he said, but added a caveat: “Being in the habitable zone does not mean you’re habitable. It is just the first step we need to get to.”

“The habitable zone is jargon, and it’s really misleading,” Barnes added. “I apologize for my field for inflicting it on you!”

Barnes said there are several threats to habitability for planets orbiting M dwarf stars like Proxima Centauri. With the habitable zone so close to the star, there is potential that stellar flares could blow away the atmosphere of a planet within it. Planets that close are probably tidally locked, too, but this isn’t a deal-breaker; their atmospheres might distribute heat and energy effectively. Tidal heating could cause problematic volcanism.

Habitable zone chart

Barnes showed this chart demonstrating that while Proxima Centauri b is now within the habitable zone, the zone was once much further from the star.

The biggest threat to the habitability of Proxima Centauri b, according to Barnes, is that its star was once much bigger and brighter before it contracted into the dim, red phase it is in today. In the early years that would have meant that its habitable zone was out at a distance between .25 and .5 astronomical units, while Proxima Centauri b orbits at a mere .05 AU. Being so far inside the habitable zone after formation means that the planet could have lost all of its water and become a completely uninhabitable place like Venus. On the other hand, if Proxima Centauri b formed as something like Neptune, being so close to the star could have blasted away its hydrogen envelope.

“Maybe that planet could have actually transformed from an uninhabitable Neptune-like planet into a rocky planet like the Earth,” Barnes speculated. “This is what we at the University of Washington think is probably the best bet for how this planet could be habitable.”

Barnes is hopeful that the discovery of Proxima Centauri b will help boost support for the sorts of telescopes and observatories that can make the observations needed to learn more about this intriguing exoplanet and determine if it is habitable, and even inhabited.

While Barnes won’t give the odds of life there—there are way too many variables and so little we know right now—he sounds confident that we’ll find life somewhere. He noted that we’ve found life on Earth in the deep sea, extreme deserts, extreme cold, acidic environments, and under other harsh conditions.

“The realization that extreme life is everywhere is part of the astrobiological revolution that is occurring right now in science,” Barnes said. “This recognition that life finds a way gives us confidence as we go forward.”

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Annual Moon viewing festival highlights week’s calendar

The last installment of the Pacific Science Center’s Science Café series and an annual Moon viewing festival are the high points of this week’s astronomy events calendar.

Viewing the Moon

Seattle Japanese GardenThe popular annual Moon Viewing Festival at the Seattle Japanese Garden will be held beginning at 6 p.m. Saturday, September 17 at the garden, which is within the Washington Park Arboretum in Seattle. The evening will include music, a haiku contest, and a traditional Japanese Tea Ceremony. Volunteers from the Seattle Astronomical Society will be on hand with telescopes to offer a great, close-up view of the Moon. Unfortunately, as of this writing the event is sold out.

Farewell to the science café

Pacific Science CenterThe Pacific Science Center is discontinuing its Science Café program after more than ten years at The Swiss Restaurant & Pub in Tacoma, Wilde Rover in Kirkland, and, up until a year or two ago, T.S. McHugh’s in Seattle. The center plans to have many of the same sorts of speakers and topics at its new, onsite Science in the City lectures.

One final astronomy-themed science café remains on the calendar and will be held at The Swiss at 6:30 p.m. Tuesday, September 13Josh Krissansen-Totton of the University of Washington Astrobiology Program and Department of Earth and Space Sciences will give a talk titled “The Search For Life Beyond Earth.” Krissansen-Totton will go beyond the headlines and explore how astronomers and astrobiologists are trying to detect life on exoplanets, and when they’re likely to be successful. Admission is free. Bring questions; there’s always plenty of time for Q-and-A.

OAS meets

Olympic Astronomical SocietyThe Olympic Astronomical Society will hold its monthly meeting at 7:30 p.m. Monday, September 12 in room Art 103 at Olympic College in Bremerton. They plan to make a comet, among other activities.

Futures file

You can scout out future astronomy events on our calendar. New additions this week include:

Up in the sky

September often offers great weather for stargazing as it’s still typically fairly warm in the evenings but the nights are getting longer. This Week’s Sky at a Glance from Sky & Telescope magazine and The Sky This Week from Astronomy have observing highlights for the week.

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Wednesday astronomy at UW

Most of the week’s astronomy activity is focused on a couple of events Wednesday at the University of Washington.

Seattle Astronomical SocietyThe Seattle Astronomical Society will hold its monthly meeting at 7:30 p.m. Wednesday, June 15 in room A102 of the Physics/Astronomy building on the Seattle campus. Society member John McLaren will give a presentation about solar exploration, covering early human interactions with the Sun and their unexpected impacts on our growing technology. He’ll discuss how we learned about the Sun before the space age, what we’ve since discovered from space-based observing, and what the future holds for solar observations from space. The meeting is open to the public.

TJO goes retrograde

Theodor Jacobsen Observatory

Photo: Greg Scheiderer.

After the SAS gathering you’ll have just enough time to dash up campus to one of the twice-monthly open houses at the Theodor Jacobsen Observatory, which begins at 9 p.m. With both Mars and Saturn in the retrograde parts of their orbits, the observatory director, Dr. Ana Larson, will talk about what that means, will discuss the historical context, and help visitors plot the motion of Mars against the background stars using a star map.

With both planets well placed for viewing, hope for clear skies and at peek at them through the observatory’s vintage telescope, operated by volunteers from the Seattle Astronomical Society.

Planetaria

The Willard Smith Planetarium at Pacific Science Center has several astronomy shows every day. Check our calendar for the schedule.

Pacific Planetarium in Bremerton will offer public shows on Friday, June 17, with hourly presentations at 5 p.m., 6 p.m., and 7 p.m. The topic will be star hopping: how to explore the heavens using the constellations and stars as a guide. Admission to the shows is $5.

Up in the sky

Jupiter, Mars, and Saturn all remain well placed for evening viewing these days, but there’s plenty more to see. The Sky This Week from Astronomy magazine and This Week’s Sky at a Glance from Sky & Telescope have other observing highlights for the week.

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AstronoMay continues at PacSci with two talks this week

Saturday was Astronomy Day, but the Pacific Science Center is taking the whole month to celebrate AstronoMay! Two interesting talks highlight the calendar for the week.

Brett Morris

Brett Morris

Brett Morris, one of the co-founders of Astronomy on Tap Seattle, will give a presentation titled, “Hunting For Life in the Universe” at a Teen Science Café at 7 p.m. Wednesday, May 18 at the center’s PACCAR IMAX Theater. Morris will introduce the science of astrobiology and how it seeks to measure and locate the conditions necessary for life in the universe. He’ll talk about telescopes and techniques used to explore other worlds and to try to track down life on them.

Dr. Will Grundy, the lead investigator for the surface composition team of New Horizons, will give a talk titled, “Pluto and Charon Up-close” at 2:15 p.m. Sunday, May 22 at the PACCAR Theater. Grundy will show close-up images from the mission and discuss his research, which involves icy outer solar system planets, satellites, and Kuiper belt objects using a broad variety of observational, theoretical, laboratory, and space-based techniques.

Volunteers from the Seattle Astronomical Society will be on hand at the center Saturday and Sunday with solar telescopes for viewing of the Sun. AstronoMay also includes planetarium shows, screenings of the movie A Beautiful Planet 3D, and other activities. Check the AstronoMay calendar page for a full listing.

Club events

saslogoThe Seattle Astronomical Society will hold its monthly meeting at 7:30 p.m. Wednesday, May 18 in room A102 of the Physics/Astronomy building on the campus of the University of Washington in Seattle. Solar System Ambassador Ron Hobbs will give a talk titled, “Juno to Jupiter: Piercing the Veil.” The Juno spacecraft will arrive at Jupiter in July. Over the ensuing year and a half, it will peer through the Jovian cloud tops and provide a deeper understanding of the composition and structure of the Solar System’s largest planet. Hobbs will explain what exciting science to expect from NASA’s latest outer planet mission.

Rose City AstronomersRose City Astronomers will hold their monthly meeting at 7:30 p.m. Monday, May 16 at the OMSI auditorium in Portland. It will be the group’s annual astronomy fair, with a swap meet, info booths, and brief show-and-tell sessions.

TJO open house

Theodor Jacobsen ObservatoryThere will be an open house at the University of Washington’s Theodor Jacobsen Observatory at 9 p.m. Wednesday, May 18. Students Cale Lewandowski and Jason Busnardo will be giving a talk about how to overcome the challenges of a trip to Mars. Reservations are strongly recommended for the talks, which are held in a small classroom in the observatory and often fill up early. Volunteers from the Seattle Astronomical Society will offer tours of the observatory and a look through its vintage telescope if weather permits.

Up in the sky

Mars is nearing opposition and Jupiter remains well placed for observing. This Week’s Sky at a Glance from Sky & Telescope magazine and The Sky This Week from Astronomy have other observing highlights for the week.

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