That’s what made the opportunity for Tech students to meet three astronauts — all three Georgia Tech graduates  — incredibly special.

Ahead of Georgia Tech’s Saturday matchup against Miami, three Yellow Jacket space veterans — Sandy Magnus, Col. Bill McArthur, and Col. Tim Kopra — took questions from students and shared the experiences that led them on their individual journeys.

Sandy Magnus (Ph.D., Materials Science and Engineering) was asked when she knew she wanted to be an astronaut.

“I loved physics in high school, but I discovered engineering in college. I didn’t know it existed before then,” Magnus said.  “I was like ‘Wow! This is cool! You can take the physics and do something with it.’”

Magnus says she followed her interests and where they led her.

“If you have a goal — whether that’s to be an astronaut or not — you need to go for it. You’ll never know unless you try. I didn’t want to be 50-years-old and look back at my life and wonder if I could have been an astronaut if I tried.”

Magnus flew two space missions, including the final mission of the Space Shuttle program.

Col. Bill McArthur earned his master’s degree in aerospace engineering from Georgia Tech before launching on four space missions with NASA. When asked about what areas of education students should focus on if they want to be astronauts themselves, McArthur had a bit of a surprise answer.

“Engineers hate this: grammar. You’ve got to communicate,” McArthur explained. "If you're going to orbit the earth a little geography is good too."

Next, an elementary school student asked the panel how flying in a space shuttle compared to flying in a plane.

Col. Tim Kopra (M.S. Aerospace Engineering), a past commander of the International Space Station said the space shuttle is a lot rougher than a plane, likening it to a really long amusement park ride.

“After landing, you hit so hard that you spend about 10 seconds doing an inventory to make sure nothing is broken,” Kopra said.  “That’s the longer answer to your question. Space flight is pretty darn cool.”

Under Secretary of Defense for Research & Engineering Mike Griffin also joined the Georgia Tech astronauts on the panel.

Georgia Tech has produced 14 astronauts — tied for second among public universities. These astronauts include John Young (B.S. Aerospace Engineering 1952), who walked on the moon and was on the first space shuttle. Col. Kopra was not the only Georgia Tech graduate to command the Space Station; Shane Kimbrough (M.S. Operations Research) followed in the same year. When Kimbrough flew on Endeavour in 2008, he was joined by Magnus and Eric Boe (M.S. Electrical Engineering 1997).

NASA has navigated our solar system with spacecraft and landers, but still, our celestial neighbors remain vast frontiers, particularly in the search for life. Now, an alliance of researchers will accelerate the quest to find it.

The NASA Astrobiology Program has announced the establishment of the Network for Life Detection, NFoLD, which connects researchers to pursue the detection of life and clues thereof on our neighboring planets and their moons. NFoLD includes an oceanic research alliance led by the Georgia Institute of Technology. 

It is called Oceans Across Space and Time, OAST, and has received a $7 million NASA Astrobiology grant with the long-range goal of extracting secrets from present and past oceans on Mars, Jupiter’s icy moon Europa, and Saturn’s moon Enceladus. But OAST will also ramp up the study of the conditions that spawned first life in Earth’s oceans.

“With OAST, we finally hit the perfect mix of people, science questions, and supporting activities to really go after some of the most important unknowns in astrobiology,” said Britney Schmidt, OAST’s principal investigator and an assistant professor in Georgia Tech’s School of Earth and Atmospheric Sciences.

NFoLD is one of five new Research Coordination Networks that the NASA Astrobiology Program has announced. The other RCNs pull together research communities that include the study of early Earth and its chemistry, evolution, distant habitable worlds, and exoplanet systems.

Yellow submarine on Europa 

Oceans Across Space and Time could one day help NASA put a submarine on a rocket to Europa to look for life in the ocean beneath its ice crust. Or OAST could join NFoLD colleagues to help NASA explore parched Martian landscapes that once were oceans.

But the path to our space neighbors leads through studying Earth. Field and lab experiments on our planet will divulge more knowledge about chemical and biological evolutionary strategies so that researchers can develop instruments and methodology that reliably detect signs of life on other planets and moons.

"We don't yet have a slam-dunk measurement that we could make on another planet to definitively say ‘this is life,’” said Schmidt, who coordinates OAST and led the application efforts to establish it. “OAST’s main goal is to take a suite of technologies into the field on Earth to make measurements side-by-side while returning samples to the lab to understand.” 

Then, when that is very finely honed, send it aloft.

Crucial target practice 

One of NFoLD’s goals is to participate in future astrobiology space missions from the start so that they can successfully identify target spots on other planets or moons where signs of life could actually be detected if present.

"A major challenge for life detection is where on a given planet or moon to look for life,” said Jeff Bowman, deputy principal investigator of OAST and an assistant professor at Scripps Institution of Oceanography at UC San Diego. “The density of life on our own planet extends across several orders of magnitude. Look for life in the wrong place and Earth could appear lifeless.”

OAST’s team has the expertise to bridge earthly data and celestial goals.

Many of its 18 co-investigators and their teams have already explored biogeochemistry in our own planet’s eons-old rock record, in the atmosphere, the oceans, and the icecaps with an eye to extrapolating the data to other worlds. Other OAST researchers have helped design Mars probes or build robotic submarines intended to one day dive into Europa’s subsurface ocean to detect life or at least a hint of it.

“OAST researchers have expertise in detecting and characterizing life in a variety of harsh environments like the Antarctic, the deepest ocean trenches, and lakes with extreme chemistry and salinity,” Bowman said. “We will leverage this expertise to understand how life may be distributed in different ocean environmental extremes around the solar system.”

Diverse member institutions

OAST includes investigators from Scripps Institution of Oceanography at the University of California San Diego; the University of Kansas; Louisiana State University; the Massachusetts Institute of Technology; Stanford University; the Blue Marble Space Institute of Science; the University of Texas; Colgate University; the University of California, the University of Central Florida; the University of Auckland; York University; the University of Otago, and the New Zealand National Institute of Water and Atmospheric Research.

“I'm particularly proud of the high number of women and pre-tenure scientists we've engaged through our project,” said Schmidt. Five leaders in OAST are women, and 12 researchers are early career or pre-tenure. The project will also support graduate and undergraduate students as well as postdoctoral researchers through the NASA Postdoctoral Program.

Like this article? Subscribe to our email newsletter

Also READ: Laughing Gas May Have Helped Warm Early Earth and Given Breath to Life

Research News
Georgia Institute of Technology
177 North Avenue
Atlanta, Georgia  30332-0181  USA

Media relations assistance: Ben Brumfield (404) 660-1408, ben.brumfield@comm.gatech.edu

Writer: Ben Brumfield

The observations, made by the IceCube Neutrino Observatory at the Amundsen–Scott South Pole Station and in coordination with telescopes around the globe and in Earth’s orbit, help resolve a more than a century-old riddle about what sends subatomic particles such as neutrinos and cosmic rays speeding through the universe.

Since they were first detected over one hundred years ago, cosmic rays—highly energetic particles that continuously rain down on Earth from space—have posed an enduring mystery: What creates and launches these particles across such vast distances? Where do they come from? 

Because cosmic rays are charged particles, their paths cannot be traced directly back to their sources due to the magnetic fields that fill space and warp their trajectories. But the powerful cosmic accelerators that produce them will also produce neutrinos. Neutrinos are uncharged particles, unaffected by even the most powerful magnetic field. Because they rarely interact with matter and have almost no mass—hence their sobriquet “ghost particle”—neutrinos travel nearly undisturbed from their accelerators, giving scientists an almost direct pointer to their source. 

Two papers published July 13 in the journal Science have for the first time provided evidence for a known blazar as a source of high-energy neutrinos detected by the National Science Foundation-supported IceCube observatory. This blazar, designated by astronomers as TXS 0506+056, was first singled out following a neutrino alert sent by IceCube on September 22, 2017. 

“The evidence for the observation of the first known source of high-energy neutrinos and cosmic rays is compelling,” said Francis Halzen, a University of Wisconsin–Madison professor of physics and principal investigator for the IceCube Neutrino Observatory. 

“The era of multi-messenger astrophysics is here. Each messenger gives us a more complete understanding of the universe and important new insights into the most powerful objects and events in the sky,” said NSF Director France Córdova. “Such breakthroughs are only possible through a long-term commitment to fundamental research and investment in superb research facilities.”

A blazar is a galaxy with a super-massive, rapidly spinning black hole at its core. A signature feature of blazars is that twin jets of light and elementary particles, one of which is pointing to Earth, are emitted from the poles along the axis of the black hole’s rotation. This blazar is situated in the night sky just off the left shoulder of the constellation Orion and is about four billion light years from Earth. 

“Scientifically, this is very good news,” said Ignacio Taboada, an associate professor in Georgia Tech’s School of Physics and member of the Center for Relativistic Astrophysics also at Georgia Tech. As leader of the “Transients Science Working Group” within IceCube, he oversaw all the studies that inquired on the correlation TXS 0506+056’s gamma ray flare and the neutrino alert of September 22, 2017. “For years, we’ve had a long list of potential sources for high-energy neutrinos. Now we have a specific source – blazars – that we can look at very carefully.” 

See the full feature article and video

Research News
Georgia Institute of Technology
177 North Avenue
Atlanta, Georgia  30332-0181  USA

Media Relations Contact: John Toon (404-894-6986) (jtoon@gatech.edu).
 

Kepler-186f is the first identified Earth-sized planet outside the solar system orbiting a star in the habitable zone. This means it’s the proper distance from its host star for liquid water to pool on the surface.

The Georgia Tech study used simulations to analyze and identify the exoplanet’s spin axis dynamics. Those dynamics determine how much a planet tilts on its axis and how that tilt angle evolves over time. Axial tilt contributes to seasons and climate because it affects how sunlight strikes the planet’s surface.

The researchers suggest that Kepler-186f’s axial tilt is very stable, much like the Earth, making it likely that it has regular seasons and a stable climate. The Georgia Tech team thinks the same is true for Kepler-62f, a super-Earth-sized planet orbiting around a star about 1,200 light-years away from us.

How important is axial tilt for climate? Large variability in axial tilt could be a key reason why Mars transformed from a watery landscape billions of years ago to today’s barren desert.

“Mars is in the habitable zone in our solar system, but its axial tilt has been very unstable — varying from zero to 60 degrees,” said Georgia Tech Assistant Professor Gongjie Li, who led the study together with graduate student Yutong Shan from the Harvard-Smithsonian Center for Astrophysics. “That instability probably contributed to the decay of the Martian atmosphere and the evaporation of surface water.”

As a comparison, Earth’s axial tilt oscillates more mildly — between 22.1 and 24.5 degrees, going from one extreme to the other every 10,000 or so years.

The orientation angle of a planet’s orbit around its host star can be made to oscillate by gravitational interaction with other planets in the same system. If the orbit were to oscillate at the same speed as the precession of the planet’s spin axis (akin to the circular motion exhibited by the rotation axis of a top or gyroscope), the spin axis would also wobble back and forth, sometimes dramatically.

Mars and Earth interact strongly with each other, as well as with Mercury and Venus. As a result, by themselves, their spin axes would precess with the same rate as the orbital oscillation, which may cause large variations in their axial tilt. Fortunately, the moon keeps Earth’s variations in check. The moon increases our planet’s spin axis precession rate and makes it differ from the orbital oscillation rate. Mars, on the other hand, doesn’t have a large enough satellite to stabilize its axial tilt.

“It appears that both exoplanets are very different from Mars and the Earth because they have a weaker connection with their sibling planets,” said Li, a faculty member in the School of Physics. “We don’t know whether they possess moons, but our calculations show that even without satellites, the spin axes of Kepler-186f and 62f would have remained constant over tens of millions of years.”

Kepler-186f is less than 10 percent larger in radius than Earth, but its mass, composition and density remain a mystery. It orbits its host star every 130 days. According to NASA, the brightness of that star at high noon, while standing on 186f, would appear as bright as the sun just before sunset here on Earth. Kepler-186f is located in the constellation Cygnus as part of a five-planet star system.

Kepler-62f was the most Earth-like exoplanet until scientists noticed 186f in 2014. It’s about 40 percent larger than our planet and is likely a terrestrial or ocean-covered world. It’s in the constellation Lyra and is the outermost planet among five exoplanets orbiting a single star.

That’s not to say either exoplanet has water, let alone life. But both are relatively good candidates.

“Our study is among the first to investigate climate stability of exoplanets and adds to the growing understanding of these potentially habitable nearby worlds,” said Li.

“I don’t think we understand enough about the origin of life to rule out the possibility of their presence on planets with irregular seasons,“ added Shan. “Even on Earth, life is remarkably diverse and has shown incredible resilience in extraordinarily hostile environments.

“But a climatically stable planet might be a more comfortable place to start.”

The paper, “Obliquity Variations of Habitable Zone Planets Kepler 62-f and Kepler 186-f,” is published online in The Astronomical Journal.

But for researcher Nicholas Hud, asteroids play an entirely different role: that of time capsules showing what molecules originally existed in our solar system. Having that information gives scientists the starting point they need to reconstruct the complex pathway that got life started on Earth.

Director of the NSF-NASA Center for Chemical Evolution at the Georgia Institute of Technology, Hud says finding molecules in asteroids provides the strongest evidence that such compounds were present on the Earth before life formed. Knowing what molecules were present helps establish the initial conditions that led to the formation of amino acids and related compounds that, in turn, came together to form peptides, small protein-like molecules that may have kicked off life on this planet.

“We can look to the asteroids to help us understand what chemistry is possible in the universe,” said Hud. “It’s important for us to study materials from asteroids and meteorites, the smaller versions of asteroids that fall to Earth, to test the validity of our models for how molecules in them could have helped give rise to life. We also need to catalog the molecules from asteroids and meteorites because there might be compounds there that we had not even considered important for starting life.”

Hud was a panelist at a press briefing “Asteroids for Research, Discovery, and Commerce” February 17 at the 2018 annual meeting of the American Association for the Advancement of Science (AAAS) in Austin, Texas. 

NASA scientists have been analyzing compounds found in asteroids and meteorites for decades, and their work provides a solid understanding for what might have been present when the Earth itself was formed, Hud says.

“If you model a prebiotic chemical reaction in the laboratory, scientists can argue about whether or not you had the right starting materials,” said Hud. “Detection of a molecule in an asteroid or meteorite is about the only evidence everyone will accept for that molecule being prebiotic. It’s something we can really lean on.”

The Miller-Urey experiment, conducted in 1952 to simulate conditions believed to have existed on the early Earth, produced more than 20 different amino acids, organic compounds that are the building blocks for peptides. The experiment was kicked off by sparks inside a flask containing water, methane, ammonia and hydrogen, all materials believed to have existed in the atmosphere when the Earth was very young.

Since the Miller-Urey experiment, scientists have demonstrated the feasibility of other chemical pathways to amino acids and compounds necessary for life. In Hud’s laboratory, for instance, researchers used cycles of alternating wet and dry conditions to create complex organic molecules over time. Under such conditions, amino acids and hydroxy acids, compounds that differ chemically by just a single atom, could have formed short peptides that led to the formation of larger and more complex molecules – ultimately exhibiting properties that we now associate with biological molecules.

“We now have a really good way to synthesize peptides with amino acids and hydroxy acids working together that could have been common on the early Earth,” he said. “Even today, hydroxy acids are found with amino acids in living organisms – and in some meteorite samples that have been examined.”

Hud believes there are many possible ways that the molecules of life could have formed. Life could have gotten started with molecules that are less sophisticated and less efficient than what we see today. Like life itself, these molecules could have evolved over time.

“What we find is that these compounds can form molecules that look a lot like modern peptides, except in the backbone that is holding the units together,” said Hud. “The overall structure can be very similar and would be easier to make, though it doesn’t have the ability to fold into as complex structures as modern proteins. There is a tradeoff between the simplicity of forming these molecules and how close these molecules are to those found in contemporary life.”

Geologists believe the Earth was very different billions of years ago. Instead of continents, there were islands protruding from the oceans. Even the sun was different, producing less light but more cosmic rays – which could have helped power the protein-forming chemical reactions.

“The islands could have been potential incubators for life, with molecules raining down from the atmosphere,” Hud said. “We think the key process that would have allowed these molecules to go to the next stage is a wet-dry cycling like what we are doing in the lab. That would have been perfect for an island out in the ocean.”

Rather than a single spark of life, the molecules could have evolved slowly over time in gradual progression that may have taken place at different rates in different locations, perhaps simultaneously. Different components of cells, for example, may have developed separately where conditions favored them before they ultimately came together.

“There is something very special about peptides, nucleic acids, polysaccharides and lipids and their ability to work together to do something they couldn’t have done separately,” he said. “And there could have been any number of chemical processes on the early Earth that never led to life.”

Knowing what conditions were like on the early Earth therefore gives scientists a stronger foundation for hypothesizing what could have taken place, and could offer hints to other pathways that may not have been considered yet. 

“There are probably a lot more clues in the asteroids about what molecules were really there,” said Hud. “We may not even know what we should be looking for in these asteroids, but by looking at what molecules we find, we can ask different and more questions about how they could have helped get life started.”

Research News
Georgia Institute of Technology
177 North Avenue
Atlanta, Georgia  30332-0181  USA

Media Relations Contact: John Toon (404-894-6986) (jtoon@gatech.edu).

Writer: John Toon