Surviving Trump’s budget

Donald Trump

By Travis Metcalfe

Last week the Trump administration sent an initial 2018 budget plan to Congress, which proposed dramatic spending reductions for most federal agencies. The deepest cuts targeted the Environmental Protection Agency (EPA) and programs related to climate science at the National Oceanic and Atmospheric Administration (NOAA). Congress must ultimately approve the final budget, and there is widespread skepticism that legislators will endorse Trump’s priorities. But what if there were a way for the agencies to absorb the proposed cuts while simultaneously encouraging innovation and stimulating collaboration within federally funded labs?

The centerpiece of the White House budget plan is to add $54 billion in military spending by making cuts to all other discretionary programs. About two-thirds of the nation’s $4-trillion budget pays for mandatory spending, such as Social Security and Medicare benefits. The majority of what’s left goes to the military, while the remainder supports all other federal agencies. Without increasing the deficit, adding $54 billion to the $550 billion defense budget would require a 10% cut to the rest of the government. In Trump’s budget, the reductions are not distributed evenly: the EPA is slashed by 31%, while NOAA might face a cut of 17%.

Although reactions to Trump’s budget plan have been largely unfavorable, even among conservatives, the new administration clearly intends to scale back support for federally funded labs. After years of enduring stagnant and even slightly declining budgets, the labs have already streamlined their operations. They have no easy way of absorbing large budget cuts without sacrificing essential facilities and personnel that provide valuable services to the public. In the shadow of this uncertain budgetary future, it might be time for federal labs to treat their scientific staff more like university professors.

Perhaps because universities operate on an academic schedule, faculty positions are typically 9-month contracts, just like public school teachers. Those who are satisfied with a 9-month salary can spread it over the entire year, but universities allow professors to seek external funding to support their research during the summer. By contrast, staff scientists at federally funded labs generally have 12-month contracts, so they can focus their efforts on the priorities of their government sponsors. This stability allows federally funded scientists to work on issues that are higher-risk or longer-term than typical grant-funded projects. But it also reduces the incentives for innovation and collaboration, qualities that are implicitly nurtured in researchers who rely on grant funding.

I worked as a staff scientist at NCAR for six years before my position was lost to a previous round of budget cuts. For the past five years, I have raised all of my support by writing grant proposals to government agencies and private foundations. The “sink or swim” reality of working entirely on grant funding is not something that I would recommend to anyone, particularly in the current funding climate. But it forced me to be more innovative and collaborative than I might have been otherwise. Based on my experience at NCAR, and now looking from the outside, I believe that full-time federal sponsorship may actually stifle these virtues in many excellent scientists.

Federally funded labs could give themselves budget flexibility without eliminating jobs by offering staff scientists a 9-month instead of 12-month contract. Like university professors, researchers could optionally seek external funding from government or commercial sources to restore their previous salaries. This may dilute the research focus dictated by their federal sponsors, but that consequence is unavoidable with any substantial budget cuts. The silver lining to this approach is that it would reward innovation and stimulate collaboration inside and outside the laboratories, while encouraging public-private partnerships to maintain essential facilities and services.

Whether or not Trump’s budget is greeted with enthusiasm in the halls of Congress, federally funded labs and the public could benefit from renegotiating the contracts of staff scientists. Once the change is implemented, the labs could reallocate existing funds to hire new junior scientists in every research area — something that hasn’t been possible for years. In one stroke, they would establish incentives for seeking outside funding, encourage innovation, stimulate collaboration, and inject fresh talent into their organizations. It may be a tough sell for the current staff, but the ends would justify the means.

Catching the solar eclipse

Path of the 2017 total solar eclipse

By Travis Metcalfe

More than a century ago, Albert Einstein proposed a new theory of gravity, suggesting that concentrations of matter warp the underlying fabric of space, like a bowling ball sitting on a trampoline. If he was correct, light passing near the sun should be deflected slightly, shifting the apparent positions of background stars. During a total solar eclipse in 1919, British astronomer Arthur Eddington made the historic measurements that confirmed Einstein’s theory.

And next summer, anyone with a high-end digital camera can repeat the experiment as the shadow of the moon sweeps across the country on August 21, 2017.

Unlike a lunar eclipse, opportunities to see a total solar eclipse are relatively rare. Lunar eclipses occur up to several times a year, and anyone on the night side of the planet can watch the full moon get darker as it passes through the shadow of the Earth. Partial solar eclipses happen almost as frequently as lunar eclipses, but they can only be seen from specific places, often in the middle of the ocean. A total solar eclipse, when the moon passes directly in front of the sun and blocks it out entirely for a few minutes, can only be seen from within the 70-mile wide shadow cast by the moon. The last time this happened in the United States was 1979, and most of the country won’t see one again until 2045.

The path of the total solar eclipse next summer stretches from Oregon to South Carolina. Around 11:30 a.m. on August 21, the shadow of the moon will speed across Grand Teton National Park. Seven minutes later, it will pass over Casper, Wyoming and then sweep through Nebraska from northwest to southeast in less than 20 minutes. Anyone near the center line will see twilight around the entire horizon for just over two minutes. The hot gas that surrounds the sun will cast an eerie silver light punctuated by a ring of pink magnetic loops. Bright stars and planets will briefly become visible in the sky.

“It looks like the end of the world,” says Doug Duncan, director of the Fiske Planetarium in Boulder. “It starts to get cold, and animals start to freak out and do strange things. It’s almost like you’re in a dream.”

Duncan relocated to Boulder in 2002 from Chicago, where he had worked at the Adler Planetarium for 10 years. He has traveled all around the globe to see 10 total solar eclipses, and he now leads educational trips to bring large groups of people to these events. He started preparing for the 2017 eclipse several years ago, and he will host an event with more than 250 people at the Jackson Lake Lodge in Grand Teton National Park.

From Colorado, the nearest places to see the total eclipse are in Wyoming and Nebraska. About 93 percent of the sun will be blocked out from Boulder, but a three-hour drive north on I-25 to Glendo, Wyoming will put you right on the center line. If you prefer Nebraska, a four hour drive on I-76 and I-80 to North Platte will get you into the shadow, and another half hour north to Stapleton will make the darkness last 40 percent longer. Duncan suggests that there is no comparison between the partial eclipse that can be seen from Boulder and the total eclipse just a few hundred miles away.

It would be like hearing a live concert of your favorite band from the parking lot at Red Rocks, instead of going inside to see it for yourself.

“I wouldn’t be surprised if 100,000 people all decided to drive I-25 that morning, headed for Wyoming,” Duncan predicts. The eclipse is on a Monday, so he recommends that people head north over the weekend and enjoy a campsite or small-town hotel to avoid the rush. Although the total eclipse will only last for a few minutes, the entire event will play out over several hours. The sun will start to be covered by the moon earlier in the morning, and after the total eclipse it will gradually get brighter into the early afternoon. Do yourself a favor: bring water, sunscreen and a hat. Most importantly, you’ll need some special eclipse glasses.

“McGuckin has the best record of any hardware store in the country of providing eclipse glasses for people,” Duncan says. During a partial solar eclipse in 2012, they sold 10,000 pairs for $2 each.

Another total solar eclipse will come to the United States in 2024, but it will start in Texas and pass through several Midwest states before hitting New England. It will be nearly 30 years before the next one in our region, which will pass right through Colorado in 2045. If you’re feeling lucky, make your hotel reservations now in Colorado Springs. Otherwise, don’t miss this chance to confirm Einstein’s theory of gravity for yourself, or simply enjoy the surreal spectacle of a slowly vanishing sun.

Juno reaches Jupiter

Artist concept of the Juno mission to Jupiter

By Travis Metcalfe

In Roman mythology, Jupiter is king of the gods and his wife Juno is the queen. Jupiter was known for his infidelity, so Juno was always keeping an eye on him. In one story, Jupiter fell in love with a priestess named Io and tried to conceal their affair with a veil of clouds. The goddess Juno peered through the clouds and revealed Jupiter’s true nature. With a name inspired by this myth, NASA’s Juno spacecraft arrived at Jupiter in early July and will spend the next 18 months peering through the clouds to discover its inner secrets.

“We’re going to fly past Jupiter up close, measure the gravity field, the magnetic field, as well as the microwaves coming from the deep interior,” says Fran Bagenal, professor in the Department of Astrophysical and Planetary Sciences at the University of Colorado and a team leader for the Juno mission.

Bagenal first came to Boulder in 1987 as a visiting scientist at NCAR’s High Altitude Observatory, and she joined the faculty at CU in 1989. She has been involved with Juno since the beginning. She now leads one of the three primary working groups that are responsible for conducting science experiments during the mission.

The Juno spacecraft was built right here in Colorado by Lockheed-Martin, and it was launched from Cape Canaveral in August 2011. Although it was strapped to the largest available Atlas-V rocket, the launch alone didn’t give it enough momentum to reach Jupiter. Instead, it flew out beyond the orbit of Mars and then whipped past Earth again in 2013 to get a gravitational boost that pushed it into the outer solar system. It made headlines last month on July 4, when it finally reached Jupiter and slowed itself down enough to be captured by the planet’s gravity, a maneuver known as orbit insertion.

Most missions to the outer solar system rely on nuclear power to operate at large distances from the sun. A radioisotope thermoelectric generator uses heat produced by the radioactive decay of plutonium-238 to create power. This is not the type of plutonium that is used for weapons, but it can only be manufactured in nuclear reactors.

When Juno was being designed, the United States was running out of plutonium-238, so the mission needed to find another power source. Despite the fact that sunlight is only 4 percent as intense at Jupiter as it is on Earth, improvements in the efficiency of solar panels allowed the mission to operate on just 200 watts of power from three arrays, each measuring 9 by 29 feet.

“There’s nothing like having to go to another planet to design equipment that is super energy efficient,” Bagenal says. “I believe that’s one of the big payoffs that comes with space exploration.”

Unlike previous missions to Jupiter, Juno will orbit over the north and south poles of the giant planet. This will allow it to pass very close to the cloud tops while avoiding radiation belts above the equator that would damage sensitive electronics on board. It made the first close pass when it arrived at Jupiter last month.

After making a couple of longer orbits, in October it will begin orbiting every two weeks, gathering information for several hours during each close pass and transmitting the data to Earth when it is further away.

Juno will map the gravitational field of Jupiter to probe its inner structure, it will use microwaves to determine the water content of the atmosphere and it will study Jupiter’s northern and southern lights to understand the planet’s magnetic field. These experiments are designed to answer key questions about the structure and formation of planets, not only in our own solar system but also around other stars.

“Jupiter played a major role in solar system formation, possibly also in bringing water to the Earth,” Bagenal explains. “If we knew how our solar system formed and the role of Jupiter in that process, we could begin to compare it to other solar systems.”

The spacecraft is designed to endure the radiation environment near Jupiter for up to 37 orbits, but even a handful of close passes are expected to solve some of the planet’s most important mysteries. Whenever the mission ends, Juno is scheduled to make a controlled descent and burn up in the atmosphere of Jupiter. The purpose of this fiery exit is to avoid any possibility of contaminating Jupiter’s icy moon Europa, which has a sub-surface ocean that scientists believe may harbor life.

Stay tuned as local scientists help unlock the secrets of the king of planets.

Boosting solar physics

The DKI solar telescope under construction in Maui

By Travis Metcalfe

Shortly after the financial crash of 2008, Congress passed the American Recovery and Reinvestment Act (ARRA) to stimulate the economy with $787 billion in government spending on public infrastructure. Although controversial at the time, ARRA was later credited with saving or creating millions of jobs during the Great Recession. The National Solar Observatory (NSO) received $146 million in ARRA funding to help build the largest solar telescope in the world on a mountaintop in Maui, a $344 million project that may not have moved forward without the stimulus. The investment sparked a chain of events that ultimately moved NSO staff from Arizona and New Mexico to the new headquarters in Boulder this year.

The Advanced Technology Solar Telescope (ATST) was nearing its final design review in early 2009, after more than six years of development. Federal science funding had been slowly declining since 2004, so it was unclear whether construction of a large new facility would be feasible. The National Science Foundation (NSF) was already planning to shut down some older solar telescopes. With ATST moving forward, the NSO decided to consolidate its operations to one site. In early 2010, they issued a request for proposals to host the new headquarters. The University of Colorado Boulder was one of seven organizations to respond, and in late 2011 our city was selected over the other finalist in Huntsville, Alabama.

Boulder has been a national hub for solar physics since Harvard astronomer Walter Orr Roberts founded the High Altitude Observatory (HAO) in 1940. Our first solar observatory was absorbed into NCAR when it was established 20 years later. With the announcement in 2011 that Boulder would soon be home to a second solar observatory, local scientists wondered how long it would take members of Congress to call for a merger of the two organizations. The role of NCAR in climate science made it particularly vulnerable, with numerous politicians looking for ways to slash the budget. The relocation of NSO to Boulder may have been seen as an unprecedented opportunity to cut out a portion of NCAR and give it to solar physicists whose research had less political impact. So far, the concerns have been unwarranted.

With ATST under construction in Maui, the NSF wanted to inspire a new generation of solar physicists to enter the field. Hosting the NSO headquarters at a university was a strategic decision. Historically, most solar physicists worked at federally funded laboratories rather than universities. As a consequence, relatively few students were being trained in the field, and the demographics of solar physics meetings started to resemble a retirement seminar. The NSF subsidized the creation of faculty positions in solar physics across the country, and the University of Colorado enticed the NSO to relocate to Boulder in part by promising to hire several new faculty positions related to solar physics.

“By bringing in students, I think we will be able to support NSO in a way that would not have been possible in other cities,” says Axel Brandenburg, visiting professor in the Department of Astrophysical and Planetary Sciences at CU. Brandenburg first came to Boulder in 1992 to work as a postdoctoral fellow in the High Altitude Observatory at NCAR. He has spent the past 15 years working at research laboratories in Denmark and Sweden, but he jumped at the chance to return to Boulder last year for a rotating three-year faculty position in solar physics, created by CU as part of their agreement with the NSO. Earlier this month the university hosted a solar physics meeting for the American Astronomical Society. “The overall attendance was dominated by young people,” Brandenburg says, suggesting that the plan is already working.

Construction of the new telescope in Maui has encountered some resistance from native Hawaiian groups. Although several telescopes were already on the site, the peak where ATST would be located was considered sacred by some indigenous groups. “I think it is important to be aware of these concerns and to work with the indigenous people to make it something positive for both sides,” Brandenburg says. In 2013, the project was officially renamed the Daniel K. Inouye Solar Telescope (DKIST) to honor the late senator from Hawaii who had a strong record of support for fundamental scientific research, and astronomy in particular. Brandenburg explains that in Hawaii everyone knows DKI, almost like JFK in the rest of the country.

When it begins regular operations in 2020, DKIST will be the largest solar telescope in the world. It promises to revolutionize observations of the sun’s magnetic field, which are essential for understanding and predicting the explosive events that create space weather for our planet. The building that will house the telescope and instruments is now complete, and the team is beginning to integrate the major optical systems. The main mirror has a diameter of 4 meters (13 feet), and will generate 13 kW of power at the focus of the telescope, so heat management will be crucial. Local scientists expect DKIST to usher in a new era of solar physics. With NSO headquarters now in Boulder, and CU committed to training a new cadre of students, we can expect our city to remain a national hub for solar physics well into the future.

Igniting space weather

The Northern Lights are caused by space weather events

By Travis Metcalfe

In March 1989, a powerful eruption from the Sun slammed into the Earth’s magnetic field and took down a regional power grid in Canada, plunging the entire province of Quebec into darkness. Although such dramatic examples of “space weather” are relatively rare, the Sun emits a steady stream of radiation and charged particles that have the potential to disrupt our increasingly technological society. Boulder is home to the Space Weather Prediction Center (SWPC) at NOAA, as well as numerous scientists at the National Solar Observatory and NCAR who study the root causes of solar eruptions and their resulting impacts on our planet.

When Galileo projected the Sun through his telescope, he marveled at the dark spots that littered its surface. We now know that these sunspots are areas where the magnetic field is stronger, making the spot cooler and darker than its surroundings. Careful records of sunspots over decades revealed a regular rise and fall in the number of spots every 11 years. This is the most visible manifestation of an underlying magnetic cycle in the Sun, where the magnetic bubbles that appear as sunspots at the surface are periodically stretched out, reorganized and recycled by rotation and other motions deeper in the interior.

Although solar eruptions can happen at anytime, they are stronger and more frequent around the peak of the Sun’s magnetic cycle. As the magnetic field around sunspots emerges from the surface, it sometimes gets twisted and tangled with the field of neighboring spots. This can create sudden bursts of energy, ejecting hot gas out into the solar system.

Such events are a spectacular sight for NASA telescopes when they happen on the east or west limb, but they evoke different emotions when they occur on the side of the Sun that is pointed directly at Earth. A few days after an eruption, charged particles will slam into the Earth’s magnetic field, spiral into the atmosphere near the poles, and interact with oxygen and nitrogen to produce shimmering curtains of light in the sky.

“Everyone is aware of the northern lights and how beautiful they are. That’s something that I have always been captivated by,” says Ryan McGranaghan, a recent PhD in the Aerospace Engineering program at University of Colorado at Boulder. After coming to Boulder in 2011, McGranaghan collaborated with scientists at NCAR’s High Altitude Observatory (HAO) as well as SWPC at NOAA while working on his doctoral thesis. He now has a fellowship to work at NASA’s Jet Propulsion Laboratory in Pasadena starting next year. He credits a class taught by HAO research associate Delores Knipp for sparking his interest in space weather.

“All of this energy from the Sun is coming into our atmosphere and having adverse effects on the safety of our space infrastructure,” he says. “The more we’ve started to rely on technologies that are space-based, the more susceptible we’ve become to space weather.”

Some readers may remember a time when we used printed maps and road signs to find our way from one place to another. In the age of the smart phone, the Global Positioning System (GPS) is now integrated into our lives. It’s easy to forget that GPS relies on a network of 24 orbiting satellites that communicate with receivers on the ground. Space weather events can distort GPS signals as they travel through the atmosphere, reducing the accuracy of your calculated position.

Similar problems can arise with many types of satellite communications, including increasingly popular satellite radio and television signals. But the impacts of the associated radiation can extend beyond these inconveniences. After strong solar storms, astronauts on the International Space Station take extra precautions and commercial airlines are diverted to lower-latitude routes to avoid dangerous exposure.

If you’d like to learn more about space weather, McGranaghan will be speaking at this month’s Ignite Boulder event. Ignite presentations are often compared to TED talks, but they have a unique format. Each speaker has 5 minutes to present 20 slides that are set to advance automatically every 15 seconds. The concept originated in Seattle, but it has now been replicated at thousands of events around the world.

“The American Geophysical Union now does an Ignite event, and I’ve also been to one at NCAR,” says McGranaghan. The local events take place several times a year at Boulder Theater, and have always sold out. All of the talks are eventually posted online, so you can watch until the next solar eruption brings down the power grid.

Chasing alien megastructures

Comets swarming around KIC 8462852

By Travis Metcalfe

In 1960, physicist Freeman Dyson suggested that the energy demands of all technological civilizations would eventually exceed the natural resources of their home planet. Continued development would require that they build enormous structures in space to capture more of the energy released by their sun, a concept now known as a Dyson sphere. Such structures might be found if they temporarily blocked some starlight, or if they glowed with excess heat. Combing through observations from NASA’s Kepler space telescope, astronomers at Yale University recently found a mysterious signal they can’t yet explain, and the internet is buzzing with the idea that it might be an alien megastructure.

For the past several years, Tabetha Boyajian has helped organize the efforts of astronomy enthusiasts through Yale’s Planet Hunters project. The idea was to enlist thousands of eyeballs to look for interesting signals from the 150,000 stars that the Kepler telescope was searching for planets. The Kepler team used computer algorithms to sift through all of the observations, so Planet Hunters was a hedge against the possibility that the computers might miss something interesting. The algorithms were great at finding the expected signals, but they were no match for the human brain when it came to finding the unexpected.

Kepler measured the brightness of each target star every half hour for four years. A few percent of the targets showed the expected signal, small dips in light that appeared when a planet passed in front of the star for several hours during each orbit. The rest of the targets showed myriad ways that stars can change their brightness over time, from explosions and flares to spots and pulsations. But one star defied categorization: KIC 8462852, also known as Tabby’s star. For most of the four years its brightness stayed remarkably constant, until halfway through the mission when 15 percent of the light disappeared for nearly a week. Just before the end of the mission it happened again, with several large dips spread over a few months.

Whatever blocked the starlight was too big and too irregular to be a planet. Jupiter would only cover 1 percent of the sun’s light, and it would create the same dip at regular intervals for each orbit. Boyajian and her team recently published a scientific paper outlining the evidence for and against the many possible explanations. Their best guess is that it may have been a swarm of comets, but they still can’t rule out an alien megastructure. To unravel this mystery they need more observations, but Kepler stopped monitoring the star in 2013.

“The fact that the star is varying in brightness unpredictably suggests that you’d really like to watch it as continuously as you can,” says Tim Brown, principal scientist for the Las Cumbres Observatory Global Telescope (LCOGT) network. Brown moved to Boulder in 1972 for graduate studies in astrophysics at the University of Colorado. He spent most of his career working at NCAR, until a unique opportunity arose in 2006. An old friend had recently retired from a highly successful career working for several technology companies, and he dreamed of building a robotic observatory with telescopes all around the planet. Brown spent the next seven years turning that dream into a reality.

LCOGT now has 18 robotic telescopes on six continents, and operates them as a single scientific instrument. “If you have something that changes with time, then we’re interested,” Brown says. Traditional observatories are ill-equipped to study time-variable phenomena. Brown suggests an analogy with a dentist’s office: You set up an appointment six months in advance, show up on the specified day and get the work done. But LCOGT is more like a fast food restaurant: You show up whenever you like, order what you want, and get it almost immediately.

Although it was originally conceived as a private facility, LCOGT now sells some of its telescope time to other astronomers who need its unique capabilities. Users simply specify what observations they want and when they should be executed. The request is submitted to an automated queue system, and a notification is sent by email when the observations are completed. With observatories all around the globe, there are always telescopes under dark skies. As long as it isn’t cloudy, observations are happening 24/7. If you need to measure the brightness of a star once a day for a few years, LCOGT is pretty much the only facility that can do it.

Which brings us back to Tabby’s star. Boyajian and her team are launching a Kickstarter campaign in early May. Their goal is to raise funds for telescope time on LCOGT. The idea is to keep an eye on the brightness of KIC 8462852, searching for additional dips that may identify the source of the mysterious signal found by the Kepler telescope.

“Almost everybody is interested in what’s going on in the sky at an instinctive level,” Brown says. “If you can find a way to harness that natural interest and gather a few pennies from everybody who owns an iPhone, it would make a huge difference in the funding picture for astronomy.”

Planet Hunters crowd-sourced the discovery of the most mysterious star in the galaxy, and now Boyajian will crowd-fund new observations with LCOGT to find out whether it is surrounded by a swarm of comets or an alien megastructure. Even Freeman Dyson would be impressed by the convergence of technologies that made all of this possible.

Tracking killer asteroids

Meteor contrail in Chelyabinsk

By Travis Metcalfe

In December 2004, astronomers in Arizona discovered an asteroid the size of a cruise ship that appeared to be on a collision course with Earth. Initial observations of the space rock, known as Apophis, suggested that it had a very good chance of striking our planet in 2029. Later measurements ruled out this impact, but left open the possibility of a near miss in 2029 that would change the orbit slightly for a direct hit in 2036. Thankfully, NASA continued to track Apophis and has now eliminated the possibility of an impact anytime soon.

Predicting the path of an asteroid is a bit like forecasting the trajectory of a hurricane. At any moment in time we can measure the position, speed and direction of motion. There are always uncertainties in each of these measurements.

Projecting forward in time, the range of possible locations only expands, leading to the cone-like forecasts issued by the National Hurricane Center. There is value in providing advance warning to potentially affected areas, even as new observations gradually refine the predictions. Just as changing conditions in the atmosphere and ocean can alter the path of a hurricane, gravitational tugs from the planets can modify the orbit of an asteroid. So continued tracking of potential threats is highly recommended.

“My own take on this is that protecting the planet is a long-term commitment,” says Marc Buie, a staff scientist at Southwest Research Institute in downtown Boulder. Buie relocated to Colorado in 2008 after working for 17 years at Lowell Observatory in Flagstaff, Arizona. During his career, he’s helped discover thousands of objects in all parts of the solar system.

He is currently involved in an effort led by the B612 Foundation to launch a privately-funded space telescope called Sentinel, which is designed to track asteroids that may threaten the future of humanity.

“There are lots of ways that we can get smacked around by nature, and this one is actually preventable,” he says.

Unlike hurricanes, the season for killer asteroids never ends.Earlier this month an object known as “2013 TX68” sailed past the planet at a distance 10 times further than the moon. As the name might suggest, it was just discovered a few years ago and could only be tracked for several days before disappearing into the darkness of space.

From these limited observations, astronomers knew it would return around the first week of March 2016, but the closest approach could have been anywhere from a few times Earth’s radius to 35 times the distance to the moon. There was never a significant danger that it would collide with Earth, but an asteroid the size of a basketball court could certainly cause some damage.

Just ask the people of Chelyabinsk. In mid-February 2013, a space rock about half the size of 2013 TX68 entered the atmosphere above this industrial city in southern Russia.

Moving at 40,000 miles per hour, the object exploded in a spectacular air-burst more than 18 miles above the city, with only small pieces eventually reaching the ground.

The scene was captured by numerous dashboard cameras and surveillance videos, showing several bright flashes and a persistent contrail illuminated by the morning sun.

There was just enough time for startled residents to flock to their windows before the shock wave hit a few minutes later, a sonic boom that sent glass flying into thousands of buildings and injured more than 1,500 people.

“We’ve been proposing a new kind of survey instrument that will find more of these objects,” Buie says.

He’s been working with the B612 Foundation and locally with Ball Aerospace to design Sentinel, an infrared space observatory that will complement the capabilities of telescopes on Earth. The goal over the next decade is to catalog 90 percent of the dangerous asteroids, roughly down to the size of a football field. “Sentinel and B612 is all about warning time,” he says. “We want to give more than just duck and cover warning.”

What would we do if we found another asteroid like Apophis, but we couldn’t rule out an impact in the future? Although it might make a better Hollywood script, blowing up an incoming asteroid just creates several smaller problems on roughly the same trajectory.

With enough warning time, there’s no need for such a drastic response. By covering the dark surface of an asteroid with something highly reflective like talcum powder, the increased push from sunlight will slowly modify its orbit. Eventually, a probable impact turns into a near miss.

The population of potentially dangerous asteroids larger than a football field is currently estimated at 20,000 or more, but only a small fraction have already been discovered. Small investments to identify and track these objects over the coming decades will give humanity the advance warning we need to avoid an unexpected catastrophe.

Launching Commercial Spaceflight

SNC Dream Chaser

By Travis Metcalfe

Imagine boarding a brand new Boeing 747 on your way to Seattle. When you reach your destination a few hours later, after unloading the passengers and cargo, the pilots taxi the aircraft past the end of the runway and dump it into Puget Sound. For the return trip, you board another pristine 747 that will be discarded at the end of the flight. Can you imagine the price of your seat? Although it sounds ridiculous, this basic economic model has been the foundation of most spaceflight until recently.

Aside from the Space Shuttle, the rockets that lift payloads and people into orbit generally tumble back to Earth and fall into the ocean. Even the Mercury and Apollo capsules that brought the astronauts home were often recovered at sea and never reused. But with the Space Shuttle retired since 2011, and the skyrocketing cost of traveling to the International Space Station (ISS) with the Russians, NASA is now encouraging private companies to innovate and drive down the costs of spaceflight.

“The launch costs are really what make it expensive to fly in space,” says Steve Lindsey, senior director of space exploration systems at Sierra Nevada Corporation (SNC) in Louisville. Lindsey earned a degree in engineering sciences from the U.S. Air Force Academy in Colorado Springs before becoming an astronaut at NASA and flying on five Shuttle missions over the past two decades. He now oversees the development of a commercial spacecraft called the Dream Chaser at SNC, which NASA recently contracted to deliver cargo to the ISS. The Dream Chaser looks like a miniature version of the Space Shuttle, but with folding wings that allow it to be mounted at the top of a rocket.

“Instead of landing in the water or out in the desert, we can actually land on a conventional runway,” Lindsey says. SNC is one of several private companies that are developing the next generation of vehicles to send cargo, astronauts and even tourists into space. Technology headlines over the past few months have been peppered with the accomplishments of commercial spaceflight pioneers.

In November, a company called Blue Origin launched a rocket booster and capsule from a spaceport in Texas, ascended to the edge of space more than 60 miles above the surface of the planet and then gently landed it back in Texas about 10 minutes later. Last month they reused the same rocket booster to repeat the suborbital trek.

Not to be outdone, Elon Musk’s SpaceX venture launched a two-stage rocket from Florida in December. After separation, the first stage returned to a soft landing on the launch pad while the second stage delivered 11 satellites into orbit. The theme of these achievements is clear: If you can reuse expensive rocket hardware, the launch costs might decrease substantially.

The development of commercial spaceflight over the past two decades has been stimulated by two main factors. When Charles Lindbergh made the first non-stop flight from New York to Paris in 1927, he won the $25,000 Orteig prize. In hindsight, the prize was an important motivation that accelerated the development of commercial air travel. The 1996 announcement of the $10 million Ansari X Prize had a similar influence on commercial spaceflight, challenging private companies to send a crew of three people to the edge of space twice within two weeks. A team led by aerospace engineer Burt Rutan won the X Prize in 2004, and their technology is now licensed by Richard Branson’s budding space tourism company Virgin Galactic. Other than some wealthy individuals who hitched a ride into orbit with the Russians, space tourism is still in the realm of science fiction for now.

This brings us to the second factor. After the Columbia disaster in 2003, NASA didn’t launch another Space Shuttle until 2005. There was a lot of work remaining to complete the ISS, so NASA continued flying the Space Shuttle until 2011. At the same time, Russia operated their Soyuz spacecraft to send cosmonauts, astronauts and tourists back and forth between Earth and the ISS. In 2006, they charged NASA $22 million for each seat on the Soyuz.

When the Shuttle retired in 2011, the price jumped to $43 million. The current contract with the Russians, which expires at the end of 2017, shells out $71 million per seat. To avoid the escalating prices, NASA has awarded a contract to SpaceX and Boeing to provide crew transport to the ISS beginning in late 2017.

Although SNC in Louisville was passed over for the crew contract, they have continued to develop a crewed version of the Dream Chaser. “At full capacity, it could carry up to seven crew members,” Lindsey explains. The combination of reusable rockets from SpaceX and a soft-landing crew vehicle like the Dream Chaser has the potential to transform the economics of space travel. You may not be able to book a weekend getaway in an orbiting space hotel just yet, but considering how far airline travel has come in the past century, your chance may be just around the corner.

Engineering the climate

Phytoplankton bloom near Argentina

By Travis Metcalfe

Last month at a conference in Paris, 195 countries adopted a landmark agreement on how to respond to the Earth’s changing climate. The agreement included an ambitious goal to prevent the average global temperature from rising more than 1.5°C (2.7°F) above pre-industrial levels.

Prior to the conference, most of the countries had submitted pledges outlining how much they intended to reduce their emissions of heat-trapping pollution beginning in 2020. They also agreed to assess and revise their national plans every five years, an essential step given that the existing pledges are insufficient to achieve the 1.5-degree goal.

The challenges laid out in the “Paris Declaration” can be addressed with aggressive investments in renewable energy technologies. But if we fail to act quickly, we may also need to evaluate strategies for artificially cooling the planet until our transition away from fossil fuel begins to help.

Since the industrial revolution, the average global temperature has increased by about 1°C (1.8°F). The collective actions of several generations resulted in the release of so much heat-trapping pollution that it exceeded the capacity of the Earth’s oceans and forests to absorb it. The surplus pollution from each year remains in the atmosphere, and commits humanity to some amount of climate change for as long as it takes the planet to work through the accumulated excess.

Even if we eliminated all human-induced sources of this pollution right now, the globe would continue to warm for at least the next 50 years.

Our decisions about how to respond to the threat of climate change will only affect how much warmer the planet will get, and how long it will take to return to its natural temperature for future generations. The good news is that most scientists believe it is still possible to reverse climate change, and the required transition can be made gradually over several decades.

Doug Arent is a scientist at the National Renewable Energy Laboratory (NREL) in Golden. He was born and raised in Colorado, and remembers when Jimmy Carter established what was then called the Solar Energy Research Institute in 1977.

“I’ve focused my whole career on clean energy and sustainability,” he says. Arent watched intently on Nov. 29 when, on the opening day of the climate conference in Paris, President Obama announced that 20 countries including the United States would double their public funding for renewable energy research and development over the next five years. At the same time, Microsoft cofounder Bill Gates introduced the “Breakthrough Energy Coalition,” a private group that promised to invest billions of dollars of their own money in renewable energy technologies.

A company in Arizona is developing one example of the next-generation renewable energy that might benefit from this expansion in public and private investment. REhnu Solar manufactures large mirrors that track the sun and concentrate its light onto small solar cells that are extremely efficient but relatively expensive.

“That’s a technology that NREL has been involved with for decades,” Arent says. Each module can produce as much electricity as three rooftop solar panels, but it also functions as a solar water heater by recycling heat generated by the concentrated sunlight.

The current design mounts up to eight mirrors on each sun-tracking platform. These high-efficiency solar cells are constantly improving, so the modules at the focus of each mirror are designed to be replaceable. Using this technology, it is easy to imagine large areas of the Arizona desert converted into inexpensive solar electricity farms, displacing power plants that burn fossil fuel.

Ideally, we will transition away from fossil fuel quickly enough to avoid the most serious consequences of climate change. But considering the extreme weather events that have already resulted from the current level of warming, we might also want a backup plan.

Simone Tilmes is a scientist at the National Center for Atmospheric Research (NCAR), where she studies the impacts of “climate engineering” — strategies that artificially counter the warming effect of excess heat-trapping pollution in the atmosphere. The idea of climate engineering emerged from observations of volcanic eruptions, which push tiny particles into the upper atmosphere that have a temporary cooling effect on the planet. Essentially, these particles prevent some of the incoming sunlight from reaching the surface of the Earth.

Tilmes and her colleagues use computer models to examine how the climate system might react to a slightly fainter sun. She emphasizes that such measures should be seen as transitional strategies to help regulate the temperature of the planet in the short-term. But they aren’t a substitute for addressing the root causes of the problem.

Another concept for engineering the climate involves artificially enhancing the capacity of the ocean to absorb heat-trapping pollution. Small-scale experiments have already been performed, seeding the ocean with iron to stimulate the growth of microscopic plants that capture carbon dioxide and release oxygen.

A more extreme option proposes to release genetically engineered bacteria into the oceans, which have been specifically designed to absorb global warming gases. All of these strategies raise the questions of who will decide which options — if any — should be used, and what level of climate disruption would justify such an emergency response.

There is now a broad consensus that the Paris agreement is a solid first step to begin addressing climate change. With public and private forces aligned to kickstart the transition to renewable energy, there is hope that we can avoid dangerous levels of warming and create a sustainable future for the next generation. But it is comforting to know that if the transition is too slow, or if the projections are wrong, scientists are also developing options for a climate intervention.

Searching for sister Earth

Earth and Kepler-452b

By Travis Metcalfe

In last year’s blockbuster movie Interstellar, Matthew McConaughey leads a team of astronauts on a quest to find a new planet like Earth, after humanity collectively destroys the climate on the only home we’ve got.

Setting aside the feasibility of interstellar space travel, the good news is that astronomers have made great strides over the past two decades in their search for planets like Earth around other stars. Some of the most important breakthroughs have actually occurred right here in Boulder, and scientists at University of Colorado Boulder are currently developing technologies that will help measure the atmospheres of Earth-like planets in the future.

For most of history, we only knew about five other worlds in our solar system: Mercury, Venus, Mars, Jupiter and Saturn. The Greeks called them “planets” (a word meaning “wanderers”) because these bright lights in the sky were constantly moving against the backdrop of fixed stars. The more distant planets had to wait for the invention of the telescope. Uranus was discovered by a British astronomer in 1781, while the existence of Neptune was predicted by a French mathematician and confirmed in 1846. The first planet around another star like the Sun wasn’t discovered until 1995. It was comparable in size to Jupiter but 100 times closer to its sun, exerting a tiny gravitational tug that astronomers could measure.

By 1999, dozens of planets had been discovered around other stars, and for the first time astronomers found one that passed directly in front of its parent star, causing a brief eclipse of the starlight. Harvard graduate student David Charbonneau was working on his doctoral thesis in Boulder with Timothy Brown, then a senior scientist at the National Center for Atmospheric Research (NCAR). Brown had built a specialized instrument for the project — on a tight budget he had even ground the telescope optics himself in his garage in Louisville. Together they used the instrument to survey some stars that were suspected of having large planets, hoping that one of them would fortuitously be aligned such that the planet would periodically pass in front of its star.

They set up the telescope in the back parking lot of the NCAR laboratories, and in late 1999 they saw a Jupiter-sized planet pass in front of its star on two separate occasions.

This discovery paved the way for NASA’s Kepler space telescope, which was approved just two years later. The mission was designed to find small planets like the Earth using the technique pioneered by Brown and Charbonneau.

Kepler was built by Ball Aerospace in Boulder. It is the size of a small car, with a mirror less than half the diameter of Hubble’s. It used a 95 megapixel digital camera to snap new images every 30 minutes and measure the brightness of 150,000 stars, hoping that a few percent would show tiny eclipses from planets.

After launching from Cape Canaveral in 2009, Kepler spent the next four years staring at one small patch of the summer Milky Way. A planet like Earth would only block out one-tenth of a percent of the starlight for several hours as it passed in front of its star once a year. Kepler provided an unblinking eye to discover these small planets, and it found them in droves. Among the thousands of planets it discovered, about a dozen are nearly as small as Earth and orbit at a distance from their star where liquid water could exist. These planets are just from the 150,000 stars that Kepler surveyed. Our galaxy has a few hundred billion stars, so there must be millions of planets similar to the Earth!

Just because a planet is small and orbits at the right distance from its star doesn’t mean it would be a nice place to live. To get a better idea of how hospitable these planets might be, scientists at CU’s Center for Astrophysics and Space Astronomy (CASA) are working on a way to get direct images of the newly discovered worlds.

The basic concept has already been demonstrated. Block out the light of the star and look for light from the orbiting planets. This is fine for large planets like Jupiter that orbit far from their star. But to get images of Earth-like planets that are 10 billion times fainter than their sun, you need a “star-shade” — a large disk shaped like a flower that can position itself between the star and a telescope. Some engineering challenges remain, but CASA scientists Anthony Harness and Webster Cash hope to see the first images of Earth-like planets within a decade. Pass that light through a prism, and you can probe the composition of the atmosphere, maybe even see the signature of green plants.

As in the movie Interstellar, it’s been a long journey to find other planets like Earth. Without ever leaving our planet, astronomers and engineers around Boulder have pushed forward the discovery that small planets are the rule rather than the exception, and that potentially habitable worlds are peppered throughout the galaxy. The technology to measure their atmospheres is just around the corner. But even after we’ve found sister Earth, the prospects for mass migration are dim. Better not wreck our own planet just yet.