[unable to retrieve full-text content]
Europa is an ice-encrusted moon of Jupiter with a global ocean flowing underneath its surface. NASA is planning a mission soon that will look for signs of possible life there.
Now, a new finding from old data makes that mission even more tantalizing.
In recent years, the Hubble Space Telescope has spotted what looks like plumes, likely of water vapor, reaching more than 100 miles above the surface.
The plumes, if they exist, could contain molecules that hint at whether Europa possesses the building blocks of life.
In a study published Monday in the journal Nature Astronomy, scientists are reporting a belated discovery that Galileo, an earlier NASA spacecraft that studied Jupiter, appears to have flown through one of the Europa plumes more than 20 years ago. And that occurred close to one of four regions where Hubble has observed plumes.
“That’s too many coincidences just to dismiss as ‘There’s nothing there’ or ‘We don’t understand the data,’” said Robert T. Pappalardo, the project scientist for NASA’s upcoming Europa Clipper mission, which may launch as soon as 2022. “It sure seems like there’s some phenomenon, and plumes seem consistent.”
Galileo, which launched in 1989, arrived at Jupiter in 1995 and spent almost eight years examining the planet and its moons until its mission ended with a swan dive into Jupiter in 2003.
During a flyby of Europa on Dec. 16, 1997, instruments on Galileo measured a swing in the magnetic field and a jump in the density of electrons. At the time, scientists noted the unusual readings, but they did not have an explanation.
Then, in 2005, another spacecraft passing by another moon around another planet made a startling observation.
NASA’s Cassini spacecraft — which completed its mission last September — found geysers of ice crystals erupting out of Enceladus, a small moon of Saturn. Enceladus, it turns out, also has an ocean of liquid water under its ice.
That spurred renewed curiosity about Europa and whether it too might burp bits of its ocean into space. The Hubble first recorded signs of possible plumes in 2012, then again in 2014 and 2016. But at other times, Hubble has looked and seen nothing. That suggests the plumes are sporadic.
Last year, Melissa A. McGrath, a senior scientist at the SETI Institute in Mountain View, Calif. who was not involved in the new study, took a look at some radio experiments conducted by Galileo which examined how signals bent as Europa passed between Earth and the spacecraft. The experiments showed Europa possesses an atmosphere.
Some of the flybys indicated a higher density of particles near the surface — possible plumes. Before heading to a meeting of scientists working on the Clipper mission, a thought occurred to Dr. McGrath: “Gee, I really should check to see if any of them line up with any of the claimed plume detections,” from Hubble.
One of them indeed did.
Margaret G. Kivelson, an emeritus professor of space physics at U.C.L.A. who was the principal investigator for Galileo’s magnetometer, was at Dr. McGrath’s talk. She remembered the odd magnetic readings from 1997.
For years, she had been thinking of taking another look at the data for signs of plumes, but, “there are always other things to do,” she said.
Then she did.
“With the Hubble data in hand,” Dr. Kivelson said, “we had an idea of how big a plume might be reasonable. That we could translate into how long it would take Galileo to move across a plume that had been proposed.”
The three-minute-long magnetic anomaly seemed to fit with the apparent size of the Hubble plume.
Next, they turned to William S. Kurth, an astronomer at the University of Iowa who headed Galileo’s plasma wave experiment, which listened to the radio waves generated as charged particles bobbed back and forth along magnetic fields around Jupiter and its moons. That instrument also noticed a burst of radio waves during the flyby — and it occurred right in the middle of the magnetic anomaly.
The final piece was a computer model of a plume by Xianzhe Jia, a professor of climate and space sciences and engineering at the University of Michigan, that created the same effects on the magnetic field and the plasma waves.
“It all seemed to hang together,” Dr. Kivelson said.
The location was close, though not exactly the same, as the site Dr. McGrath reported. But Dr. McGrath said the new paper was convincing. “They did a really good job of the modeling and made a strong case,” she said.
Also convinced is John Culberson, a Texas congressman who is chairman of the House subcommittee that sets NASA’s budget. Mr. Culberson has been an enthusiastic supporter of the Clipper mission, repeatedly adding more money to the project than NASA officials requested. He has also been pushing for a follow-up mission that would land on Europa and drill into the ice.
At a subcommittee meeting last week, Mr. Culberson handed out the article, which was not yet available for public discussion, to his colleagues. “It’s worth noting that the scientific journal Nature Astronomy just reported that the Galileo mission, back in 1997, flew through a water plume on Europa,” he said. “So, the ocean of Europa is venting directly into outer space.”
The scientists were amused as they were not allowed to talk publicly about their findings yet. “That was really funny, because we’ve been so careful,” Dr. Kivelson said. “And all of sudden, Representative Culberson is throwing around the paper on the table. Very funny.”
Astronomers will certainly be taking more looks at Europa with the Hubble, trying to better understand how often the plumes erupt.
Dr. Pappalardo said it might be possible to adjust the trajectory of Europa Clipper so that at least one of the more than 40 planned flybys pass over a potential plume site. But that would have to be weighed against other science goals and how much fuel would be needed to nudge the spacecraft’s trajectory.
“Obviously this is a place we would want to suss out with the Europa Clipper mission in the future,” he said. “I think this is going to make for a lively debate at our next science mission meeting.”
A European Space Agency spacecraft, called Juice or Jupiter Icy Moons Explorer, will also fly by Europa, as well as two other Jovian satellites, Ganymede and Callisto. It could also launch as soon as 2022.
[unable to retrieve full-text content]
In the class that I teach on the history of the digital revolution, the students discuss whether innovation is driven more by big government projects or by nimble entrepreneurs. The answer, of course, is that it usually involves a symbiotic mix, like the semiconductor industry, which arose out of the Pentagon and NASA’s need to put guidance systems in the nose cones of rockets. Vannevar Bush was the dean of engineering at the Massachusetts Institute of Technology, a co-founder of Raytheon, and oversaw the government science programs that resulted in the atom bomb and electronic computer. He wrote a seminal paper in 1945, called “Science — the Endless Frontier,” which described how a collaboration of all three sectors he had been part of — academia, business and government — would drive innovation. Government funding of basic research in university labs would lead to discoveries in fundamental science that would be the “seed” for future inventions.
Many innovations have progressed along that path. The ENIAC computer funded by the United States Army and built at the University of Pennsylvania was the genesis for UNIVAC and then most other electronic computers. The network funded by the Defense Advanced Research Projects Agency and designed by a consortium of academic and private labs led eventually to today’s internet. The National Science Foundation, started based on Vannevar Bush’s paper, created a multiagency Digital Library Initiative that funded the academic research of Larry Page and Sergey Brin, which led to Google. The sequencing of the human genome, largely funded by the National Institutes of Health, planted the seeds for the biotech industry.
Now space endeavors are following this “innovation progression,” as we can call it. “Just as Darpa served as the initial impetus for the internet and underwrote a lot of the costs of developing the internet in the beginning, it may be the case that NASA has essentially done the same thing by spending the money to build sort of fundamental technologies,” Musk said a year after launching SpaceX. “Once we can bring the sort of commercial, free enterprise sector into it, then we can see the dramatic acceleration that we saw in the internet.”
One of the first private pioneers was Burt Rutan, a mutton-chopped aircraft designer who regarded NASA as a bloated and unimaginative bureaucracy and in 1982 founded a company called Scaled Composites that designed aircraft so innovative that, as Davenport writes, “it was as if his inspiration came not just from the laws of aerodynamics but from Picasso.” One of his ideas was for a manned aircraft that could reach the edge of space and then fold its wings upward to act as a feather allowing the craft to re-enter the earth’s atmosphere, land on a runway, and be reused. It would become his entry in the Ansari X Prize, which offered $10 million for the first private company that could launch a reusable vehicle to space twice within two weeks.
Rutan attracted two billionaire partners. The first was the Microsoft co-founder Paul Allen, who as a schoolboy in Seattle yearned to become an astronaut but, being nearsighted, realized that was impossible so spent his time coding in the school’s computer room with his friend Bill Gates. Rutan’s second partner was the toothy goldilocked Richard Branson, a thrill-addicted serial adventurer and entrepreneur who was as enthusiastic about publicity as Allen was averse to it. Branson’s personal motto for his company, Virgin, was “Screw it, let’s do it,” which was no longer a guiding principle at NASA, and he created Virgin Galactic with the goal of taking tourists into space. “Paul, isn’t this better than the best sex you ever had?” Branson asked Allen during one test flight as the spaceship climbed higher.
In 2004, Rutan’s craft (with a Virgin logo on its tail) flew twice to space and back to win the X Prize. At the celebration, Rutan took a shot at NASA. “I was thinking a little bit about that other space agency, the big guys,” he said. “I think they’re looking at each other now and saying, ‘We’re screwed.’” Branson began selling tickets at prices that started at $200,000 to those who wanted to ride in a similar plane he began building, the launch date of which always seems to be about a year away.
Elon Musk’s love of adventure came partly from his maternal grandfather, an accomplished amateur pilot in South Africa who in 1952 completed a 22,000-mile journey across the globe with no electronic instruments. Musk founded SpaceX in 2002 with the eventual goal of colonizing Mars. “The more Musk studied, the more he realized that there had been very little advancement in rocket technology in the past 40 years,” Davenport writes. “To a self-made Silicon Valley tech entrepreneur, this was stunning.” His company’s mantra was, “Set audacious, nearly impossible goals and don’t get dissuaded.”
Musk’s entrepreneurship had a social purpose. SpaceX, Tesla, his electric car company, and SolarCity, his renewable energy company, Fernholz writes, “were explicitly intended to further human civilization.” Along the way, he developed a cultlike following. When SpaceX managed to launch a space capsule into orbit and dock it at the International Space Station in 2012, something NASA could no longer do on its own, the employees at his headquarters broke into a chant, “We love Elon!”
Bezos was likewise inspired by his own maternal grandfather. Lawrence Preston Gise, an upright but loving naval commander, helped develop the hydrogen bomb during a stint at the Atomic Energy Commission and then retired to his sprawling Texas ranch to enjoy his family — and in particular his insatiably curious little grandson with very big ears, smile and laugh. Bezos’ passion for space began when he was 5 and he watched with his family the launch of Apollo 11, the manned moon mission commanded by Neil Armstrong. “It really was a seminal moment for me,” he said. “I remember watching it on our living room TV, and the excitement of my parents and my grandparents. Little kids can pick up that kind of excitement.”
Bezos spent every summer at his grandfather’s ranch, where he fixed windmills, castrated cattle and geeked out on the tiny county library’s surprisingly large sci-fi collection. His high school valedictorian speech was about space: how to colonize planets, build space hotels and save our fragile planet. “Space, the final frontier, meet me there!” he concluded.
When Bezos founded Blue Origin in 2000, naming it after that pale blue planet where humans originated, he called upon one of his favorite science fiction writers, Neal Stephenson, to be an adviser. They kicked around wildly novel ideas, such as using a bullwhip-like device to propel objects into space. Eventually Bezos focused on reusable rockets. “How is the situation in the year 2000 different from 1960?” Stephenson asked him. “What’s different is computer sensors, cameras, software. Being able to land vertically is the kind of problem that can be addressed by those technologies that existed in 2000 that didn’t exist in 1960.”
Bezos began putting together a huge tract of ranch land in Texas where he could build his reusable rockets in secret. One of the great scenes in Davenport’s book is the description of the helicopter trip Bezos took to find the land, which ended with a terrifying crash. He survived, and it conditioned him to the fact that flying machines sometimes fail. Among Bezos’ many strengths is to be exuberant patiently, to have a long-term horizon, as he has done at Amazon. At his Texas ranch, he has begun construction of a 10,000-year “Clock of the Long Now” designed by the futurist Danny Hillis, which has a century hand that advances every hundred years and a cuckoo that comes out every millennium. In the mission statement for his space company, he wrote, “Blue will pursue this long-term objective patiently, step by step.” As Elon Musk pushed forward with very public fits and starts, Bezos advised his team, “Be the tortoise and not the hare.”
At the end of 2015, within a month of each other, Musk and Bezos both launched rockets that returned safely to earth and were reusable. For the moment, Musk the hare had darted ahead: His powerful Falcon 9 rocket had lifted a payload into orbit, whereas Bezos’ smaller New Shephard craft had merely gone up into the edge of space and returned. But as happens with scrappy entrepreneurial business competitors, in contrast to government bureaucracies, Bezos and Musk were goading each other on. And unlike the race between the tortoise and the hare, they can both triumph — as can, one hopes, Richard Branson and others.
Indeed, even NASA and its big corporate contractor, the United Launch Alliance, a venture between Lockheed Martin and Boeing, can come out winners from competition. As is often the case with the innovation progression, the greatest technological advances come when a symbiosis is reached that combines the resources of a visionary government and the scrappiness of risk-taking entrepreneurs, each spurring the other onward and upward.
[unable to retrieve full-text content]
At the exclusive three-day conference run by Amazon in the California desert, the merely brilliant rub shoulders with the geniuses.
The New Horizons spacecraft got us to Pluto, which it blasted past in 2015. The European Space Agency’s Planck satellite provided some of the farthest-out imagery, the heat map of the cosmos that can show us the incubators of tomorrow’s galaxies. And all of it can be displayed by the kind of brawny gaming computer that can be purchased at Best Buy. It’s a lot of data, and the images occasionally stutter. Hollywood, it isn’t. But it’s still, let’s face it, awesome.
The software that allows the museum to perform this magic is called OpenSpace, and NASA gave the American Museum of Natural History, which houses the planetarium, $6.3 million to develop it. Mr. Emmart, as the museum’s director of astrovisualization — and how great a title is that? — gets to use it.
The software, which is being developed with the help of graduate students from Sweden, high school students in New Jersey and institutions like New York University and the University of Utah, among others, can be run on all kinds of displays, even touch tables and kiosks. Other planetariums and science museums around the world can use it to give their own visitors the chance to fly through the universe. Presentations can be coordinated for live shows across institutions, and the other users can dig into the guts of its open-source software to help refine and develop it.
Credit Yudi Ela for The New York Times
The point of OpenSpace, said Vivian Trakinski, the museum’s director of science visualization, is “for presentation of current science to the public,” exploring data in accessible ways. “And,” she said, drawing out the “aaaa” a bit, “it’s cool.”
The software can use images and data collected in real time, which is what Mr. Emmart wants to show on the return to Earth. “As much as I like to take people to Mars, they say, ‘could we come back to Earth now?’ to see something familiar,” he said.
The globe hangs full in the “sky” above the planetarium, built from fresh satellite images. Zooming in, Mr. Emmert shows the night lights of Beijing and the eerie darkness of power-starved North Korea, versus the shining cities of South Korea, and a zip across major cities of the United States.
For those who can’t pay Richard Branson’s Virgin Galactic a quarter of a million dollars for a quick suborbital trip — a long-promised service that still has not begun flights — “we can show you what it looks like to go to space, and you can go to dinner across the street,” Mr. Emmart said.
OpenSpace is a tool, not an exhibit, so anyone who wants to take a ride through the cosmos should look for events where it will be used — not just at the American Museum of Natural History, where live shows are held at the Hayden Planetarium and LeFrak Theater, but also at sites across the United States, including the Adler Planetarium in Chicago, the California Academy of Sciences in San Francisco, the Denver Museum of Nature & Science, the Houston Museum of Natural Science, and the North Carolina Museum of Natural Sciences in Raleigh.
In New York, the next presentation using OpenSpace will be on March 24, at a program known as Sun Earth Day, with no charge beyond general admission.
While the wow factor of the software is the way that it helps people travel beyond the planet’s pull, the underlying message is that there’s no place like home. This planet, teeming with life and color, is the proof that “our place is here,” Mr. Emmart said. Other places are, literally, alien: “If you go to the Moon, it’s gray; if you go to Mars, it’s reddish.”
“This kind of data visualization makes us appreciate Earth,” he said, “And our need to just manage ourselves with it better. We have no choice.”
Payload will be my midnight cherry Tesla Roadster playing Space Oddity. Destination is Mars orbit. Will be in deep space for a billion years or so if it doesn’t blow up on ascent.
I love the thought of a car drifting apparently endlessly through space and perhaps being discovered by an alien race millions of years in the future
About two weeks ago, a satellite called Iceye-X1 hitched a ride into orbit aboard an Indian rocket. It’s about the size of a suitcase, and has already sent its first picture, constructed out of microwave radar reflections, back to Earth.
“I personally love this image,” said Rafal Modrzewski, the chief executive of Iceye, a Finnish start-up that built and operates the satellite, referring to a scene from the Noatak National Preserve in Alaska. “It’s full of snow, but it’s so much more complex than you think at first.”
The swath of the park visible in the first image is 1.2 gigabytes of data that encompasses an area about 50 miles long by 25 miles wide. It was made using a technology known as synthetic aperture radar, or SAR.
The capability of Iceye-X1 is not by itself groundbreaking. Edward R. Caro, who worked for decades on spaceborne radar instruments at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., said it is roughly comparable in performance to what he and his colleagues put on NASA’s 5,000-pound Seasat satellite early in his career. “It would be analogous what we were flying in 1978,” he said.
But Iceye-X1, which weighs less than 220 pounds, takes advantage of the miniaturization of modern consumer electronics, largely using off-the-shelf components, and the cheaper rides to space now available.
“I can’t praise them enough for what they’ve done,” said Mr. Caro, who provided some consulting to Mr. Modrzewski’s team.
More papers are appearing in Nature, Physical Review Letters and in Science, on topics including nuclear physics and cosmology.
“It’s the greatest fireworks show in the universe,” said David Reitze of the California Institute of Technology and the executive director of the Laser Interferometer Gravitational-Wave Observatory, or LIGO.
Daniel Holz, an astrophysicist at the University of Chicago and a member of the LIGO Scientific Collaboration, a larger group that studies gravitational waves, said, “I can’t think of a similar situation in the field of science in my lifetime, where a single event provides so many staggering insights about our universe.”
The key to the discovery was the detection of gravitational waves, emanating like ripples in a pond vibrating the cosmic fabric, from the distant galaxy. It was a century ago that Albert Einstein predicted that space and time could shake like a bowl of jelly when massive things like black holes moved around. But such waves were finally confirmed only in 2016, when LIGO recorded the sound of two giant black holes colliding, causing a sensation that eventually led this month to a Nobel Prize.
Credit National Optical Astronomy Observatory
For the researchers, this is in some ways an even bigger bonanza than the original discovery. This is the first time they have discovered anything that regular astronomers could see and study. All of LIGO’s previous discoveries have involved colliding black holes, which are composed of empty tortured space-time — there is nothing for the eye or the telescope to see.
But neutron stars are full of stuff, matter packed at the density of Mount Everest in a teaspoon. When neutron stars slam together, all kinds of things burst out: gamma rays, X-rays, radio waves. Something for everyone who has a window on the sky.
“Joy for all,” said David Shoemaker, a physicist at the Massachusetts Institute of Technology who is the spokesman for the LIGO Scientific Collaboration.
This is the story of a gold rush in the sky.
It began on the morning of Aug. 17, Eastern time. Dr. Shoemaker was on a Skype call when alarms went off. One of the LIGO antennas, in Hanford, Wash., had recorded an auspicious signal and sent out an automatic alert. Twin antennas, in Washington and Livingston, Louisiana, monitor the distance between a pair of mirrors to detect the submicroscopic stretching and squeezing of space caused by a passing gravitational wave. Transformed into sound, the Hanford signal was a long 100-second chirp, that ended in a sudden whoop to 1000 cycles per second, two octaves above middle C. Such a high frequency indicated that whatever was zooming around was lighter than a black hole.
Welcome to the place of no return — a region in space where the gravitational pull is so strong that not even light can escape it. This is a black hole.
Checking the data from Livingston to find out why it had not also phoned in an alert, Dr. Shoemaker and his colleagues found a big glitch partly obscuring the same chirp.
Meanwhile, the Fermi Gamma-Ray Space Telescope, which orbits Earth looking at the highest-energy radiation in the universe, recorded a brief flash of gamma rays just two seconds after the LIGO chirp. Fermi sent out its own alert. The gamma-ray burst lasted about two seconds, which put it in a category of short gamma ray bursts, which astronomers suspect are neutron stars colliding.
“When we saw that,” Dr. Shoemaker said, “the adrenaline hit.”
Dr. Kalogera, who was in Utah hiking and getting ready for August’s total solar eclipse when she got the alarm, recalled thinking: “Oh my God, this is it. This 50-year-old mystery, the holy grail, is solved.”
Together the two signals told a tale of a pair of neutron stars spiraling around each other like the blades of a kitchen blender.
Credit Alex Wroblewski for The New York Times
Luckily the European Virgo antenna had joined the gravitational wave network only two weeks before, and it also showed a faint chirp at the same time. The fact that it was so weak allowed the group to localize the signal to a small region of the sky in the Hydra constellation that was in Virgo’s blind spot.
The hunt was on. By then Hydra was setting in the southern sky. It would be 11 hours before astronomers in Chile could take up the chase.
One of them was Ryan Foley, who was working with a team on the Swope telescope run by the Carnegie Institution on Cerro Las Campanas in Chile. His team made a list of the biggest galaxies in that region and set off to photograph them all systematically.
The fireball showed up in the ninth galaxy photographed, as a new bluish pinprick of light in the outer regions of NGC 4993, a swirl of stars about 130 million light-years from here. “These are the first optical photons from a kilonova humankind has ever collected,” Dr. Foley said.
Graphic: What Is General Relativity?
Within 10 minutes, another group of astronomers, led by Marcelle Soares-Santos of Brandeis University and using the Dark Energy Camera, which could photograph large parts of the sky with a telescope at the nearby Cerro Tololo Interamerican Observatory, had also spotted the same speck of light.
Emails went flying about in the Chilean night.
When it was first identified, the fireball of 8,000-degree gas was about the size of Neptune’s orbit and radiating about 200 million times as much energy as the sun.
Nine days later, the orbiting Chandra X-ray Observatory detected X-rays coming from the location of the burst, and a week after that, the Very Large Array in New Mexico recorded radio emissions. By then the fireball faded from blue to red.
From all this, scientists have begun patching together a tentative story of what happened in the NGC 4993 galaxy.
“It’s actually surprising how well we were able to anticipate what we’re seeing,” said Brian David Metzger, a theorist at Columbia University who coined the term kilonova back in 2010.
As they tell it, the merging objects were probably survivors of stars that had been orbiting each other and had each puffed up and then died in the supernova explosions in which massive stars end their luminous lives some 11 billion years ago, according to an analysis by Dr. Kalogera. Making reasonable assumptions about their spins, these neutron stars were about 1.1 and 1.6 times as massive as the sun, smack in the known range of neutron stars.
As they approached each other swirling a thousand times a second, tidal forces bulged their surfaces outward. Quite a bit of what Dr. Metzger called “neutron star guts” were ejected and formed a fat doughnut around the merging stars.
At the moment they touched , a shock wave squeezed more material out of their polar regions, but the doughnut and extreme magnetic fields confined the material into an ultra-high-speed jet emitting a blitzkrieg of radiation, the gamma rays.