Working away in the university’s quiet Physics/Astronomy building, these scientists are teaching computers how to sift through massive amounts of data to identify asteroids on a collision course with Earth.
Together with 60 colleagues at six other universities, the 20 UW scientists are part of a massive new data project to catalog space itself, using the largest digital camera ever made.
Five years from now, a sky-scanning telescope under construction in Chile will begin photographing the night sky with a 3,200-megapixel camera. The telescope will have the power to peer into the solar system and beyond, and track things we have never been able to track before — including asteroids, the rubble left behind during the formation of the solar system.
When it is up and running, the Large Synoptic Survey Telescope (LSST) will produce 20 terabytes of images every night, and will be able to photograph half the night sky every three days, said Andrew Connolly, one of the UW astronomers working on the project.
It will replace the Sloan Digital Sky Survey, which dates back to 1998, and which was only able to cover one-eighth the sky over 10 years. The LSST’s mission is different from NASA’s Hubble Space Telescope, which sends back detailed photos of specific regions of space, but does not take vast surveys of everything in the sky.
“It is going to be a nightly deluge of data,” said Ed Lu, a former NASA astronaut who is now executive director of the new B612 Asteroid Institute, which is dedicated to protecting Earth from asteroid strikes. “This is a cross between computer science and astronomy.”
The Seattle region’s reputation as a big-data powerhouse is one of the reasons UW scientists are playing such a key role in the work, said Lu, who is based in Silicon Valley. Another reason: The Chile telescope was funded in its early stages by a $30 million grant from Microsoft co-founder Bill Gates, and from the Charles and Lisa Simonyi Fund (Charles Simonyi, a former Microsoft executive, has traveled into space twice as a space tourist).
If an asteroid strike is the stuff of your nightmares, rest assured: No known asteroids are currently on a collision course with Earth. And if they were, there are some ways to deflect them, or even get out of their way.
The danger asteroids pose became clear in 2013, when more than 1,000 people were reportedly injured after a meteor exploded near the Russian town of Chelyabinsk. (Meteorites are closely related to asteroids.)
And 66 million years ago, many scientists believe, an asteroid the size of a mountain smashed into Mexico’s Yucatán Peninsula, dramatically changing Earth’s environment and wiping out the dinosaurs.
Scientists have already plotted the orbits of more than 700,000 known asteroids in the solar system, said Željko Ivezic, a UW astronomy professor and project scientist for LSST. The LSST will help astronomers identify an estimated 5 million more.
That’s why teaching a computer to identify asteroids is such vital work.
“It’s like playing connect-the-dots where all of the dots are sitting on top of one another, and you have to separate them out,” said the UW’s Connolly. “That’s why you have to come in with a computer, and that’s why computational techniques become so important.”
The B612 Asteroid Institute will take the information gleaned from the data and decide if any of the asteroids pose a risk to the planet. If they do, NASA, the European Space Agency and the world’s nations will have to decide what to do.
Lu, the astronaut, co-founded the B612 Foundation 16 years ago to raise awareness of the potentially devastating impacts of an asteroid strike. He was inspired to do something after his three missions to space, including six months on the International Space Station.
When he looked down at Earth, he often saw shooting stars — small meteoroids — burning up in the atmosphere. (“I used to love watching them,” he said.) And he looked out at the moon, and could see its surface pockmarked with craters caused by asteroid strikes.
Those visible signs of the dangers from space, he said, made him “realize, at some point, we have to do something.”
The UW’s Ivezic said that if we knew an asteroid was on a collision course with Earth in days or weeks, its point of impact could be calculated to within about 100 miles, and the area could be evacuated.
If we had a longer warning — years or decades — it’s possible to nudge an asteroid out of its orbit. The simplest way would be to run into it with a small spacecraft traveling at high speed, Lu said. A spacecraft could also “tow” an asteroid by flying near it, changing its orbit. A last resort, he said, would be to hit it with a nuclear weapon.
“But none of this is any use if you don’t find and track them first,” he said.
Scientists hope that after scanning the heavens for dangerous asteroids, “we’ll find out that for the next few centuries there is no danger, so we don’t have to involve NASA and spacecraft and the president,” Ivezic said.
“Let our grandchildren deal with it — they’ll have better technology.”
Meet DIRAC
The LSST is a public-private venture that gets money from the National Science Foundation and U.S. Department of Energy. It will provide a wealth of data beyond asteroids.To make good use of that information, the UW this year created an institute, the Data Intensive Research in Astrophysics and Cosmology Center (DIRAC), funded by a donation from the Simonyis. The acronym is also a nod to Paul Dirac, the English theoretical physicist who predicted the existence of antimatter.
The center’s 25 to 30 researchers and faculty will be charged with thinking about the kind of science that can be done with the LSST data, said Connolly, its director. For example, the asteroid census might help scientists figure out when, where and how the solar system was formed, whether planets exist beyond Neptune or why they are distributed the way they are. The observations may also tell more about how fast the universe is accelerating, and unravel the mysteries of dark energy and dark matter.
DIRAC will also help “citizen scientists” — amateur astronomers, students, or high-school students — use the LSST information.
LSST’s computers will send out a stream of nightly alerts as they detect changes in space. The alerts will be freely available to anyone, making it a boon for scientists and amateurs alike. An amateur astronomer could train a backyard telescope on an area where the LSST has spotted something interesting, for example, and make his or her own observations.
Both Connolly and Ivezic say processing huge data sets is a bit like what Amazon.com does, with its massive catalog of goods that must be delivered to specific customers in short periods. In other words, it’s a huge data-set problem — and Seattle has a wealth of knowledge in dealing with big data.
“It mixes computing, new cutting-edge science, statistics, the engagement of the community, the understanding of the formation of our universe,” Connolly said. “It’s a great fit for the Pacific Northwest.”
©2017 The Seattle Times Distributed by Tribune Content Agency, LLC.
