ANYBODY OUT THERE?
Here's Looking at You, Universe
I dropped by NASA headquarters last Monday to hear about the relatively nearby and extremely massive star that might explode at any moment. Remember the name: Eta Carinae. Sounds like an Italian opera singer, or maybe a snazzy little sports car. It's a monster of a star -- something like 120 times the mass of the sun, and roiling, heaving, spewing out gobs of star stuff in what may be the prelude to a cataclysmic bang, a supernova unlike any seen before.
If it blows, you might be able to read a book by its radiance at night -- unless it fires a narrow beam of gamma rays right at us, in which case all bets are off. One astrophysicist on hand said, "It would probably destroy all the ozone in the atmosphere." Similar to what we tried to do ourselves, before we banned those nasty chlorofluorocarbons. Eta Carinae would be like a giant can of 1950s hairspray. Not a pleasant picture.
This new look at our friendly neighborhood Death Star follows the observation, last September, of a much more distant supernova, which scientists have given the lovely name of SN 2006gy. This was a gargantuan star much like Eta Carinae. The orthodoxy had been that "Eta Car" would have to go through a gradual process of shedding its "hydrogen envelope" before it would explode. But SN 2006gy didn't bother with that. And while most stars that explode leave behind a solid core of material, this star annihilated itself. Nothing left but fireworks.
The bulletins from space arrive almost daily. More than 200 "extrasolar" planets, far from our own solar system, have been found over the past dozen years. Most are "hot Jupiters" -- gas giants in tight, scorching orbits. But just last month, astronomers said they'd found, mixed with the light of a nearby star, the signature of a planet that might be rocky like the Earth and orbiting at a distance at which liquid water and life could be possible. And last week, astronomers at Harvard said they'd made a rough map of another extrasolar planet that they believe has a big red spot and is buffeted by powerful, hot winds.
But behind all this stellar news is another headline: We are in the golden age of telescopes. We know what we know about SN 2006gy and Eta Carinae and all the rest because computer-aided telescopes, both on the ground and in space, have checked them out in multiple wavelengths, from the visible to the X-ray. And we're seeing a more interesting, chaotic and preposterously vast universe than anything Galileo could have imagined.
Space-based astronomy is a part of our space program that really works. Space science has been a great investment at a time when we've found so many ridiculous things upon which to waste billions of taxpayer dollars. But the NASA science budget, currently $5.5 billion, has leveled off after years of growth, and some major telescope projects have already been put on the far back burner. The budget is likely to remain tight as the agency follows President Bush's "Vision for Space Exploration": to send astronauts back to the moon. It's a goal that might make some long-term sense if we're going to become citizens of the entire solar system, though it remains to be seen whether the public really wants to pay for astronauts to land on the moon 'round about the 50th anniversary of the first time they did so.
In coming years, policymakers will need to remember that telescopes give a big bang for the buck. Each new instrument changes our view of the universe. Go back to Galileo: His great revelation was not merely that Jupiter had some little satellites orbiting it, or that Venus had phases like those of the moon, or that the moon had features that looked like mountains, but that all of these things in the sky were worlds, that they were in the same general category of object as the Earth. Science has steadily removed us from our privileged position in the cosmic scheme of things. Are we really alone? Astronomy may give us the answer.
Last week, a remarkable object materialized on the Mall near the National Air and Space Museum. It was a mock-up of the James Webb Space Telescope, which is scheduled to be launched in 2013.
The Webb looks ungainly. It features a 20-foot-diameter honeycomb-like mirror jutting above five layered sun shields that cover an area the size of a tennis court. To squeeze into the rocket at launch time, it has to be folded up. Then it'll have to unfold when it reaches its destination a million miles from Earth -- more than four times the distance to the moon.
What if it doesn't unfold? Isn't that too far away to fix? Ed Weiler, head of NASA's Goddard Space Flight Center, revealed the surprising answer at a news conference next to the mock-up: Astronauts might actually make the million-mile hike to service the telescope. Perhaps that's the future of the space program: Astronauts going into outer space not to plant flags and leave footprints and hit golf balls in low gravity and whatnot, but to service the expensive hardware that a space-faring and curious civilization requires.
We look into space not because a supernova may zap us, but because it's like a huge message written in code, daring us to read it. Why are we here? Why does the universe exist? What else -- who else -- is out there? These are simple questions, but they're not easily answered. Still, the information is there, inscribed in electromagnetic radiation that does us the great favor of crossing the universe and landing in the light buckets we call telescopes.
Light moves at tremendous speed, but it is still a finite speed, and thus when we look into space we are seeing the past. Telescopes are time machines. The deeper we look, the farther back in time we see. The Hubble Space Telescope can see all the way back to about one billion years after the origin of the universe. The Webb will look even farther.