The Southern Ring Nebula looks as though a bomb dropped into an ocean, tsunami waves surging away, into the darkness. Cosmic light, presented in the colors of a lapis stone, seems to fill a gaping crater in space.
NASA scientists, giddy to reveal the new image from the James Webb Space Telescope at an event earlier this week, beamed with delight. Here it is, they said: a dying star. It had sloughed its outermost layers, a seafoam of molecular hydrogen.
But for fatalists the world over, gazing into this planetary nebula some 2,500 light-years away may not have inspired celebratory feelings — rather, a foreboding of what's to come. Perhaps Joel Achenbach, a Washington Post reporter, felt it, too.
"Are we sad about the star dying?" he asked the experts during a broadcasted news conference on Tuesday.
Chuckles followed. But it's easy to internalize the story of the Southern Ring Nebula(opens in a new tab) as the sun's own destiny — written in, well, the stars.
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For the past six months since Webb launched into space, NASA has promised this telescope would crack the universe wide open with its penetrating vision and science capabilities, bringing humankind in on secrets of how it all began. Astrophysicists who saw sneak previews of the first images told reporters they had chills or an "ugly cry"(opens in a new tab) as some of the very first galaxies to exist popped into focus. Yet perhaps just as compelling as the origin story is the answer to how this all ends.
The dying star wheezes. Puff… Puff… Puff… each successive cloud ring withers the star to its core, a white dwarf(opens in a new tab) of carbon and oxygen. It will grow cold. Then the light goes out.
Unlike giant stars that explode into a supernova(opens in a new tab) and collapse into a black hole, a medium star like the one creating a planetary nebula runs out of nuclear fuel and suffers a more tortured end.
"It's not just any star — it's a star that is much like the sun," said Klaus Pontoppidan, an astronomer at the Space Telescope Science Institute in Baltimore, "at least like the sun will be in 5 billion years when the sun dies."
"It's not just any star — it's a star that is much like the sun, at least like the sun will be in 5 billion years when the sun dies."
The photo, among the first released from the $10 billion observatory in space, appears as if scientists happened to point the telescope at just the right moment to catch a cataclysmic event. And indeed, the 10,000-or-so years of this phase are but a moment relative to the 13.8 billion years of the universe.
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Finding it, though, wasn't serendipity. Astronomers have known about the Southern Ring Nebula, aka NGC 3132(opens in a new tab), since before pasteurized milk. As scientific knowledge advanced, they came to better understand planetary nebulas(opens in a new tab) (a confusing misnomer because they don't have anything to do with planets), as the death throes of medium-sized stars. Scientists have discovered a few thousand of them in the Milky Way.
The late British astronomer David S. Evans even suspected in 1968(opens in a new tab) that at this nebula's core were actually two stars, though one would have to be concealed by gas and dust. The revelation of Webb's photo, 54 years later, is the ability to see the dimmer star — the true source of the nebula — in full detail with the telescope's mid-infrared instrument(opens in a new tab).
NASA scientists marveled at the intricate detail on display. On the outer edges are bright, straight pins of light. Those are spotlights from the central stars, like those Biblical representations of God, sunbeams pouring through parting clouds after a storm.
The sun is halfway to the Southern Ring's fate, said Paul Sutter, research professor at Stony Brook University and author of How to Die in Space.
Researchers have estimated the age of the sun by observing all sorts of stars at different intervals. Think of it like taking snapshots of people at different phases of life, Sutter says: babies being born, Little League games, weddings, sickness, and then death. Those observations are combined with knowledge of the physics going on in the sun's core.
"It turns out our sun is middle-aged. It's going through a midlife crisis right now. It just bought a Corvette and is worried about its retirement fund. It's right there."
"It turns out our sun is middle-aged," Sutter said. "It's going through a midlife crisis right now. It just bought a Corvette and is worried about its retirement fund. It's right there."
In astronomy, looking farther translates into observing the past because light and other forms of radiation must travel incredible distances to reach us. It's conceivable that the Southern Ring light show is already over, its white dwarf no longer able to illuminate it. But in all likelihood, it's probably ongoing, albeit fainter, says Rodolfo Montez, who studies dying sunlike stars at the Center for Astrophysics Harvard and Smithsonian(opens in a new tab).
Through the Hubble Space Telescope(opens in a new tab), Webb's visible-light predecessor, planetary nebula experts have found so many irregular, non-spherical shapes among these celestial structures, influenced by a second central star, that they wonder if having the extra star is actually a key ingredient for their creation.
"It's called a binary hypothesis, which would suggest that [only] stars in binary systems make planetary nebulae," Montez said. "But then we're not clear what single stars like our sun would do in that framework."
Just another mystery for Webb to unravel.
The ripples shed from the dying star in the Southern Ring Nebula carry metals through space like spores. Those last gasps will forge molecules and germinate new objects in the cosmos. Stars are element factories(opens in a new tab), astrophysicists say: They make carbon, for instance, the same chemical on which humans and much of life on Earth are based.
Are we sad about the star dying?
Pontoppidan gave an indirect response. His answer was based on science, but it sounded almost spiritual.
"This is the end for the star," he said. "But it's the beginning for other stars and for other planetary systems."
