Do you ever find yourself craving to know what will become of us beyond the mortal coil? What will happen after the lights go out and all worldly attachments disintegrate? Is it possible to continue to exist, unmoored out there in the ether?
According to recent scientific research published today in the journal Nature, the answer is an unequivocal yes. Astronomers reported observing a cosmic situation that may anticipate what our solar system will look like after the sun fizzles out. About 6,500 light-years away, a Jupiter-size planet orbits a white dwarf, the remnant of a dead star.
More tantalizing still, the situation may offer insights into the nature of extraterrestrial life in white dwarf systems.
An artist’s rendering of the sun collapsing into a white dwarf in five or so billion years. Photo: Adam Makarenko/W. M. Keck Observatory
A new planet, and its white dwarf star
The gas giant orbits at about the same distance from its star as Jupiter does from the sun. It appears to have remained intact despite the supernova that preceded the white dwarf. Known as MOA-2010-BLG-477Lb, it’s unique in that it retained its composition through the explosion. Most known objects orbiting white dwarfs are simply debris.
Joshua Blackman, a post-doctoral researcher at the University of Tasmania and lead author of the study, explained the discovery to The New York Times via email.
“While there is quite a lot of evidence of rocky planetary debris orbiting around white dwarfs, we have very few data points of intact planets,” he said. “The fate of our solar system is likely to be similar to MOA-2010-BLG-477Lb. The sun will become a white dwarf, the inner planets will be engulfed, and the wider-orbit planets like Jupiter and Saturn will survive.”
Astronomers first spotted this unusual pair from the Keck Observatory. They noticed it through an effect called microlensing, in which an object’s gravitational field warps light. The team found the planet first, then spent years searching for the star that it was orbiting. Finally, they concluded that it was too faint to observe and must be a white dwarf.
The W.M. Keck Observatory, in Hawaii. Photo: Tim Rawle
Planets can survive supernovas, but can life?
MOA-2010-BLG-477Lb is not the first gas giant found orbiting a dead star, but most of the others orbit their stars very closely. Because MOA-2010-BLG-477Lb orbits its white dwarf, it is the one that most closely resembles the probable outcome of our solar system. It could also contain insights into ongoing life in the system, if such a thing exists.
According to Lisa Kaltenegger, the director of the Carl Sagan Institute at Cornell University, life-sustaining solar systems could produce new organisms during the fallout of a supernova event.
“I find the study exciting because it adds to the growing evidence that planets can survive the death of their star, which leads to intriguing questions about the future of the cosmos,” Dr. Kaltenegger told the Times. “If planets can survive the death of their stars, can life as well?”
A Supernova in Galaxy M82, as captured by the Hubble telescope. Photo: NASA
The possibility might be more feasible than one would think. The life cycle of a star produces significant heat fluctuations on the planets orbiting it. As a result, the possibility of life on a planet can vary significantly over time.
“If humanity is somehow still around in five billion years,” Dr. Blackman speculated, “we would probably have a better chance of surviving the sun’s red giant phase on a moon of Jupiter than on Earth.”
Possibly, planets like MOA-2010-BLG-477Lb constitute insights into our future — and could lead to new information about extraterrestrial life. The answers could become more evident as scientists leverage advanced observatories to find more intact planets orbiting white dwarfs.
“This is the first detection of a planet orbiting a white dwarf made using the microlensing technique,” Dr. Blackman concluded, “but almost certainly not the last.”
