Planets the size of Jupiter orbit a type of star called a white dwarf and provide an idea of what our solar system would look like if the sun burned out. Or: If humanity still exists in five billion years, we might have a better chance of surviving the red giant phase of the Sun on Jupiter’s moon than Earth.
MOA-2010-BLG-477Lb Discovery Not only does it offer a glimpse into our cosmic future, it also increases the likelihood that any life on the “surviving world” could survive the death of its stars. It is likely that the fate of our solar system will be similar to that of MOA-2010-BLG-477Lb. The sun will become a white dwarf, the inner planets will engulf and the planets with larger orbits like Jupiter and Saturn will survive.
The planet was first seen due to the distorting effect of light from the gravitational field, a phenomenon known as microlensing. After years of searching for its host star with the Keck II telescope in Hawaii, it was determined that it orbits a white dwarf that is too faint to be observed directly.
Astronomers using a different method last year reported seeing another healthy Jupiter-like planet, known as WD 1856 b, also orbiting a white dwarf. But MOA-2010-BLG-477Lb orbits its white dwarf at about three times the distance between Earth and the Sun, making it the first known planet to orbit a Jupiter-like white dwarf. On the other hand, WD 1856 b orbits its white dwarf every 1.4 days, indicating that it migrated to its current position after the death of its star, although the exact mechanism of the flight is still being investigated.
Can life also be lived?
This new discovery could provide insight into the search for extraterrestrial life and potential habitation for white dwarf systems. Lisa Kaltenegger, director of the Carl Sagan Institute, has suggested that some galaxies containing life may undergo a “second formation,” in which new objects appear in the regenerated remnants of white dwarf systems.
Or: If a planet can survive the death of its star, can life on that planet too? Dying stars emit harmful radiation as they grow into so-called red giants, creating disturbances in their systems that could destroy life. But there are some speculative scenarios in which the habitability of the planets could be maintained in white dwarf systems.
There are a lot of things that have to go well. It could be a distant planet from a red giant star that then moves inward after the star becomes a white dwarf and holds enough water to become a habitable place when the star turns into a white dwarf.
In five billion years we will be better off in Europe
Because white dwarfs are small and dim, such planets must be in very close and very short orbits for liquid water to exist. However, if life emerged on a world like Jupiter’s moon Europa, which could have a subsurface ocean heated by Jupiter’s tidal forces, it would likely also live at greater distances than a white dwarf.
Or: If humanity still exists in five billion years, we might have a better chance of surviving the red giant phase of the Sun on Jupiter’s moon than Earth.
While the existence of life around white dwarfs is still a matter of speculation, the next generation of observatories, Like the James Webb Space Telescope, can help provide a specific answer to this question. When healthier planets orbiting white dwarfs are observed, scientists will have a clearer picture of life and the afterlife of this mysterious system of extinct stars. This is the first discovery of a planet orbiting a white dwarf, but it certainly won’t be the last.
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