Astronomers have provided new insights into the ultimate fate of the Earth and the solar system as the sun approaches the end of its life in about five billion years. Researchers from the University of St Andrews used the James Webb Space Telescope to observe a Jupiter-sized exoplanet orbiting a white dwarf star, offering a rare glimpse into the future evolution of planetary systems after their host stars die.

The study focused on WD 1856 b, an exoplanet transiting a white dwarf, which is the remaining core of a star that has shed its outer layers. This observation allowed scientists to explore conditions around a "dead" star, essentially acting as a cosmic "time machine" to predict what may happen to planets once their sun expands and eventually fades.

According to the research published in the journal Nature, the sun will exit its main sequence phase when it runs out of hydrogen fuel in its core. This will cause it to expand dramatically into a red giant, growing to more than 100 times its current size. During this phase, the sun will lose much of its mass by shedding its outer layers before contracting into a white dwarf.

The findings confirm that the inner planets—Mercury and Venus—will be engulfed and destroyed during the sun's red giant phase. Earth may also face destruction, although some uncertainty remains regarding its precise fate. The study’s lead author, Dr. Ryan MacDonald of the University of St Andrews, emphasized the significance of the observations, stating that astronomers typically look back in time with telescopes but, in this case, were able to glimpse possible future scenarios for outer planets orbiting remnants of sun-like stars.

This research adds to growing knowledge about stellar evolution and planetary survival, helping scientists better understand how planetary systems like our own may transform billions of years from now.