Earth Is Drifting Away From the Sun Into the Darkness of Space
The potential of eternal darkness is as grim and foreboding as it sounds, and news that the Sun's grip on our planet is loosening might suggest that we're headed there sooner rather than later.
The Sun sheds incrementally small amounts of its mass as it ages in the form of charged particles, turning its hydrogen atoms into helium and thus weakening its gravitational pull on planets such as ours. Now researchers have calculated the precise rate of this shift, presenting their findings in a study published last Thursday in the Nature Communications journal.
"The NASA MESSENGER mission explored the innermost planet of the solar system and obtained a rich data set of range measurements for the determination of Mercury's ephemeris," reads the study's abstract. "Here we use these precise data collected over seven years to estimate parameters related to general relativity and the evolution of the Sun."
Mercury is used as a test planet for these experiments because of its sensitivity to the Sun's activity. After crunching the numbers the researchers found that we can afford to drift about ten millimeters a year, as our planet is about 93 million miles from the Sun. This means that the Earth's orbit will likely shift about 150,000 kilometers before the Sun dies—only about .1 percent of our distance away from it.
"We're addressing long-standing and very important questions both in fundamental physics and solar science by using a planetary-science approach," Erwan Mazarico, coauthor of the published paper and a geophysicist at NASA's Goddard Space Flight Center, said in a statement. "By coming at these problems from a different perspective, we can gain more confidence in the numbers, and we can learn more about the interplay between the Sun and the planets."
"The study demonstrates how making measurements of planetary orbit changes throughout the solar system opens the possibility of future discoveries about the nature of the Sun and planets, and indeed, about the basic workings of the universe," added co-author Maria Zuber, vice president for research at MIT.
There is still much about the Sun that we simply don't know. Last fall's total solar eclipse caused weird changes to the Sun's magnetic field called coronal loops.
That same magnetic field also destroyed a solar eruption on its surface, an eruption similar to that of solar flares that shoots energy and debris out from the sun when it peaks. While flares let out x-rays, the solar eruption would have let out plasma had it not been destroyed by the Sun's magnetic field.