Earth Is Safe. The Planets (And Pluto) Won’t Change Orbits And Cause Havoc For At Least 100,000 Years, Say Scientists

Need some good news? The orbits of the eight main planets—and Pluto—will mostly remain where they are for the next 100,000 years.

That’s important because we know that the planets in the solar system moved around a lot in the past—and when they move they cause untold havoc.

The “Grand Tack” model suggests that Jupiter spent some time in the inner solar system, pulled inwards on swirls of gas, but kept from creeping closer to the Sun by the gravity of Saturn. Both of the planets then drifted farther out.

That’s a comforting model for astronomers because when they look at distant star system they often often see Jupiter-sized planets close to their star. These “hot Jupiters” often orbit closer to their star than Mercury does to the Sun.

Jupiter is now 5.2 astronomical units (Earth-Sun distances, expressed as au) and Saturn 7 au—and that’s where they will remain for the time being.

The paper, published as pre-print, looked at the masses and orbits of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. The computer code performed its calculations with 6,290,000 steps, with each step representing about six days—so 100,000 years in total.

It concluded that the orbits of each planet will vary within or less than 1% over 100,000 years, but the news gets even better. With a super-computer to help the researchers reckon they could prove that the eight planets will remain stable for at least a million years, and probably a lot longer.

The main unknown is asteroids, dwarf planets and other small bodies across the solar system.

Wishing you clear skies and wide eyes.