We often get asked a great question. Is the Earth the only planet that has auroras? We put that question to our resident astronomer, Matt.
No, we are absolutely not the only planet to see aurora, similar atmospheric displays have been observed on all planets except Mercury due to its close proximity to the Sun.
Auroras occur in the atmosphere of the Earth because we have a strong magnetic field and the interaction between magnetically charged particles on the solar wind and gaseous molecules in our atmosphere. We see auroras on planets, Venus, Mars, Jupiter, Saturn, Uranus and Neptune from pretty much the same processes. The magnetic and atmospheric dynamics of all these planets are different so some have stronger auroras than others.
Jupiter's auroras are particularly striking and are much larger and more intense than those on Earth. They are caused by charged particles from the planet's magnetosphere colliding with the atmosphere near the poles. Jupiter’s magnetic field is 20,000 times stronger than the Earth’s.
Ultraviolet Aurora on Jupiter overlayed onto Hubble – Credit NASA
Saturn's auroras are also caused by interactions between charged particles and the planet's atmosphere, but they are less intense than those on Jupiter due to it having a weaker magnetic field.
Ultraviolet Aurora on Saturn overlayed onto Hubble – Credit NASA
Uranus and Neptune have weaker auroras than Jupiter and Saturn, and their auroras are thought to be caused by interactions between the planet's magnetic field and the solar wind. These planets are 1.8 and 2.8 billion miles from the Sun respectively, so it comes as no surprise that auroras here are weak and infrequent.
Aurora on Uranus – Credit NASA/ESA
Excitingly, auroras on Mars have only recently been photographed for the first time by the NASA MAVEN mission In 2018. Mars' auroras are thought to be caused by interactions between the solar wind and the localized magnetic fields on the planet's surface. Unlike Earth's auroras, which occur primarily at the polar regions, Mars' auroras can occur at lower latitudes, sometimes as far south as 30 degrees.
Aurora on Mars – Credit EMM/EMUS
So, auroras in some forms have been observed on 7 out of the 8 planets in our solar system. What makes ours special is we can observe ours with the naked eye and it’s much easier and safer to travel to our aurora zone than it is to Jupiter’s or Saturn’s.