We are, as earthlings, lucky to be able to witness the spellbinding beauty of the Auroras. While it is much easier for us to see this fascinating phenomena from our Blue planet, Northern Lights are by no means an exclusively earthly phenomena and can be seen from several other planets.
The phenomena of Aurora Borealis is, on the planet Earth, a result of high-energy solar particles crashing into our atmosphere and reacting to its own, weaker particles. The reason why this phenomena can happen in the first place is because of the Earth’s powerful magnetic field which spontaneously deflects the energy-rich solar winds while allowing some of those to reach the planet’s poles. While Earth is unique in many aspects, it is only one of the numerous planets that have their own magnetic sphere. (1)
[aesop_image imgwidth=”100%” img=”http://www.bivrost.com/wp-content/uploads/2015/08/DSC4078.jpg” align=”center” lightbox=”off” caption=”On Earth, Northern Lights appear most often Green and Red. On other planets, they behave somewhat differently.” captionposition=”center”]
Saturn, the famously ringed planet named after the ancient Roman God of the sky, does experience Auroras as well! The main difference between Saturn and Northern Lights on Earth is the gas that is involved in the formation of the Aurora. While on Earth, Oxygen and Nitrogen are the most common gases, creating respectively green and red Lights, Saturn’s atmosphere is mainly made of Hydrogen, which creates blueish Auroras. Hydrogen is also a much lighter gas than either Nitrogen or Oxygen, and as a result, Saturn’s Auroras can reach heights of up to 1200 kilometers, as opposed to maximum 500 kilometers for Earth’s! (2)
[aesop_video width=”100%” align=”center” src=”youtube” id=”LgwkLvftRZI” loop=”on” autoplay=”on” controls=”on” viewstart=”on” viewend=”on”]
Similar ´Galactic´ Auroras can also be experienced on Jupiter (pictured in the beginning of the article) and Uranus. Uranus is in fact the most distant planet in our Solar System that experiences Auroras. While Saturn is ´only´ 1,5 billion kilometers away from the Sun, Uranus lays twice as far from our galactic star! As a result, the Solar Winds take much longer to reach Uranus than, for example, the Earth. When a solar eruption occurs, we humans can expect to see Northern Lights within 48 hours of the original blast in most cases. The non-existent population of Uranus has it much worse: it takes about two full months for the solar particles to get to Uranus, and when this happens, the Auroras last for only a few minutes, as opposed to several hours on Earth! (3)
[aesop_image imgwidth=”100%” img=”http://www.bivrost.com/wp-content/uploads/2015/08/Blue-e1439552736511.jpg” align=”center” lightbox=”on” caption=”On Uranus, the Blue planet, even the Auroras are blue!” captionposition=”center”]
And that’s not all! Who said that Auroras were restricted to our Solar System? As recently as last month, scientists have discovered that a Brown Dwarf (a celestial object halfway between a planet and a star) from the distant Lyra constellation experienced Northern Lights as well! The most fascinating thing about it? The scientists have theorized that the brown dwarf (named LSR J1835 by the way) may ´auto-generate´ Northern Lights using its own high-energy particles! Auroras are indeed fascinating when they appear even in the farthest corners of our Galaxy and the Universe. (4)
- (1) Davis, Neil. (1992). The Aurora Watcher Handbook. Fairbanks. University of Alaska Press. (163 – 169).
- (2) Article on the NASA website.
- (3) Article on space.com.
- (4) Article on the BBC.
- (I) Picture of Auroras on Jupiter Ⓒ ESA/Hubble
- (II) Powerful Northern Lights over Iceland in February 2014. Ⓒ Lyonel Perabo
- (III) Video of Northern Lights on Saturn Ⓒ ESA/Hubble
- (IV) Auroras on Uranus. Ⓒ NASA, ESA, and L. Lamy (Observatory of Paris, CNRS, CNES)