Jupiter is the first of the gas giants as one moves away from the sun and is the largest planet in our solar system. In fact, Jupiter is so larger that it has more mass than all of the other planets combined. A thousand Earths could “fit” into one Jupiter (Cosmos by Carl Sagan; 1980). HPL called the gas giants the “superior” planets while he called the small, rocky worlds closer to the sun the “inferior” planets (Collected Essays, Volume 3: Science H.P. Lovecraft; edited by S.T. Joshi 2005).
Jupiter is one of the brightest planets in the sky, second only to Venus. A “Jovian” day is 10 hours long and a Jovian year is 12 Earth years. As stated in a previous article the Earth is 1.0 astronomical unit (AU) away from the sun, while Mars is 1.52 AUs from the sun. In contrast, Jupiter is 5.2 AUs away from the sun (Cosmology: The Science of the Universe by Edward R. Harrison; 1981).
The moon, Venus, Mercury and Jupiter in the sky on the 4th of January 2009. Note Venus is the brightest planet followed by Jupiter (from http://www.jp.man.ac.uk).
In HPL’s day, it was recognized that Jupiter had “little or no solid matter, being a sort of plastic semi-sun” (Collected Essays, Volume 3: Science H.P. Lovecraft; edited by S.T. Joshi 2005). Indeed, it has been noted that if Jupiter had a little more matter, it could have ignited to become a sun, which would have made our solar system a twin star or binary star system. Thus, if the asteroid belt is a planet that failed to form, then Jupiter is a planet that failed to become a star.
Jupiter’s most obvious feature is its Great Red Spot, which is so large that three Earths could fit in it (www.giantworlds.org). According to HPL, the Great Red Spot first appeared on Jupiter in 1878. Actually, the first formal documentation of the Great Red Spot was made in 1831 by an amateur German astronomer, Heinrich Schwabe. A permanent spot was identified on Jupiter as early as 1665, then by the Italian astronomer Gian Domenico Cassini. However, the Great Red Spot has been continuously observed since 1878, identified by American astronomer Carr Walter Pritchett. A sketch of Jupiter and its Great Spot was made by HPL and is shown in Collected Essays, Volume 3: Science H.P. Lovecraft.
Jupiter’s Great Red Spot (www.dailygalaxy.com).
Next time we will talk about Jupiter’s moons and how their numbers have increased from Galileo’s day to HPL’s time to today. Thank you – Fred.