Published: 2016-12-07 11:49:36
Updated: 2016-12-07 11:49:36
Posted December 7, 2016
By Tony Rice
You may have seen videos or images on Facebook or other social media websites claiming that "all of the planets in our solar system can fit between Earth and the Moon."
You probably wondered how accurate that claim is?
First, kudos for looking at information shared on social media, especially science-related information, with a critical eye. We should all do this more.
The answer: It depends.
Many versions of the image, including the original posted to Reddit by user CapnTrip, use the average distance between the Earth and Moon of 384,000 km to measure the claim.
While these claims have the mean lunar distance correct (within a couple of kilometers), problems lie in calculations of the total diameters of the planets.
From NASA’s Space Science Data Coordinated Archive, we know the sum of the diameters of Mercury (4879 km), Venus (12,104 km), Mars (6792 km), Jupiter(142,984), Saturn (120,536 km), Uranus (51,118 km), Neptune (49,528 km) and Pluto (2370 km) is 390,311 km.
NO, planets of our solar system, with or without Pluto, cannot fit within the mean lunar distance. An additional 3,500 km is needed to squeeze in Neptune (5,900 km to include Pluto).
Supermoon fans know that the distance between the Earth and the Moon varies. At perigee, when the moon comes closest to the Earth, there is enough room for everything but Neptune and Pluto.
Apogee, when the moon’s orbit takes it furthest from Earth, is 406,700 km away.
So, with or without Pluto, the solar system can fit between the Earth and the moon but only near apogee and not the average lunar distance seen in social media.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.