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Explore the Night with Bob King Lambda Aquarii Moon Neptune Observing Observing News & Current Celestial Events occultation Occultations planets 

See Two Tricky Occultations — Neptune and Lambda (λ) Aqr

Now you see ’em, now you don’t. Watch the Moon occult Neptune and nearby Lambda Aquarii on the same night. On July 22-23, the waning gibbous moon occults Neptune, here shown during its simulated reappearance. The planet’s tiny 2.3″ aqua disk is dwarfed by the Moon. Stellarium I love magic. It always makes me feel so dumb. That’s probably because I’m terrible at figuring out magic tricks. Levitating tables? Death saw? Keep ’em coming! A favorite trick is to make a quarter disappear and then pull it out of someone’s ear, a…

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What are the Different Masses of the Planets?

It is a well known fact that the planets of the Solar System vary considerably in terms of size. For instance, the planets of the inner Solar System are smaller and denser than the gas/ice giants of the outer Solar System. And in some cases, planets can actually be smaller than the largest moons. But a planet’s size is not necessarily proportional to its mass. In the end, how massive a planet is has more to do with its composition and density. So while a planet like Mercury may…

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