Watch a green comet pass by Earth for the first time in 50,000 years, see an asteroid swing by Earth in one of the closest ever encounters, and explore a hypothetical planet from the 1800s disproven by Einstein’s theory of relativity. Speaking of comets, asteroids, and planets…

A comet, an asteroid, and a hypothetical planet walk into the Solar System. The hypothetical planet says to the comet, “Why so green?” The comet says, “It’s the radiation from the Sun evaporating the carbon on my surface. You’d know that if you were as close to the Sun as people thought you were.” The hypothetical planet turns red with anger and ceases to exist. The asteroid says, “Phew, that was a close one!”


[h4]A Green Comet[/h4]
The green comet, C/2022 E3 (ZTF), recently passed by the Earth for the first time in 50,000 years. Explore its path and watch this once-in-a-lifetime event occur over and over with our new simulation
The Green Comet C/2022 E3 (ZTF) in 2023


[h4]Close Encounters of the Asteroid Kind[/h4]
Asteroid 2023 BU performed a close pass of Earth (though it posed no threat), only 2,200 km from the surface. That’s just under half the length of the United States! Watch one of the closest asteroid encounters ever recorded in our new simulation 
Asteroid 2023 BU Close Encounter in 2023


[h4]The Non-Existent Planet[/h4]
In the 1800s, many astronomers thought there was a planet, dubbed Vulcan, between Mercury and the Sun. Mercury’s orbit was observed to wobble slightly more than predicted, and Vulcan was hypothesized to explain this. We now know Vulcan does not exist, and general relativity causes the additional wobble, but you can see Vulcan’s proposed orbit in the new simulation
Hypothetical Planet Vulcan


[h4]More Highlights[/h4]
Landing (press "c") on the surface of a planet now always points you toward the horizon. Taking off returns you to your previous position instead of in front of the planet.



On February 3, 2023, astronomers announced the discovery of 12 more moons orbiting Jupiter. Learn about these new moons in our new simulation
Jupiter’s New Moons 2023
Or explore the history of the discovery of all of Jupiter’s 92 moons in our guide
History of Jupiter’s Moons



We added a Spherical Cow to Universe Sandbox! This refers to a joke that when physicists want to make a problem easier to handle, they sometimes simplify it so much it’s no longer realistic.



Experience 100 spherical cows hitting Earth at lightspeed in our new sim
Earth & 100 Spherical Cows at the Speed of Light
Because why not?


Check out the full list of What's New in Update 32.2

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