---
title: "Watch the Rare “Triple Transit” From Jupiter’s Moons"
description: "## Jupiter’s Triple Transit"
date: "2021-08-22"
modified: "2021-08-22"
authors:
  - name: "Tony Ho Tran"
    link: "https://futurism.com/authors/ttran"
url: "https://futurism.com/the-byte/triple-transit-jupiters-moons"
categories:
  - "Astronomy"
  - "Moon"
  - "Space"
tags:
  - "Astronomy"
  - "jupiter"
  - "the digest"
  - "triple transit"
---

# Watch the Rare “Triple Transit” From Jupiter’s Moons

![](<https://futurism.com/wp-content/uploads/2021/08/MOSHED-2021-8-22-14-14-9.jpg>)
*Christopher Go/Kunio Sayanagi \<em\>Image: Christopher Go/Kunio Sayanagi/Tony Tran\</em\>*

## Jupiter’s Triple Transit

Astronomers were treated to a delightful show last week when three of Jupiter’s moons passed in front of the planet in a rare event known as a "triple transit."

The moons in question are three of Jupiter’s Galilean moons: Europa, Ganymede, and Callisto, [according to *The Washington Post*](<https://www.washingtonpost.com/weather/2021/08/21/jupiter-transit-moons-mutual-2021/>)*.* They were named such as they were discovered by Galleleo in 1610. The three passed in front of the planet on August 15, completing a rare triple transit in doing so.

The last triple transit occurred in 2015, while the next is slated for 2032. If you missed it, don’t worry. You can check out the gif of it below:

https://twitter.com/TonyHoWasHere/status/1429516395688169477

## Partial Eclipse of the Moon

The triple transit wasn’t the only rare astronomical event to occur that day. In fact, something called "mutual events" happened as well.

It occurred when Europa passed out of Earthlings’ sightline underneath Ganymede. When the moon reappeared, Ganymede threw its shadow on Europa causing an eclipse.

![](<https://futurism.com/wp-content/uploads/2021/08/christopher-go.jpg>)
*Christopher Go/Kunio Sayanagi*

"This thing is so surreal," said Christopher Go, an astronomer and photographer who captured the stunning images of the triple transit and mutual events from Cebu City, Philippines. "Ganymede is projecting a shadow toward Jupiter, but part of the shadow hit Europa."

Space enthusiasts everywhere have folks like Go to thank for capturing and archiving such amazing astronomical events. In fact, the only reason much of the world is aware of it now is because [NASA featured Go’s images as their Astronomy Picture of the Day yesterday](<https://apod.nasa.gov/apod/ap210821.html>).

**READ MORE:** [Watch this 'surreal' Jupiter eclipse that you probably missed](<https://www.washingtonpost.com/weather/2021/08/21/jupiter-transit-moons-mutual-2021/>) \[*The Washington Post*\]

**More on Jupiter’s moons:** [*NASA’s Juno Probe Creates Stunning Map of Jupiter’s Largest Moon*](<https://futurism.com/the-byte/nasa-juno-map-jupiter-ganymede>)

## Author
Tony Tran is a former reporter for Futurism, and now an editor at the Daily Beast. His work has been seen in Playboy, HuffPost, Narratively, and wherever else fine writing is published. He lives in Chicago where he frequently plans tabletop gaming sessions for his friends.