On this day in space! Aug. 28, 1993: Galileo spacecraft flies by asteroid Ida on the way to Jupiter only to find a tiny moon!

On Aug. 28, 1993, NASA’s Galileo spacecraft flew by the asteroid Ida whereas on its technique to Jupiter.

Galileo was the primary spacecraft to fly by an asteroid within the asteroid belt. Ida was really the second it visited after one other flyby of the asteroid Gaspra in 1991.

Galileo whizzed by asteroid Ida going virtually 28,000 mph and got here inside 1,500 miles of the asteroid’s floor. Throughout the encounter, Galileo really found a tiny moon orbiting Ida! This was the primary confirmed satellite of an asteroid. The Worldwide Astronomical Union named the moon Dactyl after a bunch of mythological beings who lived on a sacred mountain referred to as Mount Ida.

Why it mattered

In the mid-1990s, the Galileo spacecraft, on its way to the Jupiter system, captured this mind-blowing image of asteroid 243 Ida and its moon, Dactyl, on Aug. 28, 1993. — The Galileo spacecraft, on its technique to the Jupiter system, captured this mind-blowing picture of asteroid 243 Ida and its moon, Dactyl. (Picture credit score: NASA/JPL)

Asteroid 243 Ida was really the second asteroid ever to be visited by a spacecraft (Galileo beforehand flew by the asteroid Gaspra in October 1991), however this flyby clinched the speculation that asteroids could have moons.

Till the Galileo spacecraft photographed Ida and Dactyl, astronomers suspected some asteroids may have their very own moons, however Galileo proved it as soon as and for all. Throughout the flyby, Galileo approached inside 1,500 miles (2,400 kilometers) of Ida because it made its technique to Jupiter.

“It was beforehand thought that pure satellites of asteroids may type, however they most likely weren’t frequent,” Torrence Johnson, Galileo’s venture scientist, as soon as mentioned of the flyby in a NASA statement. “Having discovered one pretty shortly, we are able to say that they are most likely extra frequent than beforehand thought.”

Ida is an S-type asteroid made principally of silicate rock and sits in the principle asteroid belt. Astronomers suspect it’s what’s referred to as a Koronis asteroid, leftover particles from an historic crash of two a lot bigger objects, in response to NASA. It was found on Sept. 29, 1884 by Austrian astronomer Johann Palisa on the Vienna Observatory.

Galileo imaging group member Ann Harch really found Ida’s moon Dactyl on Feb. 17, 1994, months after the flyby, whereas reviewing information, NASA mentioned.

Galileo didn’t cease to check Ida and Dactyl. As with its Gaspra flyby, the probe zoomed by to proceed its journey to Jupiter. NASA launched the Galileo mission on Oct. 18, 1989 and it arrived at Jupiter on Dec. 7, 1995, orbiting the enormous planet for practically 8 years. The mission ended on Sept. 21, 2003, when Galileo intentionally crashed into Jupiter.

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