Look! Up in the sky! It’s a dumpling … It’s a “Star Trek” Borg cube … It’s the asteroid Ryugu!
Our view of Ryugu, a half-mile-wide space rock nearly 180 million miles from Earth, is coming into sharper focus with the approach of the Japanese probe Hayabusa 2.
Three and a half years after its launch, the spacecraft is now within 35 miles of the asteroid, closing in on what’s expected to be a standoff orbital distance of 12 miles. The pictures that it’s been sending back throughout the approach provide enough detail to reveal Ryugu’s blocky shape.
“It looks like… a dango-type asteroid! (Actually, that’s a Japanese sweet dumpling. But the shape seems to be similar so far…),” the mission team tweeted last week.
The images reminded German science writer Daniel Fischer of something more ominous: the cube-shaped starship inhabited by the nefarious Borg collective in the “Star Trek” sci-fi tale. “To keep crucial shocking details from most of the world the caption exists only in Japanese,” he joked in a tweet.
As the asteroid mission proceeds, more space fans are sure to be assimilated. Around the end of July, the probe is due to descend to a distance of just a few miles, according to the schedule laid out by the Planetary Society’s Emily Lakdawalla. In August, it’ll go even closer, to 0.6 miles (1 kilometer).
All this is a prelude to the main event: Over the course of the following year, Hayabusa 2 will make a series of touchdowns on the asteroid’s surface to gather samples. Small landers and a German-built rover known as the Mobile Asteroid Surface Scout, or Mascot, will be deployed to make on-the-surface observations.
Around the end of 2019, Hayabusa 2 will leave Ryugu, and by the end of 2020 it should be back at Earth to drop off its samples.
Hayabusa 2 follows up on the first Hayabusa probe, which made a similar cosmic trek to collect samples from the asteroid Itokawa in 2005. Those samples were returned in 2010 after a journey that turned out to be more complicated than expected, due to technical problems.
NASA is in the midst of its own asteroid sample return mission, OSIRIS-REx. That probe is due to rendezvous with the asteroid Bennu in December, conduct a detailed survey, and return samples to Earth in 2023.