There was a test ion engine a few years ago that was used to go some distance, I don't think I ever heard any report about mention the distance, but it was shut off not long after it was started. I onyt saw the mention once, so I don't remember details.
Apophis asteroid might be more likely to strike Earth in 2068 than thought
Let's just hope @Brink and the rest of the Asgard protect usThe asteroid Apophis was first spotted by astronomers back in 2004. Shortly thereafter, researchers worked out its orbital path and found that the 340-meter-wide asteroid would pass near to the Earth in 2029, 2036 and again in 2068. More study showed that there was little chance of the asteroid striking Earth; thus, it was discounted as a threat.
More recently, Tholen and his team noted that earlier researchers had not accounted for the Yarkovsky effect by which from the sun strikes one side of an asteroid. As the heat radiates away from the asteroid, a small amount of energy pushes back against the asteroid, forcing it to turn slightly. Tholen and his team calculated that the Yarkovsky effect is pushing Apophis to one side enough to force it to drift by approximately 170 meters a year. They next applied that bit of knowledge to the math describing Apophis's orbit and found that the drift is changing the course of the asteroid in a way that will bring it closer to Earth. He notes that thus far, there is no indication that the asteroid will strike the Earth in 2029 and 2036, but 2068 might be another matter.
He suggests that astronomers will have to keep an eye on Apophis as its rendezvous date approaches.
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