By David Freeman
A large asteroid and its tiny companion moon raced harmlessly over the earth this weekend.
The so-called binary asteroid, called 1999 KW4, will make its next approach at 19:05 ET: When the paired objects are approximately 5 million kilometers from Earth and move at a speed of approximately 80,000 kilometers per hour ,
Although KW4 is classified as a potentially dangerous asteroid in 1
] "It's probably one of the closest binary flights in recent history," said Vishnu Reddy, a planetary scientist at the University of Arizona in Tucson. "That's what makes it a very interesting destination."
According to Reddy, the asteroid will be too weak even at its next approach to be seen with the naked eye.
Asteroid 1999 KW4 was discovered on May 20, 1999
Observations show that the primary or alpha object is about 1.3 km wide and the shape of a spinning tip has a prominent crest around its equator. The smaller or beta object is about one-third the size of the alpha object and orbits the latter at a distance of about 2.6 miles.
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