For a short interval this yr, Earth had an additional moon. The article, known as 2020 CD3, was noticed hurtling across the sky in February. After calculating its orbit, astronomers discovered it had in all probability been gravitationally certain to Earth for about three years earlier than anybody seen. By learning its brightness, they calculated that it was in all probability between 1.9 and three.5 metres throughout – concerning the dimension of a automobile.
On the time, it wasn’t 100 per cent clear whether or not this was a pure object or only a piece of synthetic area particles. Now we’re pretty certain that it was pure, says Grigori Fedorets at Queen’s College Belfast within the UK. His team has also confirmed its diameter is about 1.2 metres, or across the top of a 6-year-old.
Shortly after 2020 CD3 grew to become invisible to us, astronomers noticed one other object, known as 2020 SO, approaching Earth. It, too, was briefly captured in our orbit, however astronomers had been uncertain whether or not it was a pure or synthetic object. Additional evaluation in December confirmed that 2020 SO is definitely a discarded rocket booster from the 1960s, leaving 2020 CD3 as solely the second momentary minimoon we’ve got ever discovered.
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