ISTANBUL A large comet called 3I/ATLAS, first spotted this summer, has shown signs of speeding up in a way not caused by gravity and appeared to turn blue as it passed close to the Sun, said scientists. Astrophysicist Avi Loeb of Harvard University said data from the US space agency NASA pointed to this unusual acceleration, likely caused by gas escaping from the comet. He noted that the comet could lose about half of its mass and create a large trail of debris in the coming months, Fox News