Comet 2I/Borisov Approaches Earth
On Saturday, December 28, 2019, the interstellar comet 2I/Borisov will make its closest approach to Earth, on its way through our Solar system.
As we wrote earlier, all of December the Interstellar comet 2I/Borisov, the first comet ever observed from outside our Solar system and only the second interstellar object ever observed, is well placed for observation.
Scientists expect that around December 28, 2019, comet 2I/Borisov will pass 180 million miles (290 million km) from Earth, its closest approach to our planet, and then it will begin to leave our Solar system forever. That's twice the distance between the Earth and the Sun. According to NASA, comet 2I/Borisov will pass through the constellations Crater and Hydra and will be too dim to see without a telescope. Around its closest approach to Earth, comet 2I/Borisov will be passing beyond the orbit of Mars, which means that it will not be a threat to our planet.
Comet 2I/Borisov is traveling through the Solar system at 110,000 mph (160934 km/h) and looks a lot like other long-period comets. Its size isn’t yet well understood. According to NASA, is likely no more than 3,200 feet (about 1 km) across.
You can find more information about the comet 2I/Borisov and track its movement across the sky in the astronomy app Star Walk 2.