NASA, ESA, and D. Jewitt (UCLA)
These two Hubble images captured comet Borisov streaking past the Sun on its way back to interstellar space. It is only the second interstellar object known to have passed through the solar system. The image on the left was taken on November 16, when the comet was 203 million miles from Earth. The image on the right was taken on December 9, when the comet made its closest approach to the Sun.
The core of the comet is no more that 3,200 feet across, too small to be seen by Hubble. But the huge, surrounding cloud of dust streaming off the nucleus is much larger in diameter than Earth.