1) There are about 5000 stars visible with the naked eye. But, because half of the Earth is in daylight, only half of that stars would be visible. Therefore, approximately 2500 stars are visible with the naked eye in the night sky.
2) The Mizar and Alcor are the double star system located in the handle of the Big Dipper (or Plough) asterism in the constellation of Ursa Major. Mizar is the second star from the end of the Big Dipper's handle. Alcor is situated right next to the Mizar.
3) Neowise C/2020 F3 is long-period comet which has a near-parabolic orbit. This comet was discovered on March 27, 2020, by astonomers during the NEOWISE mission of the Wide-field Infrared Survey Explorer space telescope. After the approach with the Sun the comet has the semi-major axis 355 AU, eccentricity 0.99921 and orbital period approximately 6700 years. When the comet was in perihelion it had two tails. The first tail was blue color and made of gas and ions. The second tail was golden color and made of dust.
4) It's a Geminid meteor shower. It takes place in December 6-14 with the date of peak on the night of December 13-14. This shower is intensifying every year (the recent showers have seen 120-160 meteors per hour under optimal conditions). Also, the Geminid meteor shower can be seen both in Northern and Southern Hemisphere.