Venus
No. The Sun is
Assuming you mean in the Earth's night sky, Venus is the next brightest natural object seen from Earth.
The Moon is illuminated by the Sun. At full moon, we see the bright part - the illuminated part. At new moon, we see mostly the dark part. (This part is also slightly visible, due to light reflected from the Earth.)
We would say that the moon is the secondbrightest, after the sun.
Jupiter.
Venus is the third brightest object in the sky after the sun and moon, and the brightest planet, but only at certain times when it is at the right position in its orbit relative to the earth and sun.
Clearly the sun is the brightest object in the sky.
The brightest object in space, aside from the Sun and Moon, is the star Sirius. Sirius is the brightest star in the night sky and is located in the constellation Canis Major. It appears exceptionally bright due to its proximity to Earth and its high luminosity.
Jupiter is the second brightest in the world after the sun
The sun and the moon are not planets. The sun is a star and the moon is a natural satellite. The brightest planet in Earth's sky is Venus.
No, Jupiter is typically the 4th brightest object in the sky after the Sun, Moon, and Venus. It can vary in brightness depending on its position in its orbit and its alignment with Earth.
Venus is the brightest thing in the sky, after the Sun and Moon.