The celestial body known as the "morning star" is Venus. This planet is often visible shortly before sunrise or just after sunset, which has led to its nicknames, including the Morning Star and the Evening Star. Venus is the second planet from the Sun, and it is similar in size and composition to Earth, which is why it is often called Earth's "sister planet." Despite its similarities to Earth, Venus has a thick atmosphere primarily composed of carbon dioxide and sulfuric acid clouds, resulting in extreme greenhouse effects and surface temperatures hot enough to melt lead.