After the sunsets this week the constellation Leo the Lion will be setting in the western horizon. His head is formed by a few stars that look like a backward question mark. At the base is the bright star Regulus. As Regulus nears the north-western horizon it meets the bright planet Venus.
The brighter Venus is easy to spot after the Sun sets
Venus has been the evening star for several weeks. As it orbits around the Sun it has moved higher in the western evening sky. This week it is moving toward the fainter star Regulus. On the evening of Wednesday, July 21 Venus will move past Regulus about one degree north of the fainter star.
Regulus is considered one of the brightest stars seen from earth at first magnitude. The much brighter Venus is a magnitude -3.9 which makes it over 100 time brighter than Regulus.
Although these two objects look close to each other in the sky they are in reality separated by much greater distances. Venus is 1.4 astronomical units from Earth which is 130 million miles. At that distance, it takes light from Venus about 11 minutes to reach earth. Regulus is much farther at 79 light-years. At that distance it takes light from Regulus 79 years to reach earth.
Mars is not far behind. Mars is 5 degrees to the lower right of Venus. Mars will move near Regulus by July 29.
Both Mars and Regulus may be a challenge to see in the evening twilight so use a good pair to binoculars to help in locating these objects.