There is no planet that appears brighter than Venus in the night sky, and it is always a rewarding astronomical sight for solar system fans. On Tuesday, Venus reaches its maximum brightness, shining at a brilliant magnitude minus 4.5, and remains brilliant for the following weeks.

The scale by which astronomical brightness is measured can be confusing at first. It is upside down from what many would expect, with smaller numbers representing brighter stars. Any object with a negative magnitude is brighter than Vega, the benchmark star and brightest in the constellation of Lyra. The scale is also logarithmic. In this case, each whole number we go down the scale represents  minus 2.5x increase in brightness. Sirius, the brightest star in the entire night sky, is a magnitude minus 1.4. This means that at maximum brightness, Venus is a whopping 17 times brighter than Sirius.

Observing with a telescope, we find Venus to be mostly dark, appearing as a crescent similar to the familiar phase of the moon. As Venus continues on its path around the sun, this crescent will get thinner and thinner until it dips beyond the evening horizon at the end of May. After this, we have to wait for it to reappear in the morning sky in late June.

First Published: April 28, 2020, 12:00 p.m.