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Space and Physics

Venus Is At Its Brightest In The Night Sky Tonight. Here’s Why

author

Dr. Alfredo Carpineti

Senior Staff Writer & Space Correspondent

clockApr 28 2020, 11:17 UTC

Venus in the sky. bochimsang12/Shutterstock

Venus, the second closest planet to the Sun, is one of the most clearly identifiable objects in the sky. It’s the "evening star" in the west after sunset and the "morning star" in the east after sunrise. If you've had the chance to see it over the last few weeks, you might have noticed how bright it is. Today, it will reach its point of “greatest brilliancy”.

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This is because the largest area of the planet is illuminated by the Sun, making it incredibly bright in the sky. However, its greatest brilliancy is not the exact moment of maximum brightness because the atmosphere of Venus is not a perfect reflector. Still, its brightness during this time makes it the third brightest object in the sky after the Sun and Moon. It will reach a magnitude of -4.6 – 18 times brighter than Sirius, the brightest star in the night sky.

The brightness of Venus will then drop pretty rapidly over the next month.

Venus changes in brightness and distance from Earth during the Greatest Brilliancy and inferior conjunction. National Astronomical Observatory of Japan

Due to the geometry of the orbits, Earth is currently “ahead” of Venus around the Sun and the two planets are roughly 70 million kilometers (43 million miles) apart. On June 3, the two planets will be more or less aligned with the Sun in what is known as the inferior conjunction. At a distance of less than 50 million kilometers (31 million miles), this is the closest Earth ever gets to Venus. As we approach, we see less and less sunlight reflected off Venus, and when we are at the closest distance between the two planets, its brightness will drop significantly at just over half as bright.

Due to the planets not being perfectly aligned with the Sun, some light is still reflected off Venus. On rare occasions, the three bodies are perfectly aligned and in those cases, Venus is visible crossing the solar disk as a black dot on the surface of the Sun. But these transits, as they are called, only happen rarely, with the next one in 2117.

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Don’t be glum if you have missed the spectacle lately, the planet will soon be bright again. After the conjunction, the planet will increase in brightness, reaching its "greatest brilliancy" on July 18. If July is still tough for you, then wait 517 days until the following greatest brilliancy in December 2021.

Venus and Earth's orbits and their position during some of the "special" phases of Venus. National Astronomical Observatory of Japan

Space and Physics