You are here

Venus and Mercury

March 5, 2018

The Sun’s closest planets are standing close to each other in the early evening sky right now. They’re bright, but they’re quite low, so you need a clear horizon to spot them. They’ll move higher into the sky over the next few nights, though, making them easier to find.

Venus and Mercury are in the west at sunset. They’ll pop into view as the sky begins to darken. Venus is the brighter of the two. Tonight, Mercury is close to its upper right. It’s not as bright as Venus, but its proximity to the “evening star” should help you pick it out.

Mercury is the smallest major planet in the solar system — about half-again the diameter of the Moon. And its surface looks a lot like the Moon’s — a landscape of craters, canyons, and tall cliffs.

Mercury is the closest planet to the Sun, so it’s extremely hot — daytime temperatures at the equator can climb to about 800 degrees Fahrenheit.

Venus is farther from the Sun, yet it’s hotter than Mercury. That’s because it has a thick atmosphere that’s made of carbon dioxide, topped by a solid layer of clouds. They act as a blanket — they trap energy from the Sun, making Venus the hottest world in the solar system.

Watch Venus as it climbs away from the Sun over the coming months. Mercury will climb above Venus for a few days, then drop back toward the Sun — leaving Venus to dominate the western evening sky for much of the year.

Script by Damond Benningfield

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.