Earth’s closest planetary neighbor is shining brighter this week than it will all year, which means that, yet again, it’s a great time to do some stargazing.
Venus has been easy to spot for days now, but it will be at its brightest on Friday morning, shining two-and-a-half times brighter than it does at its dimmest point. In astronomer-speak, it will be at its greatest illuminated extent, so bright that you might be able to see it after the sun rises.
Here’s how it works.
Because it’s closer to the sun than the earth is, Venus has moonlike phases. When it’s directly between the earth and the sun, at what’s called the inferior conjunction, none of the side illuminated by the sun can be seen. Near this point, it appears as a crescent.
At its furthest point, the superior conjunction, Venus can’t be seen from Earth because the sun is in the way. Near this point, it appears as a Gibbous, with most of its illuminated side visible to earth.
How bright Venus appears depends on both its proximity to earth (closer means it’s brighter in the night sky) and its phase (farther means it’s more surface area visible). These factors are in tension, so the greatest illuminated extent happens at something of a sweet spot, about 72 days before and 72 days after inferior conjunction.
To see the show, all you have to do is look east before dawn. The exact time Venus will rise depends on where exactly you are. For instance, in New York Venus will rise at 3:08 a.m. on Friday morning while in San Francisco, you’ll be able to see it starting at 3:28 a.m. You can look up your own location at timeanddate.com.
And as a special bonus, Venus is also going to be positioned quite close to Aldebaran, the brightest star in the constellation Taurus, the one that makes up the eye of the bull. That’s two celestial bodies for the price of one, and a good reason to drag yourself out of bed early tomorrow morning.