Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

When in its orbit does Venus appear brightest?

RELATED TOPICS: VENUS
The Sun-Earth-Venus geometry gives us many observing highlights.
The Sun-Earth-Venus geometry gives us many observing highlights, all illustrated in this diagram.
Astronomy: Roen Kelly, after Holley Y. Bakich

Q: The closer Venus gets to Earth as it orbits, and the larger it grows, the skinnier its crescent phase. So at what point in its orbit does Venus appear brightest?

David T. Wolf
San Carlos, California

A: Because Venus is closer to the Sun than Earth, it goes through a pattern of inferior conjunction (when it lies between the Sun and Earth), greatest western elongation (when we see it farthest from the Sun in the morning sky), superior conjunction (when it lies on the opposite side of the Sun from Earth), and greatest eastern elongation (when we see it farthest from the Sun in the evening sky).

The planet also reaches two points in its orbit when the Sun-Earth-Venus angle lets us see it at its brightest. These events, known as greatest brilliancy, occur when Venus lies at an elongation of 39°, approximately 36 days before and after inferior conjunction. These two points are where the illuminated fraction of Venus and its distance from Earth work together to maximize the amount of light we detect from our sister planet.
Michael E. Bakich
Senior Editor
0

JOIN THE DISCUSSION

Read and share your comments on this article
ADVERTISEMENT
FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. View our Privacy Policy.

ADVERTISEMENT
ADVERTISEMENT
Apollo_RightRail
A chronicle of the first steps on the Moon, and what it took to get there.