An hour after sunset, Venus has set but Mercury remains above the horizon, with the Moon and Saturn visible above it. Neptune lies near Saturn, viewable with optical aid. Credit: Stellarium/USGS/Celestia/Clementine

A Rare Evening Alignment

Skywatchers are in for a treat this week as Mercury reaches its greatest eastern elongation, offering excellent visibility shortly after sunset. This celestial event is further enhanced by the presence of a waxing crescent Moon, appearing near both Neptune and Saturn, creating a stunning trio in the western sky.

Mercury at its Best

On February 18th, Mercury reaches a position 18° east of the Sun, shining at magnitude –0.5. Approximately 30 minutes after sunset, it will be 11° high, appearing 8° above the brighter Venus. This makes for a lovely naked-eye observation opportunity.

Spotting the Elusive Neptune

While Saturn will be easily visible as the brightest point of light to the lower left of the Moon, Neptune requires a bit more effort. At magnitude 7.8, it’s not visible to the naked eye. However, using binoculars or a telescope, you can locate the distant ice giant by centering Saturn in your view and then looking less than a degree north.

Planetary Distances and Visibility

The Moon will pass 4° north of Neptune and 5° north of Saturn at 7 P.M. EST. Currently, Neptune and Saturn are less than a degree apart in the constellation Pisces. This close proximity makes for a fascinating observation, even if Neptune requires magnification.

Sky Conditions for Optimal Viewing

For those in locations around 40° N 90° W, sunrise occurs at 6:47 A.M. And sunset at 5:41 P.M. The Moon rises at 7:47 A.M. And sets at 8:22 P.M., currently in its waxing crescent phase (8% illumination). These times will vary based on your specific location.

Future Trends in Amateur Astronomy

The increasing accessibility of affordable, high-quality telescopes and binoculars is fueling a resurgence in amateur astronomy. Events like this planetary alignment are driving demand for tools that allow individuals to explore the night sky. Advancements in astrophotography software are making it easier than ever to capture stunning images of celestial objects from home.

The Rise of Citizen Science

Opportunities for citizen science are also growing. Amateur astronomers are increasingly contributing valuable data to professional research projects, helping to monitor variable stars, discover asteroids, and even search for exoplanets. This collaborative approach is transforming the field of astronomy.

Frequently Asked Questions

What is greatest eastern elongation?

Greatest eastern elongation is the point at which a planet appears farthest east of the Sun from our perspective on Earth, offering the best viewing conditions.

Can I see Neptune without a telescope?

No, Neptune is too faint to be seen with the naked eye. Binoculars or a telescope are required.

What magnitude is considered visible to the naked eye?

Generally, stars and planets brighter than magnitude 6.0 are visible to the naked eye under ideal conditions.

Where should I look in the sky?

Look low in the western sky shortly after sunset.

Stay up-to-date with the latest sky events by checking out our Sky This Week column.