The planet Venus stands out brightly in the evening sky, visible to the unaided eye even as twilight lingers. This week, a slender crescent moon will accompany it on the evenings of April 18 and 19. The view from London on April 19 at 8:30 p.m., roughly half an hour after sunset, shows the pair clearly in the west, with no other stars yet apparent. The moon, at 2.6 days old, will display only about 7.5% illumination, creating a striking sight. For an added test, observers can look 24 hours prior, when the moon sits lower than Venus with even less of its surface lit. Success on April 18 requires an unobstructed view to the west. Begin watching only after the sun has set to avoid eye injury from direct sunlight. The faint crescent may flicker in and out of view due to shifting air layers from daytime warmth. In the southern hemisphere, the alignment offers a higher position above the horizon for easier observation.
