Can Venus cast a shadow? Here's how to see it for yourself
As Venus gets close to its greatest brilliancy in the evening sky, it’s a good time to test one of astronomy’s less believable claims.
by Jamie Carter · Space
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Can Venus cast a shadow? With Aug. 12's total solar eclipse — where the moon's dark silhouette is everything — now behind us, it's a good time to test another kind of celestial shadow.
Astronomical folklore has it that the second rock from the sun, Venus, is, after the sun and moon, the third object able to cast a shadow when it's near peak brightness, albeit extremely faint, according to EarthSky.
Is it true? Not in a city, where skylights glow and porch lights blaze, where shadows are mostly thrown by passing cars that appear to become the brightest object in the solar system briefly. Venus does cast a shadow, but the sky must be very dark, transparent and free of any light — apparently.
Timing is everything. Having reached dichotomy — its half-lit phase — on Aug. 12, Venus is currently 49%-lit and waning as it moves closer to Earth, increasing in angular size as it becomes a slim crescent. Cue a surge in brightness, thanks to its reflective clouds and its closeness. Shouldn't it be brightest when it's "full?" No, because it's an inferior planet — i.e., it orbits closer to the sun — so it's fully lit only when it's on the other side of the sun from Earth, when its disk appears at its smallest.
What’s happening and when to look
Venus is beautifully placed this week because it reaches greatest eastern elongation, its widest apparent separation from the sun in the evening sky. Look low in the west after sunset — Venus will be the bright white "star" that appears before the fainter stars even have a chance.
On Aug. 14-15, it sits about 46 degrees from the sun and shines at a magnitude of -4.3 to -4.4, bright enough to dominate twilight but not quite at its most impressive stage of the apparition. The real test comes around Sept. 18, when Venus reaches its greatest brilliancy at magnitude -4.6. Sadly, by then it's going to be rather low in the sky from mid-northern latitudes, making observation from the U.K. difficult, but possible from most of the U.S.
How and when I’m watching it
According to Sky & Telescope, to catch a faint but well-defined shadow of Venus — a point source of light — you'll need to be somewhere free from artificial lighting and wait until twilight is over. Face Venus and place a white surface (a white card or sheet works well) also facing Venus. You'll also need to position something in front of the card to cast a shadow. Although it is possible to see the faint shadow of Venus, photographing the card is the best way to capture it, using a technique similar to that for any night sky photograph — a high ISO, a wide aperture and a long exposure of up to 30 seconds. It may be wise to test the location, find the best line of sight, and work out where the card needs to go while Venus is still high enough above the western horizon.
If you're not in a good location to catch the shadow of Venus, instead try to see and photograph the light from Venus reflecting on water. Any pond, lake or ocean you can get between you and Venus ought to catch its shine in a long exposure image. That identical technique — high ISO, a wide aperture and a long exposure — will also apply, but this time you can actually aim your camera at Venus!
Stargazer’s Corner: August 14-20, 2026
This is an excellent week for darkness and faint objects. With new moon on Aug. 12, this week is all about a crescent moon. On Aug. 15 you may catch a 12%-lit waxing crescent close to Venus, but more likely you'll see it on Aug, 16, when it will be 19%-lit. The latter occasion is one to aim for — a beautiful sight. On both occasions, look for "earthshine" on the darkened limb of the moon — sunlight reflected by Earth, and something else you can try to capture with a long exposure. The waxing crescent moon will be low in the western evening sky, but early in the week it sets early enough to leave most of the night usable for stargazing and deep-sky astronomy.
The buzz around the Perseid meteor shower, like the solar eclipse, will by now have completely dissipated, but they're still active after their Aug. 12-13 peak, though rates will be lower. With the moon mostly out of the way, it is still worth spending time outside after midnight in the hope of finding "shooting stars." However, the main attraction during dark nights in August is the Milky Way, which streams through the Summer Triangle to Scorpius and Sagittarius. Every time I see the Summer Triangle stars high in the night sky, I tell myself that the Milky Way is right there — and hidden from us by light pollution. It's a reminder to get to a dark-sky site as much as possible when the moon is down (the period between last-quarter moon and new moon is the best week of any month).
Constellation of the week: Scorpius
Scorpius is one of the most distinctive constellations visible from mid-northern latitudes, though it never climbs very high. Its bright red star Antares marks the heart of the scorpion, with a curving tail extending downward toward the horizon. You can see Antares above Venus as it gets dark — a bright, dominating star that's a waymarker of summer in the Northern Hemisphere.
Even in brighter skies, its shape is recognizable, forming a hooked pattern that stands out from the surrounding stars. Because it sits low in the south, it's best observed earlier in the evening before it begins to set. It's one of the few constellations that genuinely resembles its name — and it's where to see the Milky Way meet the horizon.