See Mercury at its best in the night sky over the next 2 weeks
When you buy through links on our articles, Future and its syndication partners may earn a commission.
We now have a fine opportunity to view the planet that many astronomy guide books refer to as the most difficult of the naked-eye planets to see. The planet in question is Mercury.
Beginning now and running through the end of the second week of March, this somewhat overgrown version of the moon will have an evening appearance about as favorable as we northerners ever get to see.
In general, the most favorable elongations of Mercury — morning or evening — are those when the planet rises or sets in a dark sky, and that situation will occur for a five-day interval beginning later this week. From March 5 through March 10, Mercury will set at, or shortly after the end of evening twilight, more than 1 hour 30 minutes after sunset for mid-northern latitudes.
Mercury is popularly known as the "elusive" planet. Read what the New Handbook of the Heavens — considered one of the best guides to the stars for the amateur astronomer — said about Mercury:
"It stays close to the sun like a child clinging to its mother's apron strings, because you must look for it so soon after sunset or before sunrise, there was a famous astronomer, Nicolaus Copernicus, who never saw the planet in all of his life."
And yet, despite its reputation, Mercury is not really that difficult to spot; just find a reasonably unobstructed horizon. A clear, haze-free sky also helps. The remark about Copernicus is rather ironic, for he was the man who pushed hard for placing the sun and not the Earth at the center of our solar system.
Although the climate of Copernicus' homeland (Poland) tended to be rather cloudy and misty, one would have to believe that such a noteworthy figure in the field of astronomical calculation must have surely tried on those occasions when the weather was more favorable. Indeed, Mercury was far from impossible to glimpse during elongations as favorable as the upcoming one.
TOP TELESCOPE PICK:
Want to see planets like Mercury in the night sky? The Celestron NexStar 4SE is ideal for beginners wanting quality, reliable and quick views of celestial objects. For a more in-depth look, see our Celestron NexStar 4SE review.
During the first two weeks of March, Mercury will have an advantage in that it will be positioned not very far from the most dazzling of all the planets, Venus. In fact, we strongly encourage you to use Venus as your landmark to locate Mercury. And on March 1, another celestial object will help point the way to this rocky little planet: the moon.
Currently, Mercury sets about 90 minutes after sunset; about a half hour after sundown look for it about 10 degrees above the west-southwest horizon. Your clenched fist held at arm's length measures roughly 10 degrees, so "one fist up" from the horizon should bring you to Mercury. You'll have no trouble in seeing it as a very bright "star" glowing with just a trace of a yellowish-orange tinge.
On March 1, Mercury is shining at a very bright magnitude of –1.0. In fact, among the stars and planets, Mercury will rank only behind Venus, Jupiter and Sirius (the brightest star) in terms of brightness.
But to make absolutely sure that you're looking at Mercury, brilliant Venus will be hovering about 15 degrees ("1.5 fists") above and slightly to the right of it, while floating about 10 degrees ("one fist") above and slightly to Mercury's left will be a slender, 5% illuminated, waxing crescent moon, almost mimicking the smile of a Cheshire cat against the twilight sky; a great occasion to make a positive identification of the so-called elusive planet using our nearest neighbor in space as a pointer.
After March 1, the moon will quickly move away to the east, but Mercury will continue to interact with Venus, drawing closer to it, while moving to its lower left. In the evenings that follow, Mercury will diminish — slowly at first — in brightness, but it will also be reaching its greatest elongation, 18-degrees to the east of the sun, on March 8. Shining then at a magnitude of -0.2 (just a trifle brighter than the similarly hued star Arcturus), Mercury should be readily visible, appearing low in the western sky and setting more than 1.5 hours after the sun.
Finally, on the evening of March 12, Mercury and Venus will be closest to each other, separated by 5.5 degrees, and appearing almost side-by-side — Mercury positioned to the left of Venus — as they descend down the western sky. By that time, Mercury will have faded to magnitude +0.7.
Mercury, like Venus, appears to go through phases like the moon. Right now, it resembles a gibbous phase, about 73% illuminated, which is why it currently appears very bright. By the time it arrives at its greatest elongation, it will appear less than half-illuminated (44%) and the amount of its surface illuminated by the sun will continue to decrease in the days thereafter. So, when it begins to turn back toward the sun's vicinity after March 8th, it will fade at a rather rapid pace.
In fact, on the evening of March 15, Mercury's brightness will have dropped to magnitude +1.6; as bright as the star Castor in Gemini and only 1/11 as bright as it is now. In telescopes it will appear as a narrowing crescent phase only 16% illuminated. This, in all likelihood will be your last view of it, for the combination of its rapid fading and its descent into the brighter sunset glow will finally render Mercury invisible after mid-March. With binoculars, you might try scanning to the left of Venus for a couple of more evenings after the 15th to try and extend your view of Mercury, but for all intents and purposes it will be gone by St. Patrick's Day.
In old Roman legends, Mercury was the swift-footed messenger of the gods. The planet is well named for because it's the closest planet to the sun it's also the swiftest of the sun's family of eight planets, averaging about 30 miles per second and completing one circuit of the sun in only 88 Earth days.
Interestingly, the time it takes Mercury to rotate once on its axis is 59 days, so that all parts of its surface experiences periods of intense heat and extreme cold. Although its mean distance from the Sun is only 36 million miles (58 million km), Mercury experiences by far the greatest range of temperatures: nearly 900°F (482°C) on its day side; -300°F (-184°C) on its night side.
In the pre-Christian era, this planet actually had two names, as it was not realized it could alternately appear on one side of the sun and then the other. Mercury was called Mercury when in the evening sky, but was known as Apollo when it appeared in the morning. It is said that Pythagoras, about the fifth century B.C., pointed out that they were both one and the same.
Want to see planets like Mercury in the night sky? Our guides to the best telescopes and best binoculars are helpful tools for anyone hoping to get a closer look at the cosmos.
And if you're looking to take photos of the night sky or the planets, check out our guides on how to photograph the planets, how to shoot the night sky, and our guides to the best cameras for astrophotography and best lenses for astrophotography.
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications.
Editor's Note: If you get a good photo of Mercury, and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com.
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
2 days ago
- Yahoo
Does the color purple really exist?
When you buy through links on our articles, Future and its syndication partners may earn a commission. The world is awash with the color purple — lavender flowers, amethyst gemstones, plums, eggplants and purple emperor butterflies. But if you look closely at the visible-light portion of the electromagnetic spectrum, you'll notice that purple (which is different from bluish hues of violet and indigo) is absent. That's because purple may be made up by our brains; It exists only because of how the brain processes color. So does that mean purple doesn't really exist? Not necessarily. The answer lies within the mind-boggling way that our brains perceive and combine different wavelengths on the visible light spectrum. "I would actually say that none of color actually exists," said Zab Johnson, an executive director and senior fellow at the Wharton Neuroscience Initiative at the University of Pennsylvania. "It's all the process of our neural machinery, and that's sort of both the beauty and the complexity of it all at the same time." Sign up for our newsletter Sign up for our weekly Life's Little Mysteries newsletter to get the latest mysteries before they appear online. All color begins with light. When radiation from the sun hits Earth, a range of wavelengths are present. There are long wavelengths, like infrared rays and radio waves, and shorter, high-energy wavelengths, like X-rays and ultraviolet rays, which are damaging to our bodies, Johnson told Live Science. Toward the middle of the electromagnetic spectrum lies visible light — the light our brains can see — which represents only about 0.0035% of the electromagnetic spectrum. This is what we perceive as the colors of the rainbow. On one end of the spectrum are longer wavelengths, which we perceive as red, and on the other are shorter wavelengths, which we perceive as indigo and violet. Our perception of color involves specialized receptors at the back of our eyeballs, called cones, that detect visible light. Human eyes have three types of cones: long wave, mid wave and short wave. Each is sensitive to particular wavelengths. Long-wavelength cones take in information on reddish light, mid-wavelength cones specialize in green, and short-wavelength cones detect blue. Related: What color is the universe? When light hits our eyeballs, these three receptors take in information about the light and their respective wavelengths and send electrical signals to the brain. The brain then takes that information and makes an average deduction of what it's seeing. "Our machinery is sort of doing this complex sort of calculation of these three different ratios all the time," which forms our perception of color, Johnson said. For example, if long-wavelength and mid-wavelength cones are triggered, the brain infers that we're seeing orange or yellow. If mid-wavelength and short-wavelength cones are activated, the brain will make a conclusion of teal. So what about purple? When short-wavelength (blue) and long-wavelength (red) cones are stimulated, your brain "makes something that's actually not out there in the world," Johnson said. Red and blue are on opposite ends of the visible spectrum: When the brain encounters these wavelengths, it ends up bending this linear visible spectrum into a circle. In other words, it brings red and blue together to make purple and magenta, even though that's not what light is really doing. As a result, purple and magenta are known as "nonspectral" colors, because they don't really exist as actual electromagnetic radiation. Nonspectral colors like purple are made of two wavelengths of light. In contrast, spectral colors — red, orange, yellow, green, blue, indigo and, importantly, violet and indigo — are made of just one wavelength. RELATED MYSTERIES —Why is the sky blue? —Why do we see colors that aren't there? —What would colors look like on other planets? Regardless of its physical existence, purple has captivated people for millennia, noted Narayan Khandekar, director of the Straus Center for Conservation and Technical Studies at Harvard Art Museums. For example, ancient Phoenicians ground up sea snails to make a color known as Tyrian purple, which was reserved for royal or ceremonial robes. Today, purple is still often associated with wealth, power and even magic. "So that connection still exists, even though there are other versions of purple available now," he told Live Science. So, whether manufactured in our minds or made from ground-up shellfish, purple is unique and deserves closer look. "It doesn't really exist in nature. And so when you can create it, it has this extra value," Johnson said. "Now purple is even more special."
Yahoo
2 days ago
- Yahoo
'Completely new and totally unexpected finding': Iron deficiency in pregnancy can cause 'male' mice to develop female organs
When you buy through links on our articles, Future and its syndication partners may earn a commission. Iron deficiency during pregnancy can cause a male mouse embryo to develop female features, a new study reveals. The low iron disrupts the activation of a key gene that spurs the development of male sex organs. This causes embryos with XY chromosomes — the most common combination seen in males — to develop female sex organs instead. "This is a completely new and totally unexpected finding," study co-author Peter Koopman, a professor emeritus of developmental biology at the University of Queensland in Australia, told Live Science. "It's never been shown before that iron can flip such an important developmental switch." Earlier research established that the SRY gene on the Y chromosome is the "master switch" for turning on the development of male organs in mammals. An enzyme called JMJD1A plays an important role in flipping this master switch, and it requires iron to function properly. However, the connection between iron levels and sex determination was not fully understood. Now, in a study published June 4 in the journal Nature, researchers report that iron is essential for the development of testes in XY mice. The results show that maternal iron deficiency disrupts the activity of JMJD1A, which lowers SRY expression and drives the development of ovaries in XY mouse embryos. However, it's too early to say whether this finding in mice might translate to human pregnancy and sex development, Tony Gamble, an associate professor of biological sciences at Marquette University in Milwaukee who wasn't involved in the study, told Live Science. Related: Is there really a difference between male and female brains? Emerging science is revealing the answer. In the study, the researchers used pharmaceutical treatments and low-iron diets to manipulate the iron levels in pregnant mice. When the pregnant mice experienced iron deficiency, this caused six out of 39 total XY embryos to develop ovaries instead of testes. Investigating further, they found that genetics appear to be a factor in which embryos are sensitive to this effect. To confirm this mechanism, the team also grew embryonic gonads — structures that develop into testes or ovaries in the womb — in lab dishes so they could directly observe the impact of iron depletion. These lab analyses showed that reducing the iron in cells to 40% of normal levels led to a large increase in histones on the SRY gene. Histones are proteins that bind DNA and help control which genes are switched on, and this effect almost completely blocked the SRY gene's expression. Normally, the JMJD1A enzyme rids the SRY gene of histones, allowing it to turn on. The researchers hypothesize that when iron levels drop, the enzyme's activity is compromised, so suppressive histones build up on the SRY gene. These results suggest that "some important developmental traits that were previously thought to be purely genetically controlled can also be seriously impacted by nutrition and metabolic factors," Koopman said. And "if iron can have such an impact on sex development, then maybe other organ systems may also critically depend on iron or other dietary factors in a similar way," he added. Because the research was conducted solely in mice, the question of whether iron may have similar effects in humans is still open. Although sex determination follows a broadly similar blueprint across mammals, there are some important differences between mice and humans, Gamble said. RELATED STORIES —Scientists made mice with Y chromosomes female by deleting just 6 tiny molecules —One in 500 men may carry an extra sex chromosome (most without knowing it) —These bacteria trigger a sex change in wasps — scientists finally know how For example, while both species rely on the same genes to drive the development of testes, the consequences of mutations in these genes differ between the two species. Their similarities to humans make mice important models for studying development and disease, Gamble said, "but the differences urge caution in simply assuming processes are acting identically across both species." Testing the new finding in humans won't be easy, since many of the experiments possible in mice can't ethically be done in humans, Koopman said. "So, the way forward will have to involve doing biochemical, cell culture and gene expression experiments to build a body of indirect evidence that what holds true in mice is also the case in humans," he said.
Yahoo
2 days ago
- Yahoo
June's Strawberry Moon treats skywatchers to a rare low-riding show (photos)
When you buy through links on our articles, Future and its syndication partners may earn a commission. June's full 'Strawberry Moon' lit up the night sky last night, treating skywatchers to a rare once-in-a-18-year display as it rode low across the southern horizon. Skywatchers were served the lowest full moon in almost two decades, thanks in part to a quirk of orbital mechanics known to astronomers as a "major lunar standstill". This phenomenon occurs over a two-year period when the moon's tilted orbit is at its greatest inclination relative to our planet's celestial equator (which is essentially Earth's normal equator projected out into space). During a major lunar standstill, the moon can be seen rising and setting at more extreme positions on the horizon, while tracking a very high — or low — path through the night sky depending on the time of year. June's Strawberry Moon occurs close to the southern solstice for those in the southern hemisphere, which means that it's never particularly high in the sky to begin with. The major lunar standstill exacerbated this effect, making the June full moon the lowest full moon in almost two decades. This month's full Strawberry Moon was named for the brief fruit picking season that occurs around this time each year by Algonquian, according to the Old Farmer's Almanac. Read on to see the best pictures of the 2025 Strawberry Moon as captured by the global astrophotography community. As always, if you missed last night's full moon don't worry. The lunar disk will continue to appear (almost) fully lit for the next few nights, so be sure to read up on the best practices for observing and photographing the lunar surface as it transitions to a waning gibbous moon in the coming days. Space enthusiast Marwella Zhang was able to capture this detailed portrait of the Flower Moon around midnight from Bangka Island in Indonesia, while grappling with the haze caused by tropical storm Wutip. "After sunset, the sky was starting to get clear," Zhang told in an email. "I took my first shot, but the sky was still hazy. By midnight, as it had been predicted, the sky got clear, and I took the opportunity to get a better shot of the moon." New York's photography contingent also showed up in force to capture stunning compositions of the full moon framed by the iconic city skyline. Photographer Gary Hershorn was able to position himself to capture the orange orb of the Strawberry Moon hanging above the spire of the Empire State Building on the night of June 10. Hershorn also used a powerful lens to snap the moment Earth's natural satellite appeared to brush up against the famous landmark, creating a colorful scene that blends the warm reflected sunlight bouncing off the lunar surface with the glow of the city beneath. Kristin Louise Raught caught a striking view of the Strawberry Moon hanging over the ghostly form of Mt. Rainier in Washington State on June 10. "I went out to get a photo of the moon directly over Tahoma (Mt. Rainier) but I saw the ferry coming and wanted to include it in the photo," Raught told in an email. "Rather than wait for the moon to align with the mountain, I decided to instead catch the ferry at the last possible moment before it disappeared behind the building on the pier," explained Raught. "I wanted to preserve the detail in the moon, so I opted for less light in the photo overall. I was happy that the sailboat was positioned so perfectly at this moment, it adds a wonderful detail to the photo." Andrew von Rathonyi took a different approach when eyeing the moon from the town of Irondequoit, New York, choosing to frame the celestial body as it appeared to graze the top of a low-hanging cloud, illuminating its fringes with reflected sunlight. One particularly striking shot was captured by Ahsan Mohammed Ahmed Ahmed in the city of Halabja, Iraq, which featured the silhouette of a man playing the violin on a hillside, framed by the rising form of the full moon. Ismael Adnan Yaqoob was able to snap the Strawberry Moon as it rose above a ferris wheel in the Iraqi city of Duhok on the night of June 10, at which point it had moved further from the horizon, losing the orange glow of moonrise. Photographer Isla Terli was able to snap the silhouette of a passenger airliner from Turkey as it passed across the face of the full Strawberry Moon, along with the prominent craters, ejecta rays and lunar seas that mark its surface. Twitter/X user @VeronicaJoPo caught the Strawberry Moon traveling low over Ely Cathedral in the town of Little Downham, Cambridgeshire, in the UK around the full moon phase. Finally, photographer Isla Terli was able to capture this atmospheric shot of the Strawberry Moon rising over the Selimiye Mosque in the Turkish city of Edirne, soon after it had emerged from below the southeastern horizon. Remember, the Strawberry Moon will appear almost completely lit in the nights following its full moon phase, which occurred at 3:44 a.m. EDT (0744 GMT) in the early hours of June 11 for viewers in New York. Editor's Note: If you capture a picture of the Strawberry Moon and want to share your astrophotography with readers, then please send your photo(s), comments, name and location to spacephotos@