Welcome back Stargazers!
I hope everyone thoroughly enjoyed the spectacular Blood Moon on March 3, 2026.
The next Blood Moon won’t be until December 31, 2028!
This month we’ll learn about the planet Mercury, starting with its astronomy and folklore. It’s the smallest and innermost planet in the solar system. Despite Mercury’s closeness to the Sun, it remains one of the most mysterious and difficult to observe of the celestial bodies, due to solar glare and its extreme environment. Mercury has a short orbit of only 88 days. Because its orbit lies between the Earth and the Sun, it doesn’t appear from our terrestrial perspective ever to be very far from the Sun. In an astrology chart, Mercury can never be further away from the Sun than 28 degrees.
Mercury is the second most dense planet after Earth, featuring a massive metallic core, believed to be partially molten, that makes up about 85% of its radius. Its extremely hot surface is heavily cratered, very similar in appearance to the Moon. Mercury is also referred to as the ‘elusive planet’ since it stays close to the Sun and is only visible from Earth just before sunrise or just after sundown – appearing often as the Morning or Evening Star.
Fun fact: Mercury’s orbit precession* provided a crucial, early confirmation of Albert Einstein’s General Theory of Relativity (1905-1915). For decades, astronomers were baffled by a ‘glitch’ in Mercury’s orbit. It didn’t follow the rules set by Isaac Newton (1665-1667). But by solving the mystery, astronomers had the first major proof that Einstein’s view of the universe was correct. According to Newton’s laws of gravity, planets should orbit the Sun in perfect ellipses. Due to the gravitational pull of other planets (like Jupiter and Earth), these ellipses slowly rotate over time. *This rotation is called ‘precession.’
By the mid-1800’s, astronomers had calculated exactly how much Mercury’s orbit should rotate. But when they looked through their telescopes, they found a tiny, stubborn discrepancy:
1. Mercury was ‘precessing’ slightly faster than Newton’s math predicted.
2. The difference was tiny – but in science, even a tiny error means a theory is
incomplete.
Before Einstein, scientists were so sure Newton was right they had assumed there must be an undiscovered planet hidden even closer to the Sun, pulling on Mercury.
Astronomers spent decades searching for this planet named ‘Vulcan’, but it never appeared. In 1915, Einstein applied his new General Theory of Relativity to Mercury. He realized that gravity isn’t just an invisible “tug” between masses; it’s the warping of space and time itself. Because Mercury is so close to the Sun, it sits in a region where space/time is extremely curved. This curvature adds a tiny bit of extra strength to the Sun’s gravity, for which Newton’s equations didn’t account. This is important, since it was the first time a ‘modern’ theory had solved a problem that ‘classical’ physics simply couldn’t. Mercury’s orbit proved that the Sun’s mass actually bends the fabric of the universe, confirming that Einstein’s radical new geometry of the cosmos was real.
I found this tidbit of information unbelievably interesting and my own “a-ha!” moment. I hope readers find this fun as well.
Now for the Folklore and Legends surrounding Mercury:
Ancients viewed this planet as a swift messenger or a clever traveler, associating Mercury with speed, communication, and meditation due to its rapid movement across the sky. Most legends surrounding this planet are tied to ancient deities, such as:
Mercury – Roman god of commerce, travel – and thievery. He is the son of Jupiter and Mara, and served as the messenger of the gods. Mercury is identified by his winged sandals and winged hat (found commercially with Goodyear’s winged foot and Aston Martin’s wings). As this special envoy of the gods, he bridged the gap between the divine and the mortal worlds and served to guide the spirits of the dead. Mercury is also the god of trade and commerce, as well as of trickery and thievery. Roman legend says that just five minutes after his birth, he stole a herd of cows from his brother Apollo.
Buddha – Hindu god of intelligence, communication, and humor. With a fluid gender identity, spending periods as a man and a woman, this contributes to the planet’s astrological association with adaptability and neutrality.
Mercury might be one of our most interesting, yet most unknown of our planets. I hope you enjoyed my ‘fun fact’ … and other fun facts may turn up in future blogs.
Keep a weather eye toward the heavens this month. Happy stargazing until next time!
Yours in the Stars,
Astrid