The universe changed on August 28, 1758. Early that morning, as he scanned the predawn sky for Halley's Comet on its predicted return, the French comet hunter Charles Messier found something he had never seen before through his telescope. The mysterious object, lying just off the southern "horn" of Taurus, the Bull, looked just like a comet through his small refractor. Returning over the course of the next two weeks, Messier realized that what he had found could not be a comet, since there was no telltale indication of orbital motion.  Instead, it remained anchored in place. Messier noted the position of his unexpected discovery, and was later to include it as the first entry in a catalog of annoyances that might fool him and his fellow comet hunters into thinking they too had found a new comet. The rest, as they say, is history. (To be correct, Messier was not the first person to see M1. That distinction belongs to London physician and amateur astronomer John Bevis, who discovered it 27 years earlier.)

The story of M1, of how it is the expanding remnant of a massive star that detonated in a huge supernova explosion, is well known to most. That explosion was witnessed by ancient Chinese and Anasazi Native American stargazers in July 1054 AD. Although half a world away from each other, both recorded the exploding star's sudden appearance. At its peak, the supernova may have shone as brightly as magnitude -6 and was visible in broad daylight for nearly a month.

Today, when we look toward the site of the supernova explosion, all we see is the expanding cloud of debris that we call the Crab Nebula. The nebula got its nickname in 1844 when British astronomer William Parsons, the Third Earl of Rosse, observed it through his telescope and sketched its appearance. He noted that its intricate, filamentary structure resembled the legs and body of a crab. Although modern observations reveal a far more complex and dynamic structure, the name "Crab Nebula" has persisted, serving as a historical nod to Parsons' interpretation of its appearance during the early days of astronomical study.

The nebula’s elaborate structure seen in photographs consists of expanding filaments of ionized gas, primarily hydrogen, helium, and heavier elements like oxygen and carbon, traveling at 1,500 km/second. Its synchrotron radiation, generated by high-energy electrons spiraling in magnetic fields, makes the Crab Nebula a strong emitter across the radio to gamma-ray spectrum. At its core lies the Crab Pulsar, a rapidly spinning neutron star emitting powerful beams of radiation.

On a personal level, the universe changed for me in January 1972, and M1 was the reason.  It was a cold winter night, with snow on the ground and crystal clear skies overhead.  Outside in my backyard, I had my new 8-inch reflector, my trusty Skalnate Pleso Atlas of the Heavens, and a pair of 7x35 binoculars.  Wearing a heavy parka to insulate me from the cold, I laid back against a pile of snow, enjoying the sky with the binoculars as I waited for my telescope's optics to acclimate to the cold temperature.  As I made my way past many winter favorites, I happened to scan along the southern horn of Taurus.  Third-magnitude Zeta (ζ) Tauri marks the tip of the horn.

Through the binoculars, I could also see nearby 6th- and 7th-magnitude stars that, with Zeta, formed a small trapezoid that I had used in the past to find M1 through my reflector.  Looking more closely at the field, I thought I could see the dimmest smudge of light nearby.  Sure enough, I was seeing, ever so faintly, M1 through the binoculars.  That one observation convinced me about the potential of binoculars and began my lifelong pursuit of pushing them to their limits, which I enjoy doing to this day.

With 10x and lower-power binoculars, M1 looks like a rounded rectangle of grayish light (as illustrated above).  That's an unusual shape in a universe of round and oval nebulae.  Like many smaller deep-sky objects, M1 benefits from magnification and smaller exit pupils.  Under dark skies, it appears much more obvious through a pair of quality 16x50 binoculars than through similar 10x50s, and even more so than through 7x50 binoculars.  The secret to seeing it is to brace the binoculars against something, whether that something is a tripod, a fence post, or, yes, even lying in a pile of snow.

Good luck with this month's Cosmic Challenge! And be sure to post your results in this column's discussion forum.

Until next month, remember that half of the fun is the thrill of the chase.  Game on!